CPS Infectious/Immunization Flashcards
What is the risk of mortality from IE due to strep viridans infection of prosthetic valves vs. of native valves?
Prosthetic valves: 20%
Native valves: 5%
What are the 7 indications for prophylaxis against IE in patients undergoing dental procedures?
- Previous infective endocarditis
- Prosthetic cardiac valves
- Cardiac transplant recipients who develop cardiac valvulopathy
- Unrepaired cyanotic congenital heart disease (including palliative shunts and conduits)
- Completely repaired cyanotic CHD with prosthetic material or device during the first 6 months after procedure (ie. until endothelialization of prosthetic material occurs)
- Repaired CHD with residual defects at site of prosthetic patch or device (incomplete endothelialization)
- Rheumatic heart disease if prosthetic valves or material used in valve repair
What is the most common underlying condition that predisposes to the acquisition of IE in the western world?
-prophylaxis prior to dental procedure?
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
Which dental procedures require abx prophylaxis for IE?
- Manipulation of gums
- Involvement of periapical region of teeth
- Perforation of oral mucosa
What is the preferred antibiotic for IE prophylaxis prior to dental procedure?
- dose?
- when to administer?
- 2nd option for allergic people
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
What respiratory tract procedures requires IE abx prophylaxis for high risk patients?
Any procedure that involves incision or biopsy of the respiratory mucosa
-ex. T&A
What GI or GU tract procedures requires IE abx prophylaxis for high risk patients?
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)
What are the 3 most common clinical presentations of invasive group A strep infections?
- Soft tissue infection: Nec fasc or myositis
- Bacteremia
- Pneumonia
In which group is nec fasc more common: < 5 yo children or > 5 yo children?
<5 yo (5x higher)
In pediatric populations, what is a prominent risk factor for developing an invasive GAS infection?
Varicella infection
What is the diagnostic criteria for GAS Toxic Shock Syndrome?
Hypotension + at least two of the following:
- Renal impairment
- Coagulopathy (decreased platelets or DIC)
- Liver enzyme or function abnormality
- ARDS
- Generalized erythematous macular rash that may desquamate
**Think hypotension + involvement of at 2 organ systems (heme, renal, liver, derm, lungs)
Who is considered a close contact of a person with invasive GAS infection? (7)
- Household conatcts who have spent at least 4 hr per day on average in previous week
- Shared the same bed or had sex
- Direct mucous membrane contact (kissing, mouth to mouth resusc, touched open skin lesion)
- Injection drug users who shared needles
- Share long term care facility
- Share home daycare
- Selected hospital contacts
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?
Who should receive:
- 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
What is the definition of confirmed case of GAS?
Laboratory confirmation of GAS infection (isolation of GAS from a normally sterile site) with or without clinical evidence of invasive disease
What is the preferred chemoprophylaxis agent for close contacts of GAS invasive infection?
- alternative agents?
- alternative agents for beta-lactam allergy?
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
What is the recommendation on whether routine cultures should be drawn on close contacts of GAS invasive infection receiving abx chemoprophylaxis?
No routine cultures are required unless symptomatic
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?
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
What is Palivizumab?
- dose, route, timing of administration
- how much is a dose?
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
The majority of RSV hospitalizations occur in what group of infants?
Term infants with no pre-existing risk factors
What is the drug efficacy of palivizumab for prevention of RSV and associated hospitalizations?
55%
Which high-risk children should receive palivizumab to prevent RSV hospitalization? (3)
- Children with CLD who require ongoing medical therapy
- Children with hemodynamically significant CHD who are younger than 2 yo at the start of RSV season (November-ish)
- Infants < 32 wks GA who are younger than 6 months of age at the start of RSV season
What is the recommendation for use of palivizumab in children born between 32 wks-35+6 wks GA?
- Depending on provincial funding available, should come up with a policy on which of these infants should receive palivizmuab
- 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)
What is the recommendation for use of palivizumab in infants in remote communities who would require air transport for hospitalization?
- 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 doses - Should consider giving to term Inuit infants < 6 mo in communities with documented persistent high rates of RSV hospitalizations
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?
Not routinely recommended BUT may be considered for children
What is the incubation period of chicken pox?
10-21 days after contact
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)
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
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
When would you order a CBC and blood culture in a child diagnosed with pneumonia? (2)
- Clinically worsening
2. Hospitalized
What are features of atypical pneumonia (ie. mycoplasma pneumoniae)? (5)
-treatment?
- Subacute onset
- Prominent cough
- Minimal leukocytosis
- Nonlobar infiltrate
- School aged child
- treatment: clarithromycin or azithromycin
What is the antibiotic treatment for:
- nonsevere pneumonia
- severe pneumonia
Nonsevere: high dose amoxil or amp IV
Severe: ceftriaxone IV or cefotaxime IV plus clarithromycin PO or azithromycin PO/IV
What is the treatment for a child with proven or clinically suspected influenza plus evidence of secondary bacterial pneumonia?
- Consider adding antiviral for influenza
- Amoxi-clav PO or cefuroxime IV for non severe
- Ceftriaxone IV or cefotaxime IV + clarithromycin PO or azithromycin PO/IV
**some experts recommend adding cloxacillin
What is the treatment for a child with pneumonia and moderate-to-large effusion?
- Consider pleurocentesis
- Ceftriaxone or cefotaxime IV
**some experts recommend adding clindamycin
What is the treatment for a child with pneumonia that could be due to MRSA?
- Add vancomycin or linezolid to the antibiotic you’ve aleady started (ie. Amoxil, ampicillin, cephalosporins)
What is the rationale for using 3rd generation cephalosporin in treating severe pneumonias (ie. what makes it better than amoxil or amp?)
- May offer better coverage for pen-resistant pneumococcus (controversial)
- Better coverage for H flu and moraxella catarrhalis (rare in healthy, immunized children)
What is the management of a patient with pneumonia who failed to improve after 48 hrs of therapy with a beta lactam alone?
- CXR to r/o empyema
2. Consider adding clarithromycin or azithromycin for atypical pneumonia
What features are seen in exudative pleural effusion? (5)
- Low glucose (1000)
- High WBCs
- Bacterial growth
- Low pH (<7.2)
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 growing
Severe 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
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
What are two recommended strategies for decreasing seasonal influenza risk in infants < 6 months?
- Immunize caregivers and family of the infant
- 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!
Name 5 ways pediatricians can increase influenza protection for young babies?
- Educate pregnant women or women planning to become pregnant to get influenza vaccine
- Encourage them to get the vaccine as soon as it is avaialble before the influenza season starts
- Update medical colleagues who deal with pregnant women to advocate for influenza immunization
- Encourage hand hygiene
- Encourage and facilitate whenever possible influenza immunization of all household contacts of infants younger than 6 mo of age
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
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)
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
What 4 systems are affected in lyme disease?
- Skin (most common): erythema migrans
- Joints (50%): arthalgia, arthritis (usually involving knees)
- CNS (10%): headaches, facial nerve palsy (most commonly), meningitis
- Heart (5%): AV block
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
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
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
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 days
CNS lyme disease:
- IV ceftriaxone x 14-28 d
- facial nerve palsy MAY be treated with PO abx but talk to ID first
CVS lyme disease (heart block): IV ceftriaxone with switch to PO when improved x 14-21 d
Arthritis: PO amoxil or doxycycline x 1-2 mo until improvement in swelling
-if no improvement after 2 mo, IV ceftriaxone
What is the management of persistent Lyme disease arthritis that has not responded to PO or IV abx?
- NSAIDs
- Consult with Lyme disease expert
- Hydroxychloroquine (antiinflammatory and antispirochetal effect)
- If persists > 1 yr, may need arthroscopic synovectomy
In which populations does the TST have poor sensitivity (ie. false negatives)? (4)
- Infants and very young children
- Immunocompromised pts
- Patients with active and/or disseminated TB infection
- Recent MMR vaccination
In which populations does the TST have poor specificity (ie. false positives)? (3)
- Previously vaccinated individuals with BCG
2. Individuals with non-TB mycobacterium
What are the 5 indications for targeted TB screening with a TST in children?
- Children with suspected active TB disease
- Children of known cases of active TB
- Children with known RFs for progression of infection to disease (ie. immunocompromised) or starting immunosuppressive therapy
- Children who arrived in Canada from countries with high TB incidence within the last 2 years
- Children travelling or residing for 3 or more months in area with high incidence of TB
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
What are the recommendations for the use of IGRA in diagnosing LTBI?
-what about immunocompromised children?
- 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 true
- 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
Does a negative IGRA or TST rule out active TB?
NO!
-remember that both can be falsely negative in active TB disease
What are the risk factors for the development of latent TB –> active TB?
- high risk (6)
- increased risk (6)
- low risk (1)
High risk:
- Immunocompromised: HIV/AIDS, post-transplant patients
- Chronic renal failure needing hemodialysis
- Recent acquisition of TB (2 years or less) = highest risk of activated TB is within 2 years of contracting it
- Head and neck cancer
- Silicosis
- Abnormal CXR with fibronodular disease
Increased risk:
- Glucocorticoid use
- Diabetes mellitus
- malnourished
- Young age (0-4 yo)
- Smoker
- Abnormal CXR (granuloma)
Low risk:
1. Infected person (LTBI) but no risk factors and normal CXR
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
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
According to systematic reviews, what clinical features when present together in an infant < 24 months are highly suggestive of a UTI? (3)
- Fever > 39 rectal2. Fever > 48 hours3. No other source for fever
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
Which organisms will give you a positive nitrite on urinalysis?
Gram negative bacteria
What is the sensitivity and specificity for pyuria in diagnosing UTI?
Sensitivity: 73%Specificity: 81%
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%
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%
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
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
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
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)
When should aminoglycoside levels and renal function be monitored during UTI therapy?
Monitor when the aminoglycoside is continued > 48 hrs
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
What are features of a complicated UTI? (6)
- 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
What is the management of a complicated UTI?
- Renal and bladder ultrasound to look for obstruction or abscess2. IV abx until clinical improvement
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
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
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
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
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 valces
2. Vesicourethral reflux
What is the appropriate way to obtain a urine sample from a toilet trained child?
Midstream urine sample
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
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
How do you remove a tick?
- 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
What bacteria causes lyme disease and which species in Canada carries it?
Borrelia burgdorferi-in Canada, only the black legged tick carries it
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
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
What are the adverse effects of DEET? (3)
- Contact dermatitis - most common2. Eye irritation3. Toxic encephalopathy - has been reported with prolonged/excessive use or ingestion
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
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
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.
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)
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.
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
What is the recommendation of use for PMD-containing repellents?
Use only in individuals > 3 yo
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.
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!
What is the possible side effect of palivizumab?
Anaphylaxis
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
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
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?
- 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 mouth
- 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)
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
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
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
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
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
What are the overall recommendations for daycare providers in regards to biting children? (5)
- Each child care facility should have a written policy for managing child and employee exposure to blood and body fluids
- Staff should be adequately trained in caring for wounds
- First aid equipment should be available (gloves, skin disinfectant, dressings)
- 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 low
- 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
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
What are measures that may help decrease biting incidents in daycare?
- Avoidance of stressful situations, frustrations and conflicts
- Provision of age appropriate small group activities
- Observation of how, when and why a child bites to help guide prevention and management
- Paying attention first to the victim, not the biter
- Firm statements to the biter that this is not acceptable behaviour and will not be tolerated
- Directing the biter to appropriate activities
- Positive reinforcement of appropriate behaviour
- Collaboration with the family
What are the recommendations for HBV prevention in a day care setting?
- All daycare staff should be immunized against HBV
2. Encourage all parents to get their children immunized against HBV
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 child
B. 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
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:
- Moderate or severe tissue damage (unlikely with young children)
- Deep puncture wounds
- 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
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?
- Hepatitis B immunoglobulin (0.06 ml/kg IM)
- HBV vaccine
- Arrange f/u to complete HBV vaccines and for HBV serology at 6 months after known HBV exposure
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?
- Hepatitis B immunoglobulin (0.06 ml/kg IM)
- HBV vaccine
- Arrange f/u to complete HBV vaccines and for HBV serology at 6 months after known HBV exposure
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?
- No HBV testing: there is a low risk of infection and thus, HBV testing is not justified.
- Nonimmune child should receive HBV vaccine (biter or bitten child)
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.
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?
- Consult ID for advice
- 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 bite - Arrange f/u to check HIV serologies at 6 wks, 3 mo, 6 mo.
Is screening of children for HIV/Hep B or Hep C after a biting incident in child care warranted if status is unknown?
No!
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
What is the prevalence of HCV infection in Canada?
1-3% but may be higher since majority of infected people are asymptomatic
HCV infection is most common in which 2 population groups?
- Hemophiliacs who received untreated factor 8 concentrates
2. IVDU
What are the major risk factors for HCV seropositivity in pregnant women? (3)
- Previous or current IV drug use
- Being the sexual partner of an IVDU
- Blood transfusion before 1990
What is the method of acquisition of HCV by children prior to adolescence?
Perinatal exposure (almost exclusively)
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)
What are the chances of spontaneous clearance of chronic HCV infection after 6 months in adults vs. children?
Adults: very unusual for this to happen
Children: 25-30% (usually occur by 7 yo)
**Overall, spontaneous clearance is more likely in children than adults
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 histology
b. Cirrhosis during childhood occurs in only a small percentage of children
c. 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
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)
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.
What are the circumstances when HCV clearance can occur in children? (3)
- In 25% of acute HCV cases
- In an undetermined small percentage of chronic HCV
- Successful antiviral therapy
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.
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!
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.
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:
- Seronegative (immunosilent) HCV - seen mainly in HIV coinfected adults or immunocompromised patients (incidence in children is unknown)
- Very very early acute HCV (typically 20-60 days prior to testing so no time for abs to develop yet)
