ID 1 Flashcards
1
Q
What is the risk of mortality from IE due to strep viridans infection of prosthetic valves vs. of native valves?
A
Prosthetic valves: 20%Native valves: 5%
2
Q
What are the 7 indications for prophylaxis against IE in patients undergoing dental procedures?
A
- Previous infective endocarditis2. Prosthetic cardiac valves3. Cardiac transplant recipients who develop cardiac valvulopathy4. Unrepaired cyanotic congenital heart disease (including palliative shunts and conduits)5. Completely repaired cyanotic CHD with prosthetic material or device during the first 6 months after procedure (ie. until endothelialization of prosthetic material occurs)6. Repaired CHD with residual defects at site of prosthetic patch or device (incomplete endothelialization)7. Rheumatic heart disease if prosthetic valves or material used in valve repair
3
Q
What is the most common underlying condition that predisposes to the acquisition of IE in the western world?-prophylaxis prior to dental procedure?
A
Mitral valve prolapse-no abx prophylaxis since the absolute incidence of IE is extremely low in this population AND IE with MVP is usually not associated with horrible outcomes as in cyanotic CHD
4
Q
Which dental procedures require abx prophylaxis for IE?
A
- Manipulation of gums2. Involvement of periapical region of teeth3. Perforation of oral mucosa
5
Q
What is the preferred antibiotic for IE prophylaxis prior to dental procedure? -dose?-when to administer?-2nd option for allergic people
A
Amoxicillin (well absorbed, high serum concentrations)-50 mg/kg x 1 dose 30-60 mins before procedure OR up to 2 hrs after-2nd options: clindamycin or clarithromycin
6
Q
What respiratory tract procedures requires IE abx prophylaxis for high risk patients?
A
Any procedure that involves incision or biopsy of the respiratory mucosa-ex. T&A
7
Q
What GI or GU tract procedures requires IE abx prophylaxis for high risk patients?
A
Prophylaxis is no longer recommended in these patients UNLESS they already have an established GI or GU tract infection, then the abx should have activity against enterococcus (amp or vanco)
8
Q
What are the 3 most common clinical presentations of invasive group A strep infections?
A
- Soft tissue infection: Nec fasc or myositis2. Bacteremia 3. Pneumonia
9
Q
In which group is nec fasc more common: < 5 yo children or > 5 yo children?
A
<5 yo (5x higher)
10
Q
In pediatric populations, what is a prominent risk factor for developing an invasive GAS infection?
A
Varicella infection
11
Q
What is the diagnostic criteria for GAS Toxic Shock Syndrome?
A
Hypotension + at least two of the following:1. Renal impairment2. Coagulopathy (decreased platelets or DIC)3. Liver enzyme or function abnormality4. ARDS5. Generalized erythematous macular rash that may desquamate **Think hypotension + involvement of at 2 organ systems (heme, renal, liver, derm, lungs)
12
Q
Who is considered a close contact of a person with invasive GAS infection? (7)
A
- Household conatcts who have spent at least 4 hr per day on average in previous week 2. Shared the same bed or had sex3. Direct mucous membrane contact (kissing, mouth to mouth resusc, touched open skin lesion)4. Injection drug users who shared needles5. Share long term care facility6. Share home daycare7. Selected hospital contacts
13
Q
What is the recommendation on who should receive chemoprophylaxis for GAS invasive infection?-when should chemoprophylaxis occur?-what advice should be given to close contacts?
A
Who should receive:1. Close contacts of a confirmed case of SEVERE GAS invasive infection (TSS, nec fasc, meningitis, pneumonia) who have been exposed during the period from 7 d before onset of symptoms in the case to 24 hr after the initiation of abx in the case-chemoprophylaxis should start ASAP (within 24 hr of case identification is ideal but can be up to 7 d after the last contact with the case)-advise close contacts on s/s of GAS infection and to see MD asap if febrile or other s/s of GAS within 30 days of diagnosis in index case
14
Q
What is the definition of confirmed case of GAS?
A
Laboratory confirmation of GAS infection (isolation of GAS from a normally sterile site) with or without clinical evidence of invasive disease
15
Q
What is the preferred chemoprophylaxis agent for close contacts of GAS invasive infection?-alternative agents?-alternative agents for beta-lactam allergy?
A
1st generation cephalopsporin (cephalexin)-alternative agents: 2nd or 3rd generation cephalosporin (cefuroxime axetil and cefixime)-beta lactam allergy: macrolides (but concern with macrolide-resistant GAS) or clindamycin**NOTE: penicillin is LESS effective than cephalosporins for eradicating GAS COLONIZATION
16
Q
What is the recommendation on whether routine cultures should be drawn on close contacts of GAS invasive infection receiving abx chemoprophylaxis?
A
No routine cultures are required unless symptomatic
17
Q
What is the antibiotic of choice for treating severe invasive GAS infection?-additional treatment to minimize/neutralize the effects of toxin production?-additional treatment of GAS toxic shock syndrome?
A
Treatment of choice: penicillin (no resistance to date)-add clindamycin to inhibit protein synthesis and thus decrease toxin production (should never be used as monotherapy though since 1-2% of GAS is resistant to clindamycin)-for GAS TSS, add IVIG single dose 1-2 g/kg
18
Q
What is Palivizumab?-dose, route, timing of administration-how much is a dose?
A
RSV-specific monoclonal antibody - used for preventing and reducing RSV hospitalization rate of high-risk children-15 mg/kg IM q30days during RSV season x 5 months max-cost of 1 dose: ~$1100-no evidence showing that it prevents significant mortality
19
Q
The majority of RSV hospitalizations occur in what group of infants?
A
Term infants with no pre-existing risk factors
20
Q
What is the drug efficacy of palivizumab for prevention of RSV and associated hospitalizations?
A
55%
21
Q
Which high-risk children should receive palivizumab to prevent RSV hospitalization? (3)
A
- Children with CLD who require ongoing medical therapy2. Children with hemodynamically significant CHD who are younger than 2 yo at the start of RSV season (November-ish)3. Infants < 32 wks GA who are younger than 6 months of age at the start of RSV season
22
Q
What is the recommendation for use of palivizumab in children born between 32 wks-35+6 wks GA?
A
- Depending on provincial funding available, should come up with a policy on which of these infants should receive palivizmuab2. Can apply AAP criteria which involves day care attendance/living with a child < 5 yo, chronological age < 3 months at time of each dose of palivizumab (ie. last dose should be at 3 months chronological age)
23
Q
What is the recommendation for use of palivizumab in infants in remote communities who would require air transport for hospitalization?
A
- Should consider giving to babies born < 36 wks GA and who will be less than 6 mo of age at beginning of RSV season-give up to 5 doses2. Should consider giving to term Inuit infants < 6 mo in communities with documented persistent high rates of RSV hospitalizations
24
Q
What is the recommendation for use of palivizumab in children with immunodeficiencies, Down syndrome, cystic fibrosis, upper airway obstruction or a chronic pulmonary disease other than chronic lung disease of prematurity?
A
Not routinely recommended BUT may be considered for children
25
What is the incubation period of chicken pox?
10-21 days after contact
26
When is the highest concentration of VZV DNA detected in the nasopharyngeal secretions in terms of day of rash? -when is transmission the greatest?
Highest concentration on day one of rash-the children with the highest level of ciremia will obviously be the sickest with higher fevers and more vesicles-transmission is the greatest in the prodrome period (the day before onset of rash)
27
What is the policy for isolation precautions in hospital for children with known exposure to chicken pox?
When a child has been exposed to chicken pox and is staying in hospital, they should be placed in isolation from day 8-day 21 from the day of contact (since incubation period is 10-21 days before they'll be able to transmit the virus to others so you're starting 2 days before the shortest incubation period)) -prevents other children on the ward from being exposed to VZV in the days before the exposed child develops the overt rash
28
What is the recommendation on when a child with mild chicken pox can return to school or daycare?
Should be allowed to return to school or daycare as soon as they are well enough to participate normally in all activities, REGARDLESS OF THE STATE OF THE RASH
29
When would you order a CBC and blood culture in a child diagnosed with pneumonia? (2)
1. Clinically worsening2. Hospitalized
30
What are features of atypical pneumonia (ie. mycoplasma pneumoniae)? (5)-treatment?
1. Subacute onset2. Prominent cough3. Minimal leukocytosis4. Nonlobar infiltrate5. School aged child-treatment: clarithromycin or azithromycin
31
What is the antibiotic treatment for:-nonsevere pneumonia-severe pneumonia
Nonsevere: high dose amoxil or amp IVSevere: ceftriaxone IV or cefotaxime IV plus clarithromycin PO or azithromycin PO/IV
32
What is the treatment for a child with proven or clinically suspected influenza plus evidence of secondary bacterial pneumonia?
1. Consider adding antiviral for influenza2. Amoxi-clav PO or cefuroxime IV for non severe3. Ceftriaxone IV or cefotaxime IV + clarithromycin PO or azithromycin PO/IV**some experts recommend adding cloxacillin
33
What is the treatment for a child with pneumonia and moderate-to-large effusion?
1. Consider pleurocentesis2. Ceftriaxone or cefotaxime IV**some experts recommend adding clindamycin
34
What is the treatment for a child with pneumonia that could be due to MRSA?
1. Add vancomycin or linezolid to the antibiotic you've aleady started (ie. Amoxil, ampicillin, cephalosporins)
35
What is the rationale for using 3rd generation cephalosporin in treating severe pneumonias (ie. what makes it better than amoxil or amp?)
1. May offer better coverage for pen-resistant pneumococcus (controversial)2. Better coverage for H flu and moraxella catarrhalis (rare in healthy, immunized children)
36
What is the management of a patient with pneumonia who failed to improve after 48 hrs of therapy with a beta lactam alone?
1. CXR to r/o empyema2. Consider adding clarithromycin or azithromycin for atypical pneumonia
37
What features are seen in exudative pleural effusion? (5)
1. Low glucose (1000)3. High WBCs4. Bacterial growth5. Low pH (<7.2)
38
What is the treatment for pneumonia in a child with penicillin allergy?
Non severe pneumonia:-outpatient Clarithromycin or azithromycin PO-keep in mind that strep pneumo resistance to these medications is growingSevere pneumonia:-discuss with peds ID if the allergy is true IgE-mediated-if it wasn't, then can use cephalosporins (cefuroxime)-keep in mind strep pneumo is better covered by Ampicillin than 2nd gen cephalosporin
39
How do young infants present clinically with influenza compared to older children?
Less likely to have cough and pneumonia; more likely to have rhinorrhea and dehydration
40
What are two recommended strategies for decreasing seasonal influenza risk in infants < 6 months?
1. Immunize caregivers and family of the infant2. Immunize pregnant woman-cost-effective compared with supportive treatment of influenza illness once the pregnant woman gets it-also NNT to see decreased influenza cases in young infants is 17!
41
Name 5 ways pediatricians can increase influenza protection for young babies?
1. Educate pregnant women or women planning to become pregnant to get influenza vaccine2. Encourage them to get the vaccine as soon as it is avaialble before the influenza season starts3. Update medical colleagues who deal with pregnant women to advocate for influenza immunization4. Encourage hand hygiene5. Encourage and facilitate whenever possible influenza immunization of all household contacts of infants younger than 6 mo of age
42
What is the pathogen that causes lyme disease?-which tick species in Canada carry the pathogen? (2)
Pathogen: Borrelia burgdorferi-transmitted by Ixodes scapularis tick in Eastern Canada and Ixodes pacificus in Western Canada (black legged ticks aka deer ticks)-10-12% of these ticks may carry Borrelia burgdorferi-chances of catching Lyme disease are quite low though except in areas where the Eastern and Western black-legged tick populations are firmly established
43
Where in Canada are ticks carrying lyme disease well-established? -Eastern Canada (3)-Western Canada (1)
Western Canada: BC (especially Fraser Valley, lower mainland, Vancouver island)Eastern Canada: Ontario (Lake Erie, Lake Ontario), southeastern Manitoba, Nova Scotia (Bedford, Lunenberg)
44
What are the most common ticks found on people and pets in Canada?-can you catch lyme disease from these ticks?
Most common dicks: American dog tick (Dermacentor variabilis) & groundhog tick (Ixodes cookei) = cannot transmit lyme disease
45
What 4 systems are affected in lyme disease?
1. Skin (most common): erythema migrans2. Joints (50%): arthalgia, arthritis (usually involving knees)3. CNS (10%): headaches, facial nerve palsy (most commonly), meningitis4. Heart (5%): AV block
46
What is the most common early clinical manifestation of Lyme disease?-when does it typically appear in relation to detachment of the tick?
Erythema migrans (because ticks MIGRATE)-starts as red macule or papule that rapidly expands in a circle with central clearing reaching at least 5 cm in diameter-appears 7-14 days after detachment of the tick
47
How do you diagnose Lyme disease?-what is the lab test?-what is the timing for the test?
If a patient presents with erythema migrans and has been exposed to a region where black legged tick is well-established, diagnosis is made on clinical grounds alone.-if patient with erythema migrans is in region where black legged ticks are found but not established, need serological testing for B burgdorferi-Diagnostic testing (2 step test): 1. Step 1: B. burgdorferi IgM -timing: at clinical presentation AND in 4 weeks time if initial test negative (due to delayed antibody response)2. Step 2: If IgM positive, confirm with Western blot
48
Why are there a lot of false positive Lyme disease diagnostic results in certain area of the U.S?
Alot of private labs in the U.S do not do the 2 step test (ie. they do not confirm a positive IgM with a Western blot)-even with 2 step test however, the likelihood of a false-positive is high in a low prevalence area such as Canada
49
What is the treatment for Lyme disease?-early lyme disease (ie. erythema migrans)-CNS lyme disease-CVS lyme disease-Lyme disease arthritis
Early lyme disease (erythema migrans): -children < 8 yo: Amoxil 50 mg/kg/day div TID or cefuroxime axetil 30 mg/kg/d div BID-children > 8 yo: doxycyclin 4 mg/kg/d div BID x 14-21 daysCNS lyme disease:-IV ceftriaxone x 14-28 d-facial nerve palsy MAY be treated with PO abx but talk to ID firstCVS lyme disease (heart block): IV ceftriaxone with switch to PO when improved x 14-21 dArthritis: PO amoxil or doxycycline x 1-2 mo until improvement in swelling-if no improvement after 2 mo, IV ceftriaxone
50
What is the management of persistent Lyme disease arthritis that has not responded to PO or IV abx?
1. NSAIDs2. Consult with Lyme disease expert3. Hydroxychloroquine (antiinflammatory and antispirochetal effect)4. If persists > 1 yr, may need arthroscopic synovectomy
51
In which populations does the TST have poor sensitivity (ie. false negatives)? (4)
1. Infants and very young children3. Immunocompromised pts4. Patients with active and/or disseminated TB infection5. Recent MMR vaccination
52
In which populations does the TST have poor specificity (ie. false positives)? (3)
1. Previously vaccinated individuals with BCG2. Individuals with non-TB mycobacterium
53
What are the 5 indications for targeted TB screening with a TST in children?
1. Children with suspected active TB disease2. Children of known cases of active TB3. Children with known RFs for progression of infection to disease (ie. immunocompromised) or starting immunosuppressive therapy4. Children who arrived in Canada from countries with high TB incidence within the last 2 years5. Children travelling or residing for 3 or more months in area with high incidence of TB
54
What is the IGRA test?
Interferon gamma release assay = measures in vitro production of interferon gamma by sensitized lymphocytes in repsonse to Mycobacterium tuberculosis antigens-this is specific to TB since BCG vacine and non-TB mycobacterium do not produce these antigens and thus would not get interferon gamma release by lymphocytes= fewer false positives than TST
55
What are the recommendations for the use of IGRA in diagnosing LTBI?-what about immunocompromised children?
1. Order an IGRA when you suspect a false-positive TST result in a child who has a low risk probability for LTBI and no risk factors for progression to active disease - overall, to CONFIRM that positive TST is actually true2. In immunocompromised children, TST should still be the first initial test to be ordered to r/o LTBI-if TST is positive, the child is considered to have LTBI-if TST is negative and you are still concerned about LTBI, then do an IGRA***IGRA SHOULD NEVER BE USED IN ISOLATION TO DIAGNOSE TB DISEASE-should still try to get microbiological confirmation of active TB
56
Does a negative IGRA or TST rule out active TB?
NO! -remember that both can be falsely negative in active TB disease
57
What are the risk factors for the development of latent TB --> active TB?-high risk (6)-increased risk (6)-low risk (1)
High risk:1. Immunocompromised: HIV/AIDS, post-transplant patients2. Chronic renal failure needing hemodialysis3. Recent acquisition of TB (2 years or less) = highest risk of activated TB is within 2 years of contracting it4. Head and neck cancer5. Silicosis6. Abnormal CXR with fibronodular diseaseIncreased risk:1. Glucocorticoid use2. Diabetes mellitus3. malnourished4. Young age (0-4 yo)5. Smoker6. Abnormal CXR (granuloma)Low risk:1. Infected person (LTBI) but no risk factors and normal CXR
58
When a child presents with a fever, when should a urinalysis and urine culture be sent?
< 3 yo with fever > 39 rectal with no apparent source
59
Should you consider UTI in children presenting with bronchiolitis?
No; although positive urine cultures are often found with bronchiolitis, most of these are either contamination or asymptomatic bacteruria in infants > 2 months of age
60
According to systematic reviews, what clinical features when present together in an infant < 24 months are highly suggestive of a UTI? (3)
1. Fever > 39 rectal2. Fever > 48 hours3. No other source for fever
61
What is the predictive rule for ruling out UTI in girls < 24 months? (5 criteria)
When no more than one of the following features are present, the risk of UTI is < 1%:1. Age < 12 months2. White race3. Temperature > 39 R4. Fever > 48 hrs5. Absence of another source for fever
62
Which organisms will give you a positive nitrite on urinalysis?
Gram negative bacteria
63
What is the sensitivity and specificity for pyuria in diagnosing UTI?
Sensitivity: 73%Specificity: 81%
64
What is the chance of a UTI in a child with negative urine dipstick for nitrites and leukocyte esterase and no pyuria or bacteruria on microscopic examination?
<1%
65
What is the sensitivity and specificity of the following for UTI:-Leukocyte esterase (LE)-Nitrites (NT)-Either LE or NT +-WBCs (pyuria)-Bacturia-LE, NT or microscopy positive
-LE: sensitivity 83%, specificity 78%-NT: sensitivity 53%, specificity 98%-Either LE or NT positive: sensitivity 93%, specificity 72%-WBCs: sensitivity 73%, specificity 81%-Bacturia: sensitivity 81%, specificity 83%-LE, NT or microscopy positive: sensitivity 99.8%, specificity 70%
66
What are the minimum colony counts that are indicative of a UTI on culture?-clean catch (midstream)-in/out cath-SPA
-clean catch: >10^5 CFU/ml or >10^8 CFU/L-cath: >5 x 10^4 CFU/ml or >5 x 10^7-SPA: any growth
67
When should blood cultures be drawn in a patient with clear diagnosis of UTI?
Only when the child is hemodynamically unstable: there is no evidence that documentation of bacteremia in children with UTIs should influence therapy
68
What is the evidence on full IV abx course vs IV + step down to PO abx course vs PO abx course only in acute pyelonephritis in previously healthy children (age > 2 mo) with normal kidneys?
Cochrane review found no difference between oral abx (10-14 days) and IV abx (3 d) + step down to PO abx (10 d) for duration of fever or subsequent renal damage.Also so difference between IV abx (3 d) + step down to PO abx (10 d) vs IV abx alone x 7-14 d. Thus can use PO abx for febrile UTIs in nontoxic children with no known structural urological abnormalitySome experts recommend IV abx for ages 2-3 mo since data on PO abx is limited
69
Which empirical abx is good starting treatment for UTI while waiting for culture results? -PO-IV
-PO: cefixime (3rd generation cephalosporin)-IV: gentamicin(Some people use cefotaxime or ceftriaxone but these are broader spectrum)
70
When should aminoglycoside levels and renal function be monitored during UTI therapy?
Monitor when the aminoglycoside is continued > 48 hrs
71
What is the most common cause of UTI without fever?-treatment course
Lower tract infection (cystitis)-treatment course: PO abx x 2-4 d course
72
What are features of a complicated UTI? (6)
1. Hemodynamic instability2. Bladder or abdominal mass3. Poor urine output4. Elevated creatinine5. No clinical improvement within 24 hrs of abx6. No improvement in fever trend within 48 hrs of abx
73
What is the management of a complicated UTI?
1. Renal and bladder ultrasound to look for obstruction or abscess2. IV abx until clinical improvement
74
What is the management of a UTI with multiresistant organism that is only susceptible to quinolones?
Quinolones are not licensed for use in prepubertal children...BUT may be appropriate if the organism is resistant to other oral abx
75
What is the management of a UTI with multiresistant organism in a child who actually improved on empiric treatment that the bug was resistant to?
Unclear whether improvement is because organism is susceptible to high concentration of antibiotic that is achieved in urine or because the urine was contaminated initially-if asymptomatic, repeat the UA and urine culture and change therapy only if results are suggestive of persistent UTI-if symptomatic, repeat UA and urine culture and change abx based on results
76
What imaging study should be ordered for children < 2 years of age with:-a first febrile UTI?-second febrile UTI?
1st febrile UTI:-Renal ultrasound - should be done within 2 weeks of their acute illness-reliably detects hydronephrosis which usually occurs with high grade (4 & 5) VUR-if you see this, then order VCUGSecond febrile UTI:-VCUG for sure
77
What is the recommendation for antibiotic prophylaxis in children with VUR?
No abx prophylaxis for grade 1-3 because the number needed to prophylax for one year to prevent one UTI is > 10. Only prophylax for grades 4-5
78
When performing VCUG, what is the evidence regarding:-postponing VCUG until child finishes antibiotics?-antibiotic prophylaxis until VCUG completed?-what are two diagnoses you can make using VCUG?
Postponing VCUG until finished antibiotics: no evidence that this is necessaryAbx prophylaxis: controversial***VCUG: 1. Posterior urethral valces2. Vesicourethral reflux
79
What is the appropriate way to obtain a urine sample from a toilet trained child?
Midstream urine sample
80
What is the recommended duration course of antibiotic treatment for infants and children with febrile UTI? -oral vs. po-what if UTI is accompanied by a positive blood culture?
7-10 days-If child has no other indication for admission to hospital and is considered likely to receive and tolerate every dose, can use oral antibiotics as initial treatment-no evidence that children with UTIs and documented bacteremia who have a rapid clinical response to abx require IV abx or a longer course of abx-positive blood culture: can continue PO abx BUT all children need to be assessed by a physician the day that the blood culture is known to be positive
81
What is the optimal time to remove a tick to prevent lyme disease?
24-48 hrs of attachment as the bacteria will not yet have been transmitted
82
How do you remove a tick?
1. Use fine tipped tweezers to grasp the tick close to the skin surface2. Pull upward with steady, even pressure (no twisting or jerking since this can cause the mouthpart to break off and remain in the skin)3. Clean the bite area and your hands well4. Put the tick in a clean container and call local public health
83
What bacteria causes lyme disease and which species in Canada carries it?
Borrelia burgdorferi-in Canada, only the black legged tick carries it
84
What are Health Canada's recommendations on the safety of DEET in insect repellent?
For children < 12 yo: use only products with < 10% DEET and should not be used for exposures lasting longer than 1-2 h because this low percentage will not be effective in preventing bites after thatFor children > 12 yo, use only products with < 30% DEET
85
What are Health Canada's recommendations on the use of insect repellent in infants < 6 mo?
Health Canada has not evaluated the safety of repellents for infants in this age group so better not to use chemical measures in this population
86
What are the adverse effects of DEET? (3)
1. Contact dermatitis - most common2. Eye irritation3. Toxic encephalopathy - has been reported with prolonged/excessive use or ingestion
87
What is the evidence of efficacy and safety when comparing DEET with Icaridin/picaridin?
-Icaridin/picaridin has levels of efficacy similar to DEET-No evidence that DEET-free repellents are safer
88
What is the repellent of chioce by the Public Health Agency of Canada's Canadian Advisory Committee on Tropical Medicine and Travel for travellers 6 mo - 12 yo?
Icaridin!-up to 20% Icaridin is considered to be safe and efficacious-in 2013, only Avon products containing icaridin were available in Canada
89
Does 5-10% DEET products protect against both mosquito and tick bites? Duration of action?
The efficacy of 5-10% of DEET against ticks is not certain! Products with > 10% does repel ticks though. Duration of action is 2-3 h.
90
Does 10-20% Icaridin products protect against both mosquito and tick bites? Duration of action?
Yes! They also last longer than DEET products (5-7 h)
91
Do insect repellents containing lemon eucalyptus oil or soybean oil protect against both mosquitoes and tick bites? Duration of action?
Protect against mosquitoes but not necessarily ticks (same duration of action as 10% DEET). Duration of action is approximately 2-3 h.
92
Are natural repellents safer than DEET or icaridin? What is the next best choice if cannot use DEET or icaridin?
Natural repellents (ie. lemon eucalyptus or soybean oil) aer not necessarily safer! People who are sensitive to plant oils may develop dermatitis or eye irritation!-next best choice: PMD (p-methane 3,8 diol) = synthetic derivative of lemon eucalyptus
93
What is the recommendation of use for PMD-containing repellents?
Use only in individuals > 3 yo
94
What is the recommendation on use of products with combined repellent and sunscreen?
Avoid these products! Sunscreen needs to be reapplied more frequently than repellent. If putting them on separately, put on sunscreen first, allow to penetrate for 20 minutes, then apply repellent.
95
How do you use permethrin products?
Not licensed to be applied as topical repellent but can be sprayed on clothing/bed nets/etc. May retain effects up to 2-6 washings. Safe for most mammals EXCEPT cats!
96
What is the possible side effect of palivizumab?
Anaphylaxis
97
How common are biting episodes in child care settings?-what is the general risk of transmission of infection via biting?
Based on 2 studies, can expect that for children younger than 3 yo, there would be one biting episode per day, of which one every 8-10 wks would break the skin-most bites do not result in blood exposure and thus transmission of viruses is extremely low
98
How is hepatitis B transmitted?-transmission via bite?
Contact of mucous membranes or open skin lesions with blood, saliva or genital secretions from actively infected individuals-can be transmitted via bite only if bite breaks the skin
99
In which two clinical situations would HBV prophylaxis be warranted in biting incidents at daycare?-what is the risk of transmission of HBV from a biting child?
1. If the biter is HBV positive and breaks the skin of the bitten child, the bitten child should receive postexposure prophylaxis since their blood came into contact with infected mouth2. If the bitten child is HBV positive and has skin broken by the biter, the biter should receive postexposure prophylaxis since their mouth came into contact with infected blood-risk of transmission from a biting child is very low since HBV infection is rare in this age group in Canada (especially if infants received HBV vaccine)
100
Is routine screening of children attending child care for HBV/HIV warranted?-are parents required to divulge their child's HIV status to child care personnel?-can children be excluded from daycare based on HBV/HCV/HIV status?
No and NO!-parents may decide to inform the centre in consultation with the child's physician taking into consideration the child's immune status, behaviour and risk to the child of exposure to other pathogens at the child care centre (if they are immunocompromised)-it is UNETHICAL to exclude children from daycare based on infectious status
101
Has there been any reports of HIV transmission via bites in child care?-why is HIV less likely to be transmitted via bites than HBV?
No!-HIV is less likely to be transmitted via bites than HBV because saliva is inhibitory to the HIV virus whereas HBV can survive in saliva
102
What is the recommendation on when postexposure antiretroviral prophylaxis should occur after a bite by a child to prevent HIV?
Only in very rare and exceptional circumstances and should only be taken in consultation with ID
103
What is the risk of transmission of HCV after blood exposure compared to HBV and HIV?-is there postexposure prophylaxis therapy available for HCV?
HCV transmission after blood exposure is higher than HIV but lower than HBV-no postexposure prophylaxis available for HCV currently
104
What is the risk of bacterial infections from bites in very young children?
Very rarely lead to bacterial infections since they often don't have the strength to break the skin-routine wound care decreases the risk of infection to almost zero
105
What are the overall recommendations for daycare providers in regards to biting children? (5)
1. Each child care facility should have a written policy for managing child and employee exposure to blood and body fluids2. Staff should be adequately trained in caring for wounds3. First aid equipment should be available (gloves, skin disinfectant, dressings)4. All parents and personnel should be educated about blood borne viruses and informed that chance of acquiring this infection in child care settings is extremely low5. Parents should be informed that if a seriuos bite resulting in significant blood exposure occurs, parents of both children involved will need to be informed and the children may be referred for medical evaluation
106
A child who is a known HBV carrier exhibits frequent aggressive biting at daycare. What would you recommend?
Should be assessed on an individual basis and need to consider both the needs of the child and the ability of the centre to safely provide care required-may need to move child to a smaller family-oriented setting with less children and potentially less frustrating circumstances for the child to decrease biting-may need behavioural interventions with specialist consultation
107
What are measures that may help decrease biting incidents in daycare?
1. Avoidance of stressful situations, frustrations and conflicts2. Provision of age appropriate small group activities3. Observation of how, when and why a child bites to help guide prevention and management4. Paying attention first to the victim, not the biter5. Firm statements to the biter that this is not acceptable behaviour and will not be tolerated6. Directing the biter to appropriate activities7. Positive reinforcement of appropriate behaviour8. Collaboration with the family
108
What are the recommendations for HBV prevention in a day care setting?
1. All daycare staff should be immunized against HBV2. Encourage all parents to get their children immunized against HBV
109
What is the management of a bite wound by day care staff?-if skin is not broken?-if skin is broken?
A. If skin is not broken: -clean the wound with soap and water, apply a cold compress and gently sooth the bitten childB. If skin is broken: -allow wound to bleed gently without squeezing-clean with soap and water.-apply a mild antiseptic. -File an official report-Inform parents of both the biter and bitten child within 2 hrs of the incident-report bite to public health who may elect to refer both children to physician for evaluation of risk of infection and possible need for postexposure prophylaxis -watch for signs of infection in next few days
110
A child is referred to your office for a bite which breaks the skin.-which clinical circumstances warrant the prophylactic use of antibiotics? (3)-what specific immunization should be reviewed and updated if necessary?
Clinical circumstances warranting use of prophylactic antibiotics:1. Moderate or severe tissue damage (unlikely with young children)2. Deep puncture wounds3. Bites to the face, hand, foot or genital area that are more than simple superficial abrasions (these are highly vascularized areas)**Review tetanus immunization status
111
A child is referred to your office who was bitten and the bite broke the skin. He has not received his HBV immunizations and the biter is known to be an HBV carrier. What do you do?
1. Hepatitis B immunoglobulin (0.06 ml/kg IM)2. HBV vaccine3. Arrange f/u to complete HBV vaccines and for HBV serology at 6 months after known HBV exposure
112
A child is referred to your office for biting another child which broke the skin. He has not received his HBV immunizations and the bitten child is known to be an HBV carrier. What do you do?
1. Hepatitis B immunoglobulin (0.06 ml/kg IM)2. HBV vaccine3. Arrange f/u to complete HBV vaccines and for HBV serology at 6 months after known HBV exposure
113
If a bite breaks the skin of a nonimmune child and the HBV status of the biter is not known OR if a nonimmune child bites a child of unknown HBV status, what is the management?
1. No HBV testing: there is a low risk of infection and thus, HBV testing is not justified.2. Nonimmune child should receive HBV vaccine (biter or bitten child)
114
If a child with known HIV infection bites or is bitten by another child and there is no blood in the saliva or in the bite wound, what is the management?
Nothing - no postexposure prophylaxis is indicated and there is no obligation to investigate or to disclose the child's HIV status.
115
A bite results in blood exchange by exposure of the buccal mucosa or broken skin to blood and one of the children involved is known to have HIV infection. What are the next steps in management?-indication for postexposure prophylaxis in this scenario?-relative contraindication for postexposure prophylaxis in this scenario?
1. Consult ID for advice2. Postexposure prophylaxis only if there is exposure involving DEEP bloody wounds (unusual in daycare setting)-if indicated, should be started within a few hours of the exposure-not indicated if more than 72 hrs have elapsed since bite3. Arrange f/u to check HIV serologies at 6 wks, 3 mo, 6 mo.
116
Is screening of children for HIV/Hep B or Hep C after a biting incident in child care warranted if status is unknown?
No!
117
If blood exposure after a bite is significant and one of the children involved is known to have Hep C infection, what is the management?
Appropriate f/u of the exposed child for serology testing at 6 mo-remember that there is no Hep C vaccine or Hep C postexposure prophylaxis
118
What is the prevalence of HCV infection in Canada?
1-3% but may be higher since majority of infected people are asymptomatic
119
HCV infection is most common in which 2 population groups?
1. Hemophiliacs who received untreated factor 8 concentrates2. IVDU
120
What are the major risk factors for HCV seropositivity in pregnant women? (3)
1. Previous or current IV drug use2. Being the sexual partner of an IVDU3. Blood transfusion before 1990
121
What is the method of acquisition of HCV by children prior to adolescence?
Perinatal exposure (almost exclusively)
122
What is the definition of chronic HCV infection?-what percentage of acute HCV infection cases become chronic?-what happens to the acute cases that do not become chronic?
Active viral replication >6 months as indicated by presence of HCV RNA in blood-75% of acute cases become chronic-other 25% appear to clear the HCV but usually have persistent HCV antibodies (small amounts of virus may still be detectable in the peripheral blood mononuclear cells and liver) and infectivity and incidence of sequelae is very low (although lack of long term studies to show prognosis)
123
What are the chances of spontaneous clearance of chronic HCV infection after 6 months in adults vs. children?
Adults: very unusual for this to happenChildren: 25-30% (usually occur by 7 yo)**Overall, spontaneous clearance is more likely in children than adults
124
Which of the following is false regarding long term prognosis of chronic HCV infection during childhood?a. Liver biopsies in children with HCV infection usually have grossly abnormal histologyb. Cirrhosis during childhood occurs in only a small percentage of childrenc. The majority of infected children have intermitent or chronically elevated liver enzymes.d. Most children remain clinically well with or without treatment
A is false: most children with HCV infection usually have mildly abnormal histology
125
A <2 mo baby born to an HCV-infected mother presents to your clinic and has the following bloodwork: HCV antibodies present, HCV RNA PCR negative. Interpret the results.
It is too early to say whether baby has or does not have HCV.-at this time, the antibodies may be maternal (thus no HCV) OR if transmission did occur, there hasn't been enough time for baby to be viremic yet if HCV positive (thus, false negative HCV RNA PCR)
126
A child 2-17 mo born to an HCV-infected mother presents to your clinic and has the following bloodwork: HCV antibodies present, HCV RNA PCR negative. Interpret the results.-next step?
Could be 1 of 2 scenarios: either vertical transmission of HCV did not occur (ie. the abs we are seeing are mom's) OR the child acquired HCV perinatally but cleared it, thus now protected with abs but no more viremia seen ****Given that the sensitivity of HCV RNA is < 100%, should repeat the HCV abs at >18 mo of age (when maternal abs have fully cleared). If negative, then child did not have HCV. If still positive, then repeat the HCV RNA PCR to ensure the HCV has really cleared.
127
What are the circumstances when HCV clearance can occur in children? (3)
1. In 25% of acute HCV cases2. In an undetermined small percentage of chronic HCV3. Successful antiviral therapy
128
A 2 yo child is referred to your clinic with the following bloodwork: HCV antibodies present, HCV RNA PCR negative. Interpret the results.
This child has had history of exposure to HCV (previous infection) but has now cleared the virus.
129
A 1 mo old baby born to an HCV infected mom presents to your clinic with the following bloodwork: HCV antibodies negative. Interpret the results.
Vertical transmission of HCV did not occur since there are no traces of maternal abs or own baby's immune system response to it.-this is true at any age!
130
A 5 mo child born to an HCV infected mother presents to your clinic with the following bloodwork: HCV abs positive, HCV RNA PCR positive. Interpret the results.
This is Acute HCV (since < 6 mo infection)-75% of acute HCV will progress to chronic HCV.
131
A 4 year old child presents to your clinic with the following bloodwork: HCV abs negative, HCV RNA PCR positive. Interpret the results.
Two possibilities:1. Seronegative (immunosilent) HCV - seen mainly in HIV coinfected adults or immunocompromised patients (incidence in children is unknown)2. Very very early acute HCV (typically 20-60 days prior to testing so no time for abs to develop yet)
132
A 6 yo presents to your clinic with the following bloodwork: HCV abs negative, HCV RNA PCR negative, HCV RNA present in liver or peripheral blood mononuclear cells. Interpret the results.
Occult HCV - has only been described in adults with elevated liver enzymes in research studies.
133
What is the transmission rate of perinatal HCV?-what are 4 risk factors for vertical transmission of HCV?
5%1. High maternal viral titre2. Elevated ALT in the year before pregnancy3. Presence of maternal cirrhosis4. HIV coinfection (as high as 25% HCV transmission)***unclear whether maternal IVDU increases risk of transmission
134
A pregnant woman presents to your office at the beginning of her 2nd trimester and she is coinfected with HIV and HCV. What do you recommend?
1. For all coinfected women past the 1st trimester, should start antiretrovirals to reduce the risk of transmission of both HIV and HCV. 2. Should also be screened for chronic hepatitis B infection
135
Which of the following is false:a. Pregnant women with HCV infection should undergo elective C-section to decrease rate of HCV vertical transmissionb. Infant female sex may be a risk factor for increased HCV vertical transmissionc. Procedures that promote mixing of fetal and maternal blood such as use of scalp electrodes or amniocentesis should be avoided due to risk of HCV vertical transmission
A!!! There is not enough evidence to recommend elective C section as a measure to decrease HCV transmission**Overall, there is no known method to prevent HCV vertical transmission
136
Is maternal HCV infection a contraindication to breastfeeding?-in which clinical circumstances should breastfeeding not occur? (2)
Not an absolute contraindication.-BFing does not appear to play a role in mother-to-infant transmission of HCV-may be because saliva and gastric acid rapidly inactivates HCV.-still warn moms that it is not possible to totally exclude the possibility that HCV transmission could occur via breastfeeding (studies have found HCV RNA in breastmilk) but benefits outweigh the theoretical but unproven risk of HCV transmission-breastfeeding should stop IF:1. mom experiences flare of chronic HCV infection with jaundice postpartum2. Cracked, bleeding nipples
137
What are the two potential long term complications of HCV infection?
1. End stage liver disease2. Hepatocellular carcinoma
138
Which women should be screened for HCV infection during pregnancy?
1. Past or present IVDU2. Recipients of blood products before 1990 in developed countries and/or at any time in developing countries3. Patients with unexplained elevated liver enzymes4. Patients who have undergone organ or tissue transplant from unscreened donors
139
A woman with HCV infection wants to get pregnant and wants to decrease risk of transmission to her baby. What do you advise?
Treatment of chronic HCV infection before pregnancy lowers risk of transmission but only advised if there are other indications for HCV therapy.-woman would have to agree to use effective birth control until they complete antiviral therapy since there have been no studies on how effective antivirals are when administered during pregnancy or how safe they are(ribavarin has been found to be teratogenic in animals)-remember that vertical transmission rate is only 5% (95% of women do NOT pass it on to their baby)
140
What is the primary diagnostic test for HCV infection in a baby born to an HCV positive mom and when would you do it?-when would you consider performing testing earlier?
HCV serologies (antibodies) with HCV RNA PCR: perform at 12-18 months: if positive at 12 months, then need to for sure repeat at 18 months since maternal abs can persist until then (one study showed 95% of uninfected infants will be seronegative by 12 mo)-can perform the test earlier (no earlier than 2 mo) if there is significant parental anxiety or if there is concern that the infant will be lost to follow up - in this case, would do HCV RNA PCR
141
A child's first HCV RNA test is positive. What are the next steps?
Will require HCV RNA PCR and liver enzymes q6mo to determine whether chronic infection or spontaneous clearance will occur.-if becomes chronic HCV, refer to peds GI and ID
142
What 2 vaccines would you consider giving to a child born to a woman with HCV?
1. Hepatitis A2. Hepatitis B
143
Which of the following statements is false:a. Most reported infections acquired in ambulatory care have been the result of procedures performed thereb. Hep B and C viruses have been transmitted by contamination of multi-dose vials or due to use of same physical space to prepare/dismantle and dispose of injection equipmentc. In the 1980s, a small proportion of all cases of measles in the US were acquired in ambulatory care settingsd. There have been reports of transmission of TB from doctors to patients in ambulatory care
C: a LARGE proportion of all cases of measles in the US were acquired in ambulatory care settings
144
How many resp infections can young children have in a year?-gastrointestinal infections?
-Resp: 4-10/yr-GI: up to 4/yr
145
What are factors that influence the risk of infection transmission in a pediatric office?-examples of infectious organisms
1. Young children with snot, diarrhea in diapers, open infected wounds2. Organisms that can survive on patient equipment3. Organisms with low infective dose 4. Presence of children with immunosuppression**ex. resp viruses and rotaviruses have low infective doses and persist for a long time on inanimate objects
146
What 2 organisms can survive on stethscope diaphragms?
1. MRSA2. RSV
147
How long do patients have to be isolated for the following:-enteroviral infection-gastroenteritis-hepatitis (A, E)-influenza-measles-bacterial-mumps-pertussis-rubella-sars-varicella-zoster
**Duration of illness:-enteroviral -gastroenteritis (or until infectious cause ruled out)-influenza-viral resp tract infection**Hepatitis: until 7 days after onset of hep A or until infection ruled out**Measles: until 4 days after onset of rash **Bacterial: until 24 hr of appropriate abx received**Mumps: until 9 days after onset of parotitis**Pertussis: until 5 days of appropriate abx received**Rubella: to 7 days after onset of rash**SARS: 10 days after resolution of fever**Varicella and zoster: until lesions crushes
148
Which organisms are transmitted via airborne? (5)
1. Varicella2. Zoster3. TB4. Measles5. Smallpox
149
For a child who is coughing and sneezing, when are smasks required by healthcare professionals?
When they will be within 2 m of the patient-prevents inhalation of organisms
150
Which organisms require just droplet precautions and why not droplet/contact precautions? (3)
1. H. flu2. N. meningitidis3. Bordatella pertussis*Can be transmitted by large droplets expelled during coughing or sneezing and thus, masks are recommended. However, they are very fragile and do not survive in the environment or on hands and thus contact precaution is not required.
151
Which group of organisms require droplet & contact precautions and why do they need both?
Respiratory viruses!Need both because they can survive long enough on surfaces to be picked up on hands of patients or personnel who then touch their mucous membranes1. RSV2. Influenza3. Parainfluenza4. Rhinovirus5. Adenovirus6. SARS
152
Why are N95 masks rarely needed in pediatricians' offices? (2)
1. Personnel should already be immune to varicella and measles via vaccines2. TB in children is rarely contagious
153
In infection control, what is the definition of the following and give an example of each:1. Critical items2. Semicritical items3. Noncritical items4. Environmental surfaces
1. Critical items: items that enter sterile tissue-ex. needle2. Semicritical items: items that contact mucous membranes or nonintact skin but do not enter tissues-ex. speculum, laryngoscope3. Noncritical items: items that touch only intact skin-ex. stethoscope, blood pressure cuff4. Environmental surfaces-ex. doorknobs, table tops
154
Which of the following is false:a. There is good evidence that incorporating antiseptics into plastic toys by toy companies decreases risk of infectionb. The AAP recommends cleaning of toys in officesc. Soft toys are unsuitable for doctors' waiting rooms due to difficulty disinfecting themd. Alcohol-based hand rinses and gels have been shown to be more effective than soap and water for removing microorganisms from hands
A! There is NO evidence that incorporating antiseptics into plastic toys impacts infection transmission
155
Which of the following is false:a. Carpeting should be avoided in examination and waiting roomsb. Ventilation for new or renovated medical offices should provide a minimum of six air exchanges per hourc. Parents should be advised to inform the receptionist on arrival if they think their child has a contagious illness d. immunocompromised children can wait in the same waiting room as other childrene. A child with symptomatic infection should be placed into an exam room immediately
D! Immunocompromized children need protection from exposure to patients with transmissible infections and should be placed into an exam room IMMEDIATELY upon arrival!
156
What are the recommendations on the presence of toys in the waiting room of an office in terms of infection control policy?
1. Sharing of toys by infants and children should be minimized-consider removing toys from waiting rooms unless use can be supervised and cleaning is feasible2. Ask parents to bring the child's personal toys for individual play and avoid sharing3. If toys are provided, avoid ones with small pieces and crevices, stuffed/plush/fabric toys which are difficult to clean4. Used toys should be removed from circulation until cleaned5. Consider use of disposable books and disposable toys designed for individual child play6. Children who are old enough to have appropriate hand hygiene and handling of resp secretions may share toys.
157
For infection control in an office setting, what are some methods to minimize contact between children with contagious illnesses and well children?
1. Schedule visits for different times of the day or separate time periods reserved for drop in visits and for routine appointments2. Children with contagious symptoms should be immediately brought to an exam room to wait instead of in the waiting room
158
Which of the following is false: a. Gloves are needed for administering vaccinesb. Gloves are not needed for routine child care such as wiping nose or changing diaper if there is no direct hand contaminationc. Gloves should be worn if health care worker has open lesions on the handsd. Spills of blood should be cleaned with detergent followed by bleach
A! Gloves are not needed for administering vaccines-gloves are only needed if you are anticipating direct contact with blood or bodily fluids
159
How often should environmental items (ie. exam tables, pt chairs, sinks, door knobs, etc) be cleaned in an office setting?
Daily
160
How should toys be cleaned in an office setting to prevent infection?
Disinfect with 1:100 bleach solution, wash with soap and water and air dry. OR can put in dishwasher
161
Which of the following statements regarding infectino control in an office setting is false:a. Antiseptic cleansing solutions should be discarded after 28 days of useb. Multidose medication vials should be avoidedc. After a patient with TB has left an exam room, the room should not be used until 70 mins later (if air exchange/hr is 6) or not for the rest of the day (if air exchange is unknown) to allow the air to be filteredd. For SARS or avian influenza, health professionals do not need to wear an N95 mask
D! Current recommendation is to wear an N95 mask with these patients
162
Are colds/minor resp infections criteria for exclusion from work? Which common infections do exclude you from direct patient care until symptoms resolve?
No but you should not have direct contact with high risk patients and you should wear a mask!***Conditions that exclude you from direct patient care:-gastroenteritis-conjunctivitis-Hep A (until one week after onset of jaundice)-influenza-varicella
163
In the literature, how many case reports of HBV & HCV transmission following needle stick injuries in the community (ie. not occupational needle stick injury) ? What about HIV?
Just 1 case report each of HBV and HCV transmission. There is no reported transmission of HIV transmission.
164
What is the risk of acquiring HBV from an occupational needle stick injury when the source if hep B surface antigen positive?-how long can HBV survive for in discarded needles?
2-40% depending on the source's level of viremia-can be transmitted by a TINY amount of blood-can survive for up to 1 wk in discarded needles
165
A 3 year old child comes to your office immediately with a needle stick injury after playing with a needle he found in the playground. What is your first management step and what investigations should you order?
1. Clean the wound thoroughly with soap and water ASAP and do not squeeze the wound to induce bleeding2. Check child's immunization status for HBV and tetanus3. Tetanus vaccine, with or without tetanus immunoglobulin, should be given if indicated4. Inquire about circumstances of injury: date and time, where the needle was found, type of needle, was a syringe attached, visible blood in needle or syringe, did injury cause bleeding, was previous user of the needle known) 5. Send blood for baseline HBV, HIV, HCV status-if antiretrovirals are being considered: CBC + diff, liver enzymes, renal function tests6. If the user of the needle is known, find out their RFs for blood borne viruses and test if possible
166
What is the risk of acquiring HCV as a result of an occupational needle stick injury when the source was infected?-management?
3-10%HCV is fragile and unlikely to survive in the environment-management: unfortunately no postexposure prophylaxis-order Hep C abx and HCV RNA PCR
167
What is the treatment for chronic Hep C infection?
1. Alpha interferon2. Ribavarin
168
What is the risk of acquisition of HIV from an occupational needle stick injury from a known HIV seropositive source?-what factors influence the risk? (4)
0.2-0.5%-factors:1. size of needle2. depth of penetration3. whether blood was injected4. level of viral inoculum in the blood injected***most reported cases of transmitted HIV via needle stick injury occurred within seconds or minutes after the needle was withdrawn from source patient
169
Why is there a difference in rate of transmission of HBV/HCV/HIV from needle stick injuries in community vs. occupational injuries?(4)
1. Injury does not occur immediately after needle use2. Needle rarely contains fresh blood3. Any virus present has been exposed to environmental temps and drying4. Injuries are superficial
170
In occupational needle stick exposures, zidovudine prophylaxis was shown to reduce the risk of HIV transmission from a positive source by what percentage?
80%-use of 2 drugs or 3 drugs including zidovudine is controversial but it is presumed that more drugs will result in more suppression (but adherence is an issue since more meds are less well tolerated by patients)
171
A 3 year old child comes to your office with a needle stick injury after playing with a needle he found in the playground. After taking a history and drawing initial bloodwork, mom tells you that child is known to be HBV ab or HBsAg-positive. What is your next management step for possible HBV prophylaxis?
No action required!
172
A 3 year old child comes to your office with a needle stick injury after playing with a needle he found in the playground. After taking a history and drawing initial bloodwork, mom tells you that child has not been fully vaccinated against HBV. What are your next management steps for possible HBV prophylaxis?-if anti-HBs ab and HBsAg are negative, what then?-if anti-HBs or HBsAg positive, what then?
1. Test for anti-HBs abs and HBsAG. 2. If results are not available within 48 hr, give HBIG immediately (within 48 hr of injury but up to 7 days post, 0.06 ml/kg IM) and HBV vaccine immediately.-if anti-HBs ab AND HBsAg-negative, complete vaccine series.-if anti-HBs positive but HBsAg negative, discontinue vaccine series as patient is immune-if HBsAg positive, arrange f/u (confirms HBV infection)
173
A 3 year old child comes to your office with a needle stick injury after playing with a needle he found in the playground. After taking a history and drawing initial bloodwork, mom tells you that child has been fully vaccinated against HBV. What are your next management steps for possible HBV prophylaxis?-if anti-HBs ab positive?-negative?
1. Test for anti-HBs ab. 2. If results are not available in 48 h, give dose of HBV vaccine.-if anti-Hb abs positive, no further action required-if anti-HBs abs negative, test for HBsAg-if HBsAg negative, give HBIG and dose of HBV vaccine-if HBsAg positive, arrange appropriate f/u
174
In community needle stick injuries, when should antiretroviral prophylaxis for HIV be recommended? (3)-ie. what is considered high risk?
High risk cases:1. Source considered likely to have HIV (source unknown but presumed high prevalence of HIV in IVDU in the region or source known to have HIV)2. Incident involved needle and syringe (blood could get pushed into the skin by the syringe)3. Blood was injected (into skin, mouth, eyes) **in situations of low risk, should still consider prophylaxis. Discuss with parents/child and weight benefits and risks of antiretroviral therapy x 4 wks
175
If antiretroviral prophylaxis is indicated for a community needle stick injury:-when should be it started?-is there a time limit for when it can be started?-what if parents are undecided?
Should be started ASAP, within 1-4 hrs of injury is ideal.-prophylaxis is not recommended if it cannot be initated within 72 hrs of injury-if parents are undecided, should tell them that it is preferable to start prophylaxis immediately and then discontinue if they wish because starting later may not be beneficial anymore
176
Which antiretroviral agents should be used for occupational and community needle stick injuries if postexposure prophylaxis is indicated?-low risk-high risk-duration of treatment-monitoring while on treatment?
-If low risk: 2 nucleoside reverse transcriptase inhibitors (zidovudine + lamivudine)-If high risk: 2 NRTIs + protease inhibitor (zidovudine + lamivudine + lopinavir/ritonavir)-duration of treatment: 28 days-no longterm or serious detrimental effects but may cause nausea/discomfort-on initial visit, prescribe only 3 d course and get f/u on 3rd day to assess for adherence, side effects. If the decision is made to continue prophylaxis, then prescribe for 28 d and f/u at 2, 4, 6 wks for CBC, liver enzymes, renal function test
177
What is the timing of HBV vaccine?
1 dose at time 0, 2nd dose at 1 mo, 3rd dose at 6 mo for lifelong immunity
178
What is the f/u testing required to r/o HIV/HCV/HBV infection for a needle stick injury in the community?
-6 wks: test for anti HIV ab-3 mo: test for anti HIV ab and anti-HCV ab-6 mo: test for anti HIV ab, anti HCV ab, anti-HBsAg ab
179
What are the 5 important factors that should be taken into account when creating a screening program?
1. Sensitivity and specificity of the diagnostic test2. Acceptability and feasibility of the diagnostic test3. Benefit of early detection (ie. there is a treatment that when started early provide benefit)4. Disadvantages of testing5. Prevalence of disease
180
What is the current approach to diagnosing HIV infection?
First test for HIV antibodies using enzyme immunoassay (ELISA). If positive, then confirm presence of HIV antibodies by western blot.
181
Which HIV does western blot detect?-what are the possible causes of an indeterminate western blot (4)
Only detects abs to HIV-1 only-indeterminate WB: 1. early infectino2. infection with HIV-2 (west africa)3. waning maternal abs in an infant4. false-positive result
182
Which of the following is false?a. If a rapid HIV test is positive, this confirms that the patient has HIV.b. Rapid HIV testing tests for antibodies and provides a result in less than 30 minutes.c. Rapid HIV testing has acceptable sensitivity and specificity to be used as a screend. Rapid HIV testing can be used to screen women with no prenatal care or high-risk women in late pregnancy or during labor
A! If a rapid HIV test is positive, you MUST confirm with standard serology tests (ie. ELISA, then Western Blot)
183
What is the current recommendation on HIV screening during pregnancy?
Routine prenatal testing for HIV should be recommended to all pregnant women-need pre and post test counselling
184
What is the rate of perinatal HIV transmission?-what about if antiretroviral therapy during pregnancy and intrapartum and newborn AZT (ie. zidovudine) takes place?
25%-a study found that if pregnant woman received antiretroviral therapy and there is intrapartum and newborn AZT, risk of transmission is <2%
185
What is the most important factor in the risk of perinatal transmission of HIV?
Maternal viral load -women with undetectable viral loads rarely transmit HIV
186
What is the rate of HIV transmission per year of breastfeeding?
9%-thus, HIV is a contraindication to breastfeeding regardless of maternal viral load or antiretroviral therapy
187
What is the recommendation for method of delivery in a pregnant woman with HIV?-cut-off for viral load for when C-section risks outweigh benefits of prevention of HIV transmission?
Elective C-section before onset of labor and ROM -cut off: American college of Obs-Gyne recommends that women with viral load < 1000 copies/ml of HIV RNA can be delivered vaginally. Canadian consensus guidelines still suggest that either elective C-section OR vaginal delivery is appropriate
188
A pregnant woman presents in labor with no prenatal care. She is an IV drug user and has multiple sexual partners. What is your management?
Perform expedited HIV serology on the mom with informed consent during labor or after delivery and then perform expedited HIV serology on the newborn with appropriate consent.
189
Why does congenital rubella syndrome continue to occur in Canada? (3)
1. Rubella virus is brouught into the community by travellers2. Pregnant women with vaccine failure or failure to be immunized then catch Rubella-failure to be immunized: because they are missed, refuse the vaccine or come from countries where the routine immunization program only includes the monovalent measles vaccine rather than MMR
190
Which of the following statements is false:a. Almost 100% of people immunized with rubella vaccine seroconvertb. Failure of one dose of rubella vaccine to protect against disease occurs in up to 10% of casesc. Vaccine failure is predicted to continue in the future since Canadian children only receive 1 dose of MMR vaccined. Infection in a previously immune mother is rare
C = vaccine failure is predicted to be less common in the future since the majority of Canadian children receive 2 doses of the MMR vaccine
191
What are some strategies to reduce congenital rubella syndrome?
1. Identify and immunize susceptible women of childbearing age:-if a woman of child bearing age is new to Canada, most likely received just the monovalent measles vaccine and thus should be given the rubella vaccine (unless they have documented immunity or it is clear they have received a rubella containing vaccine in the past)-do NOT wait to check serostatus before immunizing since this might be a missed opportunity to vaccinate before pregnancy2. In pregnant women who have no previous documented rubella immunization or rubella seropositivity, send blood for rubella serologies. If seronegative, give rubella vaccine postpartum**No recommendation currently to screen previously rubella-immunized women for rubella serologies to document seropositivity
192
What lab testing should be done for a pregnant woman with suspected rubella?
Rubella IgG avidity (accumulated strength of multiple binding interactions such as between a protein receptor and its ligand) testing: helps differentiate between primary infection (with a high risk of CRS) from past infection (low risk of CRS)
193
A patient presents to your office and you suspect rubella infection. What are the appropriate lab investigations to confirm your diagnosis? (3)
1. Rubella IgM serology--> in Canada where there is a low prevalence of rubella, without a travel history to endemic areas, IgM serology has a low positive predictive value for rubella. THUS...need to order:2. Paired acute and convalescent IgG serology: look for a fourfold or greater rise in titre3. Rubella virus detection
194
What are the clinical features of congenital rubella syndrome?
***Think small head, eyes, ears, heart, liver/spleen, platelets and bone!!!!! The keys are BONE and HEART1. Microcephaly2. Cataracts3. Glaucoma4. Pigmentary retinopathy5. Hearing impairment6. PDA7. Hepatosplenomegaly8. Thrombocytopenia (hence blueberry muffin rash)9. Radiolucent bone densities
195
How to distinguish between congenital CMV infection and congenital rubella infection?
Both have microcephaly, hepatosplenomegaly, IUGR, thrombocytopenia, hearing loss, cataracts (blueberry muffin rash)Congenital CMV: periventricular calcifications leading to SEIZURES-Cmv = C-zuresCongenital Rubella: CARDIAC defects (PDA) and radiolucent BONE densities-RuBella = BONE
196
What is a possible complication of rubella vaccine in nonimmune women?-if patient is worried about this possible complication, what should you tell them?
Transient acute arthritis or arthalgia = 5-10% chance-if the patient is reluctant, tell them that acute and persistent forms of arthritis after natural rubella infection is more common (up to 30% with recurrent joint manifestations for up to 2 years)
197
A woman has just been immunized for MMR. How long should she wait until she becomes pregnant?
28 days after vaccine since it is live.
198
What is the ideal interval between administration of inactivated vaccines to optimize vaccination status for a pretransplant patient and the timing of the transplant itself?
At least 2 weeks to allow for an adequate immune response
199
When is the ideal interval between adminsitration of a live vaccine to optimize vaccination status for a pretransplant patient and the timing of the transplant itself?
At least 4 weeks
200
What are the goals for the pre-organ transplant period for patients (2)?
1. Optimize vaccines in transplant candidate and transplant candidate's family members2. Identify acute, chronic or latent infections in the transplant candidate and in prospective living donors
201
What infections can be expected in the first month after transplant?
> 95% of infections in this period are similar to infections in nonimmunosuppressed patients who have undergone a comparable surgical procedure-the remainder 5% are due to infection present in the recipient before transplant or infection being transmitted by allograft
202
What infections can be expected in the 1-6 months post-transplant?-2 types
1. Viral pathogens (primary aka from the donor, reactivation of latent pathogens or reinfection with a new strain of the virus)-ex. CMV, EBV, HHV6, Hep B + C2. Bacterial/fungal-Listeria, Aspergillus, Pneumocystic jirovecii
203
What infections can be expected more than 6 month post-transplant?
-Pts on maintenance immunosuppression and good allograft function: at same risk of community-acquired infections as healthy children-Pts with poor post-transplant outcomes are at high risk for recurrent infections related to mechanical or anatomical problems AND opportunistic infections (Listeria, Pneumocystis, cryptococcus, nocardia)
204
What is the management of a febrile post-transplant patient with defined focus of infection?
At minimum, should have a CBC/diff + blood culture-other investigations depend on clinical focus and timing of presentation after transplant
205
What is the management of a febrile post-transplant patient with no obvious focus of infection?
Minimum workup should include CBC/diff + blood culture + urine culture-liase with transplant team
206
For post-transplant patients, when is ideal timing for post-transplant immunizations?
Do NOT administer within the first 6-12 months following transplant with the exception of seasonal inactivated influenza vaccine (do not give earlier than one month post transplant)
207
What is the recommendation for pneumococcal vaccines for post transplant patients?
Given the high risk of invasive pneumococcal disease, recommend: 13 valent pneumococcal conjugate followed in 2 months by the 23 valent vaccine
208
What vaccinations are contraindicated in post-transplant patients?
Live-attenuated vaccines-MMR-Varicella-Rotavirus
209
What screening serologies should routinely be completed for transplant candidates (9)?
1. HIV 1 and 2 2. Hepatitis A, B, C, D3. HTLV 1 and 2 (human T-lymphotropic virus)4. CMV5. EBV6. HSV7. VZV8. Toxoplasmosis (in heart or heart-lung candidates)9. Measles, Mumps, Rubella to check for titres
210
What is acute otitis externa?
Diffuse inflammation of the external ear canal
211
What is the pathophysiology of acute otitis externa?-risk factors for AOE? (8)
Prolonged ear canal weakness causes skin desquamation and microscopic fissures that provide portal of entry for infecting organisms-Risk factors:1. Swimming = prolonged ear canal wetness2. Immunocompromised3. Trauma4. Foreign body in ear5. Using hearing aid6. Derm condition7. Chronic otorrhea8. Tight head scarf
212
What are clinical features of acute otitis externa? (3 categories)
1. Onset: rapid (generally within 48 h)2. Symptoms of ear canal inflammation: otalgia, itching or fullness with or without hearing loss or jaw pain3. Signs of ear canal inflammation: tenderness of tragus when pushed, tenderness of pinna when pulled, diffuse ear canal edema/erythema with or without otorrhea, regional lymphadenitis, cellulitis of pinna or adjacent skin
213
What are the two most common infectious organisms causing acute otitis externa?
1. Staph aureus2. Pseudomonas aeruginosa(3. Polymicrobial)
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When should you swab the ear to isolate an organism in acute otitis externa?
Do in cases that are unresponsive to treatment or are severe
215
In which cases should ototoxic topical agents (gentamicin or neomycin) be avoided to treat acute otitis externa? (3)
1. Perforated tympanic membrane2. Can't see tympanic membrane3. Presence of tympanostomy tubes
216
What is first-line therapy for treating mild-to-moderate acute otitis externa?
Topical antibiotic +/- topical steroids x 7-10 days (evidence is not great for either one alone or combined so do what you want)
217
What is first-line therapy for treating severe acute otitis externa?
Systemic antibiotics that cover S aureus and P aeruginosa
218
What is the evidence for efficacy of aural toileting, wick therapy,and ear candling for treating acute otitis externa?
No randomized controlled trials examining effectiveness of aural toileting (cleaning out wax and debris from ear with little cleaning stick) and wick therapy (piece of gauze soaked in antibiotic drops). Ear candling (inserting a hollow candle into the ear and lighting the flame on the other end) has been shown to have no efficacy and can be harmful!!!
219
With appropriate therapy, when can clinical improvement be expected in acute otitis externa?
Within 48-72 hrs of therapy-full response can take up to a week
220
If a patient does not respond to appropriate topical antibiotic therapy for acute otitis externa, what should be ruled out? (4)
1. Obstruction2. Foreign body3. Non-adherence to therapy4. Alternative diagnosis: contact dermatitis from nickel, viral or fungal infection, antimicrobial resistance
221
What is malignant otitis externa?-populations at risk-diagnosis-management
Malignant otitis externa: invasive infection of cartilage and bone of ear canal -can have facial nerve palsy and significant pain-diagnose with CT or MRI-treat with aggressive debridement and systemic antibiotics
222
How can acute otitis externa be prevented?
Keep water out of the ears!-ear plugs or removing water from ears after swimming-avoid cotton swabs because they impact cerumen
223
Why is the risk of bacterial contamination of platelets greater than for red cells?
Platelets are stored at room temperature
224
What is the estimated risk of contracting the following from blood transfusion in Canada?-HIV-Hep C-Hep B-bacteria
HIV: 1 in 8 millionHep C: 1 in 5 millionHep B: 1 in 1 million Bacteria: 1 in 100,000 in platelets
225
Which infants are at highest risk of acquiring HSV?
Infants born to mothers who have a first-episode primary infection at the time of delivery since the mother had no pre-existing neutralizing antibodies to transmit to the baby through placenta-remember that most newly acquired cases are asymptomatic
226
What steps may reduce risk of neonatal HSV transmission during pregnancy or at time of delivery?
1. Acyclovir from 36 wks GA until delivery (no clear evidence on whether this reduces risk)2. Delivery by elective C-section in woman with active HSV lesions at delivery3. Avoid procedures that may break baby's skin: forceps, vaccuum, fetal scalp monitoring
227
What are the 3 categories of HSV infections?
1. Disseminated2. Localized CNS3. Skin, eye and mucous membrane
228
When should HSV be considered as a diagnosis in neonates?
Fever with irritability, seizures, liver dysfunction, or abnormal CSF fluid**Remember that in most cases, there is no known history of maternal HSV and infant has no skin vesicles!
229
What is the dose of acyclovir for treatment of neonatal HSV? What is the duration of treatment?
Dose: 60 mg/kg/day or 20 mg/kg/dose IV q8hDuration: -SEM: 14 days IV-CNS/disseminated: 21 days minimum IV(Oral ACV has limited bioavailability thus IV is required)
230
What is the definitive diagnostic test for non-CNS HSV?
Isolation of HSV by viral culture (from oropharynx, nasopharyn, skin lesions, mucous membranes)
231
What is the definitive diagnostic test for CNS HSV?
HSV PCR (more sensitive than culture)
232
Why is infant serology not useful for diagnosing neonatal HSV infection?
1. Transplacental IgG antibodies cannot be differentiated from IgG produced by baby2. Production of antibodies is impaired in severely affected infants3. Commercially available assays for HSV IgM abs are of limited reliability
233
What are two side effects of acyclovir?
1. Nephrotoxicity2. Neutropenia
234
What is the management of ocular HSV in neonates?
1. IV acyclovir x 14 days2. Topical 1% trifluridine3. Ophtho consult
235
What follow-up should infants with neonatal HSV infections have?
Because of potential for neurological sequelae, f/u should include:1. Neurodevelopment2. Ophtho3. Audiology
236
When a diagnosis of neonatal HSV is suspected, what diagnostic investigations should be ordered? (3)
1. Swabs of vesicular lesions and mucous membranes for culture or PCR2. CSF HSV PCR3. Liver enzymes to assess for disseminated HSV
237
When evaluating for neonatal HSV infection in exposed asymptomatic infants, what diagnostic investigation should be ordered? (1)
1. Mucous membrane swabs from mouth, nasopharynx and conjunctivae at least 24 hrs after delivery (so that maternal HSV virus on baby's skin from delivery has time to clear)
238
How long does it take for antibodies to HSV to develop following an infection?
Approximately 3 weeks
239
What is the management for an infant delivered by C-section before ROM to a mother with presumed first-episode primary or first-episode nonprimary HSV infection at delivery?
Risk of NHSV is very low. If baby is well:1. Swab the baby's mucous membranes at > 24 hrs of age2. If swabs are negative, then baby can be discharged home3. If swabs are positive, then the infant is managed as a case of neonatal HSV(Some experts recommending doing CSF analysis as well)
240
What is the management for an infant delivered by SVD or C-section after ROM to a mother with presumed first-episode primary or first-episode nonprimary HSV infection at time of delivery?
1. Test mom for HSV-1 and HSV-2 antibodies to figure out if she has primary (no prior HSV antibodies), nonprimary (HSV antibodies present but to the other type of HSV), or recurrent (antibodies present)2. Swab baby's mucous membranes and start acyclovir (controversial whether to do this at birth with risk of surface contamination or at 24 hr of life)3. If swabs are positive, need to obtain CSF PCR to r/o CNS HSV4. If swabs are negative and mom's serologies show she has recurrent HSV, then d/c acyclovir5. If swabs are negative and mom has primary HSV or serology testing is not available, baby needs acyclovir x 10 days
241
What is the management for an infant born by C-section to a mother with recurrent HSV at delivery?
1. Swab mucous membranes at 24 hrs of life2. If positive, treat as neonatal HSV3. If negative, d/c home
242
What is the management for an infant born by SVD to a mom with recurrent HSV at delivery?
1. Swab mucous membranes at 24 hrs2. If positive, treat as neonatal HSV3. If negative, d/c home**This is because baby is presumed to have HSV antibodies from transplacental transfer
243
What is the management of asymptomatic infants whose mothers have no active lesions at delivery?
Does not swabs or acyclovir therapy
244
Name 4 clinical scenarios in which you should consider neonatal HSV in the differential diagnosis?
1. Infants started on IV antibiotics for suspected sepsis (especially infants with seizure or yielding abnormal CSF) who do not improve rapidly and have negative bacterial cultures at 24 hr incubation2. Infants admitted with pneumonia who do not improve after 24 hr on antibiotics3. Infants with unexplained bleeding or coagulopathy4. Infants started on IV antibiotics for suspected sepsis who are found to have unexplained hepatitis
245
What is the management of HSV CNS disease?
1. IV acyclovir x 21 days minimum2. Repeat CSF sampling near the end of 21-day course of therapy: if PCR remains positive, treatment should be extended with weekly CSF sampling and acyclovir stopped when negative PCR is obtained3. Suppressive therapy oral acyclovir x 6 months should be given to infants with CNS disease (double-blind RCT showing benefit in neurodev outcome)
246
For infants on suppressive oral acyclovir treatment, what surveillance should they have?
Monthly CBC, BUN, Cr to rule out neutropenia and nephrotoxicity
247
What are 4 contraindications to LP?
1. Coagulopathy2. Cutaneous lesions at the proposed puncture site3. Signs of herniation4. Unstable clinical status
248
What empiric antibiotics should be started in a child with immunodeficiency suspected of having meningitis?
1. Vancomycin (for cephalosporin-resistant strep pneumo)2. Ceftriaxone (for penicillin-resistant strep pneumo, Neisseria meningitidis, H flu)3. Ampicillin (for Listeria which immunodeficiency people are at risk for contracting)
249
What are 2 early complications associated with acute meningitis?
1. SIADH2. Increased ICP
250
What is the antibiotic of choice for treatment of GBS meningitis?
Penicillin G or ampicillin & add gentamicin for the first 5-7 days or until CSF sterility confirmed
251
What is the treatment of choice for Hib meningitis?-antibiotic-adjuvant therapy
1. Ampicillin (for amp sensitive) or Ceftriaxone (for amp resistant)2. Steroids = evidence that this decreases hearing loss if administered just before or with initial abx therapy
252
What is the current recommendation for use of steroids in meningitis?
When a bacterial meningitis is suspected, can give dexamethasone 0.6 mg/kg/d divided q6h immediately before or within 30 minutes after the first dose of antibiotics.-If Strep pneumo or Hib is cultured, continue the steroids for total of 2 days. -If neither of these organisms is cultured, then d/c steroids
253
When to consider repeat CSF sampling in a child being treated for meningitis (3)?
1. If a child does not clinically improve with initial therapy2. GBS meningitis (recommended by some experts) 3. Gram negative enteric pathogen meningitis (E. coli) **Repeat at 24-48 hrs after therapy
254
When is CNS imaging recommended for bacterial meningitis (2)?
1. Failure of sterilization of CSF2. Neurological symptoms develop
255
What is the recommended length of antibiotic therapy for meningitis:-Strep pneumo-Hib-Neisseria-GBS
Neisseria 5-7 dHib - 7-10 dStrep pneumo - 10-14 dGBS - 14-21 d
256
When should audiology assessment occur for children with meningitis?
Prior to discharge or within one month of discharge
257
4CMenB vaccine (to cover Neisseria meningitidis serotype B) should be offered to which patients (3)?
1. Asplenia/hyposplenism2. Congenital immunodeficiencies: complement deficiency, properdin deficiency3. Patients with previous episode of invasive disease4. Lab workers
258
What is the most common side effect of 4CMenB vaccine?
Fever lasting >24 hrs in 65% of immunized (compared to 32% from routine vaccines)
259
Why do infants and young children rarely develop symptoms from C. difficile colonization (2)?
Diarrheal disease in prev healthy infants < 1 yo is not likely due to C. diff:1. Immature surface receptors on bowel for C. diff (so cannot bind and cause inflammation)2. Protected by maternal antibodies acquired transplacentally or in breast milk***Asymptomatic carriage in 15-63% of neonates, 3-33% of infants and toddlers < 2 yo, 8% of children > 2 yo
260
What are 4 risk factors for development of pediatric C. diff infection?
1. Prolonged hospital stay2. Older age3. Recent antibiotic use (within 12 wks)4. Immunosuppression-especially impaired humoral immune response (HIV patients, hypogammaglobulinemia)
261
Why does chemotherapy increase risk of C. diff infection?
1. Immunosuppression2. Changes in the gut mucosa
262
What is the significance of the NAP1 strain of C. diff?
Fluoroquinolone resistant, may be causing disease in younger infants
263
What are 2 pathophysiological features of C. diff that make it so resilient?
Spores are:1. heat resistant2. acid resistance (pass easily through stomach to small bowel)
264
What are the two toxins produced by C. diff and what are their effects?
1. Toxin A - enterotoxin-bind to intestinal mucosal cells, disrupt neuronal function and cause aberrant release of calcium2. Toxin B - cytotoxic-affect neutrophils, macrophages, mast cells and induce inflammatory mediator relase Overall effect: intestinal fluid secretion, mucosal damage and interstitial inflammation
265
What is required for the diagnosis of C. diff infection (2)?
1. Presence of symptoms (watery or bloody diarrhea)2. Stool test result that is positive for C. diff TOXINs OR Colonoscopy findings demonstrating pseudomembranous colitis
266
How do you classify mild, moderate and severe C. diff infections?
Mild - watery or bloody diarrhea (< 4 per day), low grade fever, mild abdo painModerate - like mild but > 4 per daySevere - systemic toxicity (high grade fever, rigors)Severe + complications - systemic toxicity + shock, peritonitis, ileus or megacolon
267
What are clinical features of pseudomembranous colitis?
Severe diarrhea, abdominal pain, fever, leukocytosis, systemic toxicity, stool with blood/mucous, toxic megacolon (increased risk of intestinal perforation)
268
Why is C. diff culture not useful for diagnosis of C. diff infection?
C. diff grows very slowly on culture; also does not give you information about colonization vs. invasive infection
269
What lab testing methods are recommended for C. diff infection diagnosis (2)?
1. Enzyme immunoassay for glutamate dehydrogenase (GDH) - present in almost all strains of C. diff including ones that don't produce toxin-use this for initial screen; then if positive, order...2. EIA for toxins A & B
270
What is the treatment for C. diff infections?-mild-moderate-severe-severe + complications
1. Mild: discontinue precipiating antibiotic, f/u and r/a2. Moderate (or mild not responding to abx d/c): -metronidazole 30 mg/kg/d div q6h PO x 10-14 d3. Severe: -Vancomycin 40 mg/kg/d div q6h PO x 10-14 d4. Severe + complications:-Vancomycin 40 mg/kg/d div q6h PO x 10-14 days PLUS-Metronidazole IV 30 mg/kg/d div q6h x 10-14 days (If complete ileus: consider adding rectal instillation of vancomycin)
271
What are some strategies to reduce spread of C. diff infection in hospitals (3)?
1. Hand hygiene (hand washing since alcohol-based hand hygiene products do not kill C. diff spores)2. Contact precautions until 48 hr symptom free3. Antibiotic stewardship
272
Should stools be re-tested for C. diff once a patient has been treated for C. diff infection to ensure clearance?
NO - stools often remain toxin-positive despite cure
273
Is there evidence to support probiotic use in C. diff infections?
Emerging data from meta analyses suggesting that probiotics may be beneficial in preventing CDI - no conclusive evidence yet-may have a role in preventing relapses in patients with recurrent CDI-use has been associated with fungemia in immunocompromised patients and in patients with CVLs
274
Why do you need to give vancomycin PO while you can give metronidazole PO or IV for C. diff infections?
Vancomycin MUST be PO in order to enter the gut to eradicate the C. diffMetronidazole can be given PO directly to the gut OR IV since enterohepatic circulation does deposit some of it into the gut
275
What is the evidence on stool transplant in C. diff infections?
Recent randomized trial showed duodenal infusion of donor feces was found to be more effective for treatment of CDI than standard vancomycin therapy-needs further research
276
Which population should receive annual influenza vaccination?
All children 6 months of age and older
277
Which component of the 2013/2014 influenza vaccine is different from the 2012/2013 vaccine?
Influenza B component since there was a change in the predominant circulating strain
278
What are the 2 types of influenza vaccines available in Canada?
1. IM Trivalent inactivated influenza vaccine (TIV)2. Intranasal live attenuated influenza vaccine (LAIV)
279
What age group can the intranasal live attenuated influenza vaccine be used in?
2 years old and older
280
Why is the LAIV not used in children younger than 2 years old?
Increased rate of wheezing 2-4 wks post-vaccination
281
Why is LAIV preferred over TIV for healthy children 2-17 years of age?
1. Greater efficacy2. Expected higher acceptance of intranasal administration vs. IM
282
Is LAIV recommended over TIV in children with chronic health conditions?
Insufficient evidence to recommend one over the other - either is acceptable
283
What are the most common side effect of LAIV?
Nasal congestion/rhinorrhea
284
What are the contraindications for LAIV (4)?
1. Immunocompromised2. Severe asthma (active wheezing, currently on steroids, medically attended wheezing within the last 7 days)3. Pregnancy4. Chronic ASA therapy (risk of Reye's syndrome)
285
If a patient is being treated for influenza with antivirals, how soon after can you give the LAIV?
48 hours after discontinuation of the anti-viral
286
If a patient received LAIV and then got the flu and needed antiviral therapy, what is the management plan with re-vaccination?
If the patient received LAIV within 2 weeks of starting the antiviral, needs to be revaccinated
287
Can LAIV be used in people with egg allergy?
LAIV has not yet been evaluated in egg allergy population - thus no recommendation to use yet. Egg allergy pts should still continue to receive the TIV
288
Which populations should receive the influenza vaccine (6)?
1. > 6 months of age2. Chronic medical conditions: cardiac, pulmonary, DM, cancer, immunodeficiency, morbid obesity, chronic conditions requiring ASA therapy3. All aboriginal children4. living in chronic care facilities5. all pregnant women6. all close contacts of children at risk: anyone coming into contact with children < 6 months, newborn, immunocompromised
289
What is the dose of TIV? LAIV?
TIV: 0.5 ml IMLAIV 0.2 ml (0.1 ml in each nostril)For the first year that a child younger than 9 years of age receives the flu vaccine, TWO DOSES at least 4 weeks apart are required!Children nine years of age and older and adults require only one dose each year
290
In patients with splenectomy, when is frequency of sepsis highest?
In first 3 years post splenectomy
291
What is the mortality rate of sepsis from encapsulated organisms in asplenic patients?
50-70%
292
What education should be given to patients with asplenia (5)?
1. Get vaccinated!2. Teach signs of sepsis and to seek medical attention with EVERY single fever3. MedicAlert bracelet4. When traveling, carry a note from doctor outlining diagnosis and management plan5. Increased risk of infection after animal bites (especially Capnocytophaga from dog bites) and thus need amoxi-clav if bitten
293
Which are used preferentially in asplenic patients: conjugate or polysaccharide vaccines?
Conjugate vaccines activate a superior immune response and thus are preferred.-especially in infants
294
What immunizations should asplenic patients receive to protect against pneumococcus?
Pneumococcus:1. Prevnar-13 (13 valent pneumococcal conjugated vaccine) -4 doses (at 2, 4, 6, 12 mo) to prime the immune system-THEN-2. Pneumovax (23-valent pneumococcal polysaccharide vaccine)-1 dose asap after 2 yo for supplemental protection with a booster in 5 years
295
What immunizations should asplenic patients receive to protect against meningococcus (2)?
1. Conjugate quadrivalent vacine (MCV4)-4 doses (at 2, 4, 6, 12 mo) as infants-revaccinate q5y-AND-2. 4CMenB (to protect against serotype B)
296
What immunizations should asplenic patients receive to protect against Hib?
Primary series of 3 doses at 2, 4, 6 months and booster at 18 mo
297
What organisms are targeted by vaccines given to asplenic patients?
1. Pneumococus2. Meningococcus3. Hib4. Influenza
298
Why is the influenza vaccine recommended for asplenic patients?
To decrease risk of secondary bacterial infections
299
In an asplenic patient traveling to less developed areas of the world, what additional precautions should they receive?
Increased risk for Salmonella infection and thus need to be immunizedAlso increased risk for severe malaria; thus should take prophylaxis
300
What vaccines should household contacts of asplenic patients receive?
All age-appropriate vaccines and yearly influenza vaccine
301
In elective splenectomy, when is the ideal timing for giving immunizations needed for asplenic patients?
At least 2 weeks prior to splenectomy
302
What organism is the most common cause of sepsis in children with asplenia?
Strep pneumo
303
What antibiotics are recommended for prophylaxis in children with asplenia/hyposplenia?-birth to 3 mo-3 mo to 5 yo-> 5 yo
1. Birth to 3 mo (concern for E coli and Klebsiella)-Amoxi-clav AND penicillin V 2. 3 mo-5 yo-Penicillin V OR amoxicillin3. > 5 yo-Pen V OR Amoxil
304
At what age should prophylactic antiobiotics be continued until in asplenic patients?
Red Book:-5 years of age and minimum of 1 year post splenectomyCPS: -5 years of age and minimum of 2 years post splenectomyIdeally, should remain on lifelong prophylaxis but there is a lot of controversy
305
What is the management of an asplenic child who has penicillin allergy?
1. Refer to allergist immediately to verify diagnosis and for challenge/desensitization as warranted2. Use erythromycin as alternative but this is much less successful at preventing invasive disease due to higher rates of pneumococcal resistance
306
Why is sepsis in individuals with asplenia or hyposplenia a medical emergency?-what abx should they receive?
They can die within several hours of fever onset despite appearing well initially-should receive ceftriaxone 100 mg/kg/dose-in regions with high-pen resistant pneumococcus, use ceftriaxone and vancomycin
307
What is the cross reactivity risk of a cephalosporin for a person with a penicillin allergy?
2%
308
What is the recommended duration of antibiotic therapy for:-AOM in children > 2 yo-Uncomplicated pneumonia-UTIs
-AOM: 5 days-Uncomplicated pneumonia: 7 days-UTIs: 7-14 days depending on extent of illness at presentation
309
What are 10 ways to promote antimicrobial stewardship?
1. Document clearly WHY you decided to use an antibiotic for a specific patient and schedule follow up instead of starting antibiotics for patients who are not very ill2. Detail suspected drug reaction to determine whether it's a true allergy3. Ensure minimum diagnostic criteria for diagnosis of UTI are met before starting abx (ie. increased WBC, leuks/nit)4. Use beta-lactams (ie. penicillin) for suspected Strep pneumo or GAS. Use clox or cephalexin for suspected Staph aureus5. Do not throat cx children with sore throat who have features of a cold. Positive GAS in this setting is almost always colonization instead of true infection6. Always use correct weight-based dose and optimize frequency and duration of antibiotic 7. Use ampicillin IV or oral amox for community-acquired pneumonia.8. Always get CXR for suspected pneumonia before starting abx.9. Children with wheezing almost never need abx because diagnosis is usually asthma or viral10. Know the typical bacteria that cause common outpatient infections (ie. skin and soft tissue infections are GAS or staph aureus)
310
In what circumstances should antiviral therapy be initiated even if illness onset was > 48 hrs ago? (3)
1. Illness is severe enough to require hospitalization2. Illness is progressive, severe or complicated regardless of previous health status3. Individuals in high risk for severe disease category (EXCEPT for children < 5 yo)
311
What are the major categories of patients who are predisposed to severe influenza illness?
1. Chronic medical disease (resp, cardiac, rheum, malignancy, renal, endo, hemoglobinopathy, immunosuppression, neuro)2. Children < 5 yo3. Children in homes or chronic care facilities4. Pregnant women 5. Children < 18 yo who are on chronic ASA6. Obesity with BMI > 40 7. First Nations, Inuit, and Metis children
312
What is the recommended length of antiviral treatment for influenza?
5 days but can be continued longer if clinically relevant
313
If a child cannot tolerate oral oseltamivir, what is the alternative?
Inhaled or IV zanamivir
314
In what 2 situations would zanamivir be preferred to oseltamivir?
1. Patients not responding to oseltamivir therapy2. Patients with illness despite oseltamivir prophylaxis
315
For patients with mild disease and no RFs other than age, what is the treatment for influenza?-< 1 yo-1-5 yo-> 5 yo
- < 1yo: Supportive care! (NAI not approved for children < 1 yo)-1-5 yo: for illness < 48 hrs, may consider antiviral treatment but not routinely required->5 yo: no routine antiviral therapy
316
For patients with mild influenza and risk factors for severe illness, what is the treatment?-< 1 yo-> 1 yo
- 1 yo: for illness < or > 48 hrs, treat with oseltamivir PO or inhaled zanamivir immediately
317
When is it most beneficial to start an antiviral for suspected influenza?
Within 48 hrs of onset of illness-otherwise healthy patients of any age with relatively mild, self-limited influenza are not likely to benefit from neuraminidase inhibitor therapy > 48 hr after illness onset
318
How is HPV transmitted? (2)
1. Sexually by direct epithelial to epithelial contact (even in absence of penetrative sexual intercourse)2. Vertical transmission
319
Which 2 HPV strains cause cervical/anal/penile/vulvar cancers?-which 2 HPV strains are responsible for genital warts?
-Cancer causing strains (high risk): HPV-16 & 18(think: teenagers like to use their genitals) -Genital warts causing strains (low risk): HPV-6 and -11
320
What is the most common STI in the world?-when does the highest rate of acquisition occur?
HPV-highest rate of acquisition occurs in first 5 years after onset of sexual activity -peak prevalence in adolescents and young adults < 25 yo
321
What are the risk factors for HPV infection? (7)
***Think of anything that increases your chance of having more sex1. Being female2. High number of sexual partners3. Early age of first intercourse4. Never being married5. Never being pregnant6. Immunosuppression7. Concurrent STIs changing the cervical microenvironment
322
What is the second most common malignancy affecting women? What is the bimodal peaks of incidence?
Cervical cancer: peaks among women in 40s and >70s
323
To be maximally effective at preventing long term complications of HPV infection, the vaccine must be given before when?
Before acquisition of infection ie. before onset of any sexual touching
324
What strains of HPV does Gardasil protect again?
HPV 6, 11, 16, 18
325
Which of the following is false:a. The HPV vaccine induces an excellent immunological response with > 99.5% mounting antibody levels above those induced by natural infectionb. These antibodies are present one month after completing the vaccine seriesc. Postvaccination, neutralizing antibodies have been demonstrated in cervical secretionsd. These antibodies are only sustained for 1 year
D! Antibodies are sustained over at least five years
326
How effective is the HPV vaccine in preventing cervical dysplastic lesions, vaginal and vulvar lesions, and genital warts?
98-100% in women who have not previously been exposed to HPV-44-55% in women who have been previously exposed or who did not finish the vaccine series
327
What is the timing of the administration of HPV vaccine? -not recommended for use in which group?
Given at 0, 2, 6 months -not recommended for use in pregnant women
328
What are the recommendations on who should receive the HPV vaccine?-which population in particular should be prioritized to receiving the HPV vaccine?
Administer routinely to all girls between 9-13 yo (hopefully before the onset of any sexual activity)-prioritize street-involved children and youth, foster care/group home youth since these children are at risk for earlier onset of sexual activity and missed immunization opportunities-advocate for funding and implementation of universall HPV vaccination programs
329
A 17 yo girl in your practice who has had previous genital warts and known HPV infection inquires about the HPV vaccine. Should you offer the vaccine? What other advice can you offer?
Yes, you should still offer because she may not have had infection with all of the HPV genotypes in the vaccine and may still benefit-educate her to continue to use condoms consistently and limit the number of sexual partners to reduce the acquisition of nonvaccine HPV genotypes and other STIs
330
A 17 yo male in your practice inquires about the HPV vaccine. What do you say? What other advice can you offer?
Efficacy of HPV vaccine has not yet been demonstrated in males and therefore cannot be recommended at this time BUT immunological data are convincing and some countries have already started vaccinating their boys. -educate him to continue to use condoms consistently and limit the number of sexual partners to reduce the acquisition of nonvaccine HPV genotypes and other STIs
331
What is the difference between primary vaccine failure vs. secondary vaccine failure?
Primary vaccine failure: immune response does not develop after a vaccine is givenSecondary vaccine failure: immune response develops after a vaccine is given but the immunity wanes over time
332
Which of the following is false:a. Breakthrough varicella disease is usually much less severe than naturally occuring varicellab. Breakthrough varicella is not associated with any complicationsc. Effectiveness of varicella vaccine wanes with time since vaccination, increasing risk of breakthrough at older agesd. Adolescents and adults with varicella infection have more severe complications than young children
B! breakthrough varicella is still associated with complications in about 5% of cases
333
What are the recommendations on what age the varicella vaccines should be given?
1st dose at 12-18 mo of age, 2nd dose at 4-6 yrs of age-if the patient is on a catch up schedule, the 2nd dose can be given 3 months after the first (in children <12) or 1 month after (in adolescents)-in Ontario, the 2nd dose is given as MMRV
334
Which of the following is false:a. People who have received varicella vaccine demonstrate an IgG to varicella zoster virusb. All pregnant women should be tested for varicella immunityc. Breakthrough varicella disease is often atypical with fewer/no vesiclesd. It is important that all health care workers be immune to varicella
A! People who have received varicella vaccination do not demonstrate IgG to varicella zoster virus! Only natural disease induces IgG varicella antibody that is measurable in commercial labs!
335
A patient comes to you and wants to know if they are immune to varicella. What is evidence of immunity to varicella?
1. IgG to VZV (confirms natural disease)2. Documentation of 2 doses of varicella vaccine (don't do serology!!)3. Lab confirmation of varicella or herpes zoster from a lesion4. Previous diagnosis of varicella disease or herpes zoster by a health care provider
336
How does lice spread?-what is required to make diagnosis of lice infestation?
Head to head contact-no clear evidence that sharing hats or pillow cases leads to transmission-lice infestation diagnosis: need to see an actual louse, not just nits
337
What is the bag contamination rate for urine culture?
60%
338
True or false: a negative urine culture via bag sample can effectively rule out UTI.
True!
339
Which of the following is least likely to cause a UTI in a previously healthy child not on antibiotics:a. enterococcusb. e colic. klebsiellad. enterobacter-what organism is more likely to be the etiology of a UTI in adolesnce?
Enterococcus: conflicting evidence on whether this truly causes UTI in a healthy child-staphylococcus saprophyticus
340
True or false: the risk of renal damage from acute pyelonephritis in children with normal kidneys is significant.
False!
341
What are the indications of a VCUG in UTI? (3)
1. Second febrile UTI2. Renal abnormality and obstruction3. Hydronephrosis on U/S
342
Name 3 risks of VCUG?
1. Infection2. Trauma3. Radiation
343
Name 2 diagnoses you can diagnose on VCUG?
1. Vesicourethral reflux2. Posterior urethral valves
344
Differentiate between nuclear cystogram and DMSA scan:-indications
-Nuclear cystogram: not useful to look at male anatomy, less radiation though, less readily available = reasonable to consider as the 1st test in girls and as follow up test in both genders because it's less radiation******-DMSA: looks at renal scarring and to diagnose pyelonephritis. Use when questioning the diagnosis of pyelonephritis/UTI. More radiation
345
People to involve on home IV team?
1. Doctor with expertise on home IV2. Primary care physician3. Infusion nurse4. Community home care service5. Surgeons6. Pharmacist with knowledge on home IV therapy7. Social worker8. Case worker
346
How long should the following be used for:-PIV-PICC-broviac or hickman tunnelled CVL-implanted port***Which of these have the lowest infection risk?
-PIV: 1-2 wks (1 in young child, 2 weeks in older child or teen and only if the drug is not prone to cause phlebitis or soft tissue damage if infiltration occurs-PICC: weks to months-Broviac or kickman: months to years (has multiple lumens for more than one drug or frequent blood tests)-implanted port: months to years (best for intermittent treatment, not good for long term daily access since skin will breakdown over the port)**Implanted port has the lowest infection risk since the vascular system is not exposed until catheter is accessed
347
In children who may need home IV, how do yo decide between sending them home with a peripheral intravenous or central venous line?
If IV therapy is > 2 weeks, need a central venous catheter (ie. PICC line, tunnelled central line or totally implanted ports)
348
How often should a patient be seen by a doctor and nurse while on home IV antibiotic therapy?
At least once a week
349
For a patient who is on home IV antibiotic therapy, what are 4 aspects of care that should be monitored by the physician?
1. Ongoing clinical and lab evaluation of the illness being treated with thoughts on when to change to oral therapy2. Evaluation of the IV site and functioning of the vascular access device for any evidence of infection or thrombosis3. Compliance with therapy and IV site care4. Monitoring for adverse drug effects, drug levels if needed
350
Which of the following is false:a. Home iv therapy for children is cost effectiveb. home IV therapy for children providers improved QOL and greater satisfaction to patients and familiesc. home iv programs should have written protocols for assessment and selection of patientsd. Home IV therapy for infections/PN is less effective and less safe than IV therapy in hospital
D!! It is equally as safe!
351
What is the meningococcus vaccination schedule for:-normal child-high risk (asplenic, primary immunodeficiency or complement deficiency, traveling to high risk area, exposed in military or lab)
Normal child:1. MCV-C (Menjugate) @ 1 yo2. MCV-C booster OR MCV-4 (A, C, Y, W135) = menactra in grade 7 High risk:1. MCV-C (Menjugate) @ 2, 4, 12 mo2. MCV-4 @ 2 yo 3. 4CMENB for immunocompromised, complement deficiency, asplenia, previous menincoccus invasive disease, lab workers = 3 dose series
