ID CPS 2 Flashcards
What are the 3 stages of lyme disease?
- Early localized disease: erythema migrans (painless and non-pruritic), may have fever, malaise, headache, myalgia and arthralgia2. Early disseminated disease: recurrence of erythema migrans distributed throughout body (cutaneous dissemination of spirochetemia), lyme carditis, facial nerve palsy, aseptic meningitis3. Late disease: large joint arthritis (usually knees)
Why is 2 step testing required for lyme disease diagnosis?-causes for false positives?
ELISA first, then western blot-western blot is necessary to confirm diagnosis since ELISA can be falsely positive from other spirochetes, viral infections or autoimmune diseases
What is the Jarisch-Herxheimer reaction?
Fever, headache, myalgia and aggravated clinical picture lasting
A child who has completed the full course of Lyme disease antibiotic treatment returns within 3 months with chronic complaints of fatigue, joint and muscle aches. What is your diagnosis?
Post-treatment lyme disease syndrome-exact cause unknown-10-20% of cases-lingering symptoms may be result of residual damage to tissues and immune system-this is NOT evidence of persistent infection-no treatment available (more abx will not help)
What is the recommendation for post-exopsure prophylaxis for lyme disease?-when is it indicated?
There is no consensus on whether we should do it-some experts recommend for children > 8 yo after a tick bite in a known endemic area: doxycycline PO x 1 dose within 72 hrs of removing a tick-insufficient data to suggest amoxil prophylaxis for young children
A mother comes to you with mastitis and a breast abscess. She asks if she should continue breastfeeding. What do you recommend?
Continue breastfeeding UNLESS there is obvious pus! If there is, then pump milk and discard from the infected breast and continue to breastfeed from the other breast
A mother comes to you with a new diagnosis of TB. She asks if she should continue breastfeeding. What do you recommend?
Main route of transmission is airborne, NOT via breastmilk BUT tell mom to delay breastfeeding until she has received 2 wks of appropriate anti-TB therapy. -should also provide TB prophylaxis for infant-infant can be fed EBM during the 2 weeks of no breastfeeding
What are the only maternal infections that are a contraindication to breastfeeding? (5)
- HIV2. Human T cell lymphotrophic virus (HTLV)3. TB (until mom has completed 2 wk course of anti TB meds)4. Untreated Brucellosis (infection may be passed through breast milk) 5. HSV lesions directly on the breast (until lesions are crusted over) - can still use EBM
Can mothers with Hep A, B or C breastfeed?
Yes! -For Hep A, give baby Hep A immunoglobulin for prophylaxis.-For Hep B, give baby infant HBV immunoglobulin at birth and immunization with HBV vaccine
What is a contraindication to primiquine treatment for malaria?
G6PD deficiency
Which is the only antibiotic where you should discontinue breastfeeding x 12-24 hrs to allow excretion of dose after taking each dose?
High-dose metronidazole
What are nits?
Eggshells where baby lice (nymphs) are born from
What is an infestation with lice called?-how are head lice transmitted?-how do you make a definitive diagnosis of head lice?
Pediculosis-direct hair-to-hair contact-controversial whether fomites can transmit lice-definitive diagnosis requires detection of a living louse (presence of nits may indicate that a past infestation occured but may not be currently active if you cannot find a louse)
What are the different treatment options for head lice infestations?
***Need 2 treatments 1 wk apart-minimize body exposure, do not let the child sit in the bath water as the hair is being rinsed!1. Pyrethrins shampoo-caution in people who have ragweed allergy as may cause allergic reaction-safe2. Permethrin rinse-safe3. Lindane shampoo (2nd line)-neurotoxicity to both lice and humans-concerns with bone marrow suppression with skin absorption-do NOT use in young children, infants, pregnant/nursing mothers or people with history of seizures4. Noninsecticide = Resultz (myristate/cyclomethicone)-dissolves waxy exoskeleton of louse leading to dehydration and death-do not use for children
You have treated a child for head lice but they come back within a week with continued infestation. What is your differential diagnosis for treatment failure? (3)
- Wrong diagnosis? Make sure you look again for a living LOUSE before you say this is treatment failure (not just presence of nits)2. Poor compliance with instructions for proper application of topical insecticide or lack of secondary application or reapplication too soon after 1st3. New infestation acquired after treatment
You have treated a child for head lice but they come back within a week with continued scalp itching. What do you tell them?
Itching post-topical insecticide is common and does NOT mean that a reinfestation has occurred! Topical insecticide can cause rash/itching. Topical steroids/antihistamines may help.
Is wet combing useful either alone or in combination with a topical insecticide for curing head lice infestations?
No! Shown in multiple trials to not be useful
You have diagnosed a child with head lice infestation. Mom asks if he should be kept home from school until he is lice-free. What do you say?-mom also asks you if she should disinfect all his personal items. What do you say?
No! He can still go to school as long as there is no head-to-head contact! -no clear data on whether disinfection of fomites leads to decreased chance of reinfestation. -Head lice cannot survive far away from scalp and nits are unlikely to hatch at room temperature.-so overall, just clean things with intimate contact with the head like hats, brushes/combs, pillowcases –> dry in hot dryer x 15 mins, place in occlusive plastic bag x 2 wks, or wash in hot water
What is the risk of vertical transmission with:-untreated primary or secondary syphilis-early latent syphilis-late latent syphilis
-Untreated primary or secondary syphilis: 70-100%-early latent syphilis: 40%-late latent syphilis: 10%
A baby is born but mom has never been tested for syphilis. Baby is completely well and mom wants to go home. What is your management?
If syphilis serology was not performed during pregnancy, do not discharge the newborn home until maternal serology has been drawn and follow-up of results has been arranged
What is the infectious etiology of syphilis?
Treponema pallidum
What are causes of false-positive tests for syphilis? (2)
- Autoimmune conditions2. Lyme disease
What is the screening approach used in Canada for syphilis?-which of the tests will remain positive for life despite treatment?-which of the tests is used to monitor effectiveness of treatment?
Use nontreponemal tests (RPR ie rapid plasma reagin) or VDRL ie. venereal disease research lab test) as initial screen, then confirm a reactive result with a treponemal test (fluorescent treponemal antibody absorption test = FTA-ABs)-treponemal tests remain positive for life (ie. FTA-ABs)-RPR titres is used to stage infection and to monitor the response to treatment (may revert to nonreactive after treatment)
A pregnant woman comes to you with a reactive treponemal test and a nonreactive RPR during pregnancy with no history of treatment and no evidence of early primary syphilis. What do you do?
This is a sign of late latent syphilis and thus there is risk of vertical transmission thus you TREAT for late latent syphilis: Benzathine Pen G x 3 doses on weekly basis
A pregnant woman comes to you with a reactive RGR and negative treponemal tests (FTA-ABS & TP-PA). What is your diagnosis?
False positive! It is not possible for your RPR to be positive while treponemal tests are negative in true syphilis!
What is the most common way that congenital syphilis is diagnosed?
Diagnosis relies on positive lab and/or radiographic findings since MOST infants with early congenital syphilis (syphilis diagnosed in 1st 2 years of life) are asymptomatic at birth
Aside from laboratory testing, how else can you diagnose congenital syphilis?
You can examine any skin lesions, nasal discharge, placental lesions or umbilical cord for treponemes with darkfield microscopy or FTA-ABS
What is necrotizing funisitis?
Umbilical cord that looks like a barbershop pole: pathognomonic finding for congenital syphilis
What are the clinical features of congenital syphilis? (9)
- Spontaneous abortion/stillbirth/hydrops fetalis: 40% of cases if acquired during pregnancy2. Necrotizing funisitis3. Rhinitis/snufles4. Diffuse maculopapular rash including palms/soles5. HSM6. Lymphadenopathy7. Neurosyphilis8. Osteochondritis/perichondritis seen radiographically9. Anemia/thrombocytopenia
What are late clinical features of congenital syphilis? (4)
- Interstitial keratitis2. Hutchinson teeth3. Mulberry molars4. 8th CN deafness
A pregnant woman with a well-documented history of adequate treatment of syphilis BEFORE pregnancy who had no rise in her RPR titre during the pregnancy and no other risk factors for infection delivers her baby. What is your management of the baby?
No need for further testing or treatment.
A pregnant woman was treated for primary/secondary/early latent syphilis during pregnancy > 4 wks prior to delivery with an adequate fall in RPR titres. There is no evidence of relapse or reinfection. She delivers her baby. What is your management of baby?
- Baseline and MONTHLY assessment of baby for s/s for congenital syphilis x 3 mo2. Syphilis serological tests: RPR, treponemal tests at 0, 3, 6, 18 mo-lower risk of acquisition so no empiric treatment
What is your management plan if a baby is born to a mother with untreated primary or secondary syphilis and baby is found to have rising RPR titre, clinical findings of congenital syphilis, and positive treponemal test?
- RPR & treponemal tests at 0, 3, 6, 18 mo2. Long bone radiographs (to assess for osteochondritis/perichondritis)3. Bloodwork: CBC + diff (to look for anemia/thrombocytopenia)4. CSF sampling for cell count/biochem/VDRL (poor sensitivity but excellent specificity) to r/o neurosyphilis5. Ophtho & Audio assesment6. Treatment for congenital syphilis: Pen G IV x 10-14 d***You repeat serology often because Pen G does not cure every case of congenital syphilis
Why are children more prone to getting AOM than adults? (4)
- Eustachian tubes are shorter and more horizontal2. Eustachian tubes are more prone to obstruction by enlarged adenoids3. Viral infections/allergies more common in young children leading to eustachian tube inflammation4. Children have decreased levels of IgA and thus get more bacterial adherence in the nasopharynx
What is the pathophysiology behind the development of AOM?
Obstruction of eustachian tube (usually caused by viral infection causing eustachian tube inflammation) –> mucociliary clearance impairment –> mucus trapping in middle ear space –> resoprtion of gases within the middle ear space creates a pressure differential (vaccuum) and sucks bacteria from the nasopharynx into the middle ear space –> bacteria grow and cause infection
What are the risk factors for development of AOM? (12)
- Young age2. Daycare attendance3. Craniofacial abnormalities (cleft palate)4. Down syndrome5. Household crowding6. Exposure to cigarette smoke7. Premature birth8. Bottlefeeding9. Immunodeficiency10. Family history of AOM11. First nations/Inuit12. Pacifier use (related to frequency of use)
What are clinical features of AOM? (3 main categories)
- Signs of middle ear effusion:-immobile TM or acute otorrhea (ruptured TM)-dull TM-loss of bony landmarks behind TM-visible air fluid level behind TM2. Signs of middle ear inflammation:-bulging TM with marked discoloration 3. Acute onset of symptoms:-rapid onset of ear pain or unexplained irritability in a preverbal child
What is the most common cause of AOM?
Non typable H influenza -used to be strep pneumo but now that we have the conjugated pneumococcal vaccine, strep pneumo is less common
When is the watchful waiting approach appropriate in antibiotic treatment of AOM?
If child is > 6 mo, healthy (ie. no immunodeficiency, chronic health issues, history of complicated otitis media) with MILD signs and symptoms and parents are capable of recognizing worsening and can access medical care quickly-ie. mild otalgia, fever
What are 3 complications of untreated AOM?
- Mastoiditis2. Meningitis3. Intracranial abscess
AOM caused by which organism is the least likely to spontaneously resolve?
Strep pneumo (20% spontaneous resolution compared with 50% seen with H flu)
What are the risk factors for AOM with antimicrobial resistant S. pneumo? (4)
- Daycare attendance (more likely to be colonized due to increased contact with other children2.
Which oral drug is most likely to be effective against penicillin-resistant S. pneumo AOM?
Amoxicillin!!! Even though it is a penicillin, if given in a high dose, it has excellent middle ear penetration and thus reaches a high enough concentration to overcome most resistant strep pneumo species
What is the 2nd line therapy for AOM if a child has a type 1 hypersensitivity (urticaria or anaphylaxis) reaction to amoxicillin? -what if the previous reaction to amoxicillin was not type 1?
Macrolide: clarithromycin or azithromycin-if not type 1 reaction, then can use 2nd generation cephalosporin (cefprozil, cefuroxime axetil)
A child with AOM has a type 1 hypersensitivity reaction to Amoxicillin and has failed macrolide therapy. What is your management?
- Consider clindamycin or quinolone in consultation with ID specialist.2. Consider ENT referral for tympanocentesis to determine organism and to guide therapy
A patient who you’ve treated for AOM comes back to your office after 2 days of being on amoxicillin with no improvement in symptoms. What is your management?
Symptoms should’ve improved within 1-2 days of starting abx and resolve within 2-3 d of starting abx.-change the abx to target highly pen-resistant strep pneumo and beta-lactamase producing organisms-change the abx to Amoxi-clav-if this does not work, then Ceftriaxone IM/IV OD x 3 days
A 5 yo patient who was recently treated at a walk in clinic for AOM with a complete course of abx comes to you for a routine check up. On exam, you see a persisting middle ear effusion. He is otherwise completely asymptomatic now. What is your management?
DO NOTHING!-middle ear effusions can last for months after AOM despite clinical and bacteriological resolution
What is the dose and duration of treatment of amoxi-clav for AOM?
Amoxil 90 mg/kg/day + Clavulanate 6.4 mg/kg/day div BID x 10 d
What is the first line treatment for AOM? -dose?
Amoxil 90 mg/kg/day div BID
What is the appropriate duration of abx therapy for AOM?
Children > 2 yo: 5 days-children
Which children warrant a 10 d course of abx for AOM? (4)
1.
You have just diagnosed a patient with AOM. His mother asks you what she could do to prevent future AOM. What do you say? (4)-2 best vaccines to prevent AOM?
- Hand hygiene!2. Exclusive breastfeeding until at least 3 months of age-due to absence of bottle feeding which is a RF and also to maternal immunoglobulin transfer3. No smoking!4. Limit use of pacifier -two best vaccines: influenza vaccine and pneumococcal conjugate
Why does bottle feeding lead to increased risk of AOM?
Especially if bottle is propped, baby has to suck hard and excessively to get milk –> this generates negative pressure inside within the eustachian tube thus pulling bacteria from the nasopharynx in
What is the most common diarrheal illness associated with hospitalization?-which age group has the highest risk of severe disease?
Rotavirus-highest risk of severe disease = children
How long do rotavirus infections last for?-most commonly seen symptoms? (3)
3-8 days1. Vomiting2. Diarrhea3. Fever
What are risk factors for severe rotavirus disease? (3)
- Premature babies (lack transplacental maternal abs)2. Immunocompromised3. Children
What are the two rotavirus vaccines available in Canada?-similar characteristics-distinguishing features
Both given orally at minimum of 6 wks with maximum age for dose 1 of 14 wks + 6 d of age, doses given 1 month apart1. RotaTeq-3 doses required-covers G1-G4P & P1-live, pentavalent vaccine2. Rotarix-2 doses required-covers G1P-live-attenuated monovalent (G1 is the most common circulating strain worldwide and other circulating strains are rare)
What are possible adverse effects of RotaTeq vaccine? (5)
- Vomiting2. Diarrhea3. Nasopharyngitis4. Otitis media5. Bronchospasm***These are small but statistically significant
What are contraindications to rotavirus vaccines? (3)
- Hypersensitivity to the vaccine or ingredients2. Immunocompromised3. History of intussusception (based only on previous association with RotaShield with pathogenesis still unclear)***These is no association between the new vaccines and intussusception
What is the recommended age group for rotavirus vaccine?-who should receive rotavirus vaccine?
Vaccination should be started between 6-14 wks+6 days of age and be FINISHED by 8 months of age (safety of vaccine outside of these recommendations is unknown)-recommended for ALL infants because it significantly decreases the incidence and morbidity associated with rotavirus infection-may not prevent all cases of rotavirus diarrhea but do prevent severe disease and decreases risk of dehydration and hospitalization
Define the following:1. Sterilants2. Disinfectants3. Sanitizers4. Fungicides
- Sterilants: will kill all forms of microbial life2. Disinfectants: kill infectious pathogenic bacteria3. Sanitizers: reduce the amount of microbial contamination4. Fungicides: destroy fungi on inanimate surfaces that are pathogenic
What are the antimicrobical mechanisms of action of the following:1. Alcohol2. Chlorhexidine3. Triclosan4. Quaternary ammonium compounds
- Alcohol: denature proteins2. Chlorhexidine: Disrupts cytoplasmic membrane3. Triclosan: disrupts cytoplasmic membranes, inhibits synthesis of RNA/fatty acids/proteins4. Quaternary ammonium compounds: disrupt cytoplasmic membrane
What is the recommended cleaning agent for spillage of body fluids?
Diluted bleach
What is the most common mechanism of resistance to antibiotics that bacteria exhibit?-which cleaning agent has been shown to upregulate this mechanism?
Multidrug efflux pumps!-concerning since this can result in cross-resistance to other antibiotics that the bacteria were not initially exposed to since multidrug efflux pumps are nonspecific in what they pump out of the cell-pineoil has been shown to upregulate the efflux pumps, leading to resistance to several antibiotics
Is there definitive evidence that the use of biocides in cleaning products has contributed to the development of antibiotic resistance?
No….but there are relationships between antibiotic resistance and biocides that are mediated by a target gene mutation or increased expression of multidrug efflux pumps! Needs more research.
What is the procedure for cleaning up a body fluid spill at home?
- Wipe up the spill with paper towels and place in a plastic garbage bag. 2. Make a solution of 9 parts water and 1 part bleach and pour onto contaminated surface3. Wait 20 minutes.4. Wipe up the bleach solution5. Disinfect all nondisposable cleaning materials used (ie. mops/brushes) by saturating them with bleach solution and allow to air dry6. Throw out everything else in the plastic garbage bag.7. Wash your hands!
Which of the following is false:a. the CPS recommends the use of antimicrobial-impregnated household productsb. The CPS promotes hand hygiene using plain soap and water in the vast majority of domestic settingsc. Antimicrobial chemical agents may be used selectively in the home ni specific high-risk scenarios (ie. immunocompromised, neonate, old person)d. Where appropriate, alcohol, bleach or peroxidase based agents are preferred sicne they dissipate readily and are less likely to exert prolonged antimicrobial pressure
A! They do NOT recommend this! Use of antiseptics and antimicrobials is unnecessary!
What is the mechanism of action of biologic response modifiers?-examples of a biologic response modifier?-schedule of administration?
Block the action of cytokines involved in inflammation in order to decrease inflammation-ie. TNF-alpha inhibitors (infliximab ie remicade, adalimumab ie. humira), interleukin inhibitors (Abatacept)-administered IV or subcutaneously weekly, q2wk, monthly or bimonthly depending on the disease being treated
What type of immunity is supprsesed by biologic response modifiers?
Cellular immunity - decrease ability of T cells to destroy cells with intracellular pathogens, decreased ability for granuloma formation
One of your patients is on a biologic response modifier for treatment of their JIA. What 3 types of infections are they at increased risk of acquiring?
- Mycobacteria: TB and non-TB2. Fungal3. Intracellular bacteria (listeria)-no evidence regarding increased risk of common bacterial infections-some evidence of viral reactivation with HSV/EBV, etc.
What is the work-up/counselling for a patient before initiation of biologic response modifier therapy? (7)
(Rule out latent TB):1. TST2. CXR(Investigate for latent viruses):3. Document vaccination status and verify all are up to date, including yearly influenza vaccine. Administer live virus vaccines a minimum of 4 weeks before initiation of BRM unless contraindicated4. Serology for Hep B, VZV, EBV(Rule out intracellular pathogens):5. Serology for histoplasma, toxoplasma, other intracellular pathogens(Counsel):6. Counsel household members for vaccination7. Counsel patient re: food safety, dental hygiene, avoid exposure to garden soil/pets/other animals, travel to endemic areas for pathogenic fungi or TB
A patient of yours with IBD needs to be started on remicade. You perform a TST as routine workup prior to starting remicade and the induration is found to be 8 mm. CXR is normal. What is your management?
- Diagnose patient with latent TB infection2. Treat for LTBI with isoniazid x 9 months.3. After patient has been on isoniazid x 1 month, can start treatment with remicade.
You are starting a patient on a biologic response modifier for their IBD. They ask you how to decrease risk of infection while immunosuppressed. What counselling do you provide re:-food safety?-contact safety?-which organism are you avoiding with each of your recommendations?
- Food safety (decrease risk of infection with listeria, toxoplasma, etc.)-avoid undercooked meat/eggs/deli meats-avoid raw eggs or unpasteurized milk products (soft cheese)2. Contact safety:-avoid soil or kitty litter (for toxoplasmosis)-avoid kittens (bartonella)-avoid pet reptiles (for salmonella)-avoid pet bites or scratches (pasteurella)-avoid construction sites, farmyard barns, cave exploration (high concentration of fungal spores)
A patient received an MMR vaccination today but you also want to test them with a TST for TB. When is the earliest you can administer the TST to avoid a false negative?
4-6 wks after MMR immunization
What organism is the most common cause of skin abscesses in previously well children?-which organism is becoming a more common cause of skin abscesses?
Staph aureus (MSSA)-MRSA is becoming a more common cause of skin abscesses!-resistant to all beta-lactam antibiodies (including penicillins and cephalosporins)
In the management of skin abscesses, what is the only way to distinguish between MSSA and MRSA as the cause?
Swab the discharge or pus from an infected skin abscess and send for culture!
What are risk factors associated with the SPREAD of community-associated MRSA in the child or family? (5)
- Close skin-to-skin contact2. Poor hygiene3. Crowded living conditions4. Openings in the skin (cuts/abrasions)5. Contaminated items and surfaces
In which populations are there increased rates of community-acquired MRSA? (7)
- Prisoners2. Men who have sex with men3. Daycare attendees4. Military recruits5. Aboriginal populations6. Athletes7. IV drug users
What is the management of a skin abscess in a previously well child > 3 mo who is otherwise asymptomatic?
Most children can be managed initially with drainage alone (regardless of whether the cause is MSSA or MRSA). -should be reassessed if they develop systemic symptoms, have worsening local symptoms or have demonstrated no improvement after 48 hrs
A 20 do baby comes to you with a skin abscess. The abscess is 2 cm and the baby is otherwise well. What is your management plan?-what if the abscess was
For neonates 1 cm:1. I&D of the abscess2. Admit for IV antibiotics (vancomycin +/- other agent) with step down to PO therapy when improved for total 7 d course **Outpt management with clindamycin can be considered IF the abscess is
A 2 month old infant comes to you with a skin abscess. She is otherwise well. What is your management plan?
- I&D2. TMP/SMX PO x 7 d pending cultures3. Can d/c home with close f/u if there is no fever/systemic signs of illness***For children 1-3 mo of age with no fever/systemic signs of illness with skin abscess, do septra PO and f/u closely
A 6 mo infant comes to you with a skin abscess. There is no history of fever and she is otherwise well. What is your management plan?
For children > 3 mo with a skin abscess who are afebrile and systemically well:1. I&D2. Observe after drainage and f/u closely***Consider antibiotics ONLY if the child does not improve or if the culture grows an organism other than MSSA
A 6 mo infant comes to you with a skin abscess. There is significant surrounding cellulitis but the child is afebrile and systemically well. What is your management plan?
For children > 3 mo with skin abscess and significant surrounding cellulitis with no fever and no systemic signs of ilness:1. I&D2. TMP/SMX + Cephalexin PO x 7 d pending cultures3. F/U closely for improvement
A 6 mo infant comes to you with a skin abscess. She has a fever and is systemically unwell. What is your management?
For children with a skin abscess and fever or systemic signs of illness:1. I&D2. Admit for IV abx
In the limited situations in which one chooses to use antibiotics, what is the best antibiotic choice for treatment of skin abscess postdrainage? What is the limitation of this drug?-2nd option available?
TMP/SMX! Covers almost 100% of MSSA and CA-MRSA and is well tolerated-Limitation: poor coverage for GAS (but this is a rare cause of skin abscesses and abscesses due to GAS are likely to resolve postdrainage with no adjunctive antibiotics)-2nd option: doxycycline for children > 8 yo and can swallow pills
Once a child has been colonized with MRSA, is decolonization recommended?
No. Failure is common even with multiple decolonization attempts.
What are the only 4 circumstances where you would consider starting antibiotics for a skin abscess?
Remember that the VAST majority of skin abscesses resolve post-drainage WITHOUT antibiotics! May choose to start in the following circumstances only:1. Infant
Which population has the highest rate of influenza attributable hospitalizations in any pediatric age group?
Infants
Why are influenza vaccines not licensed or recommended for infants
Response to vaccine has been variable and vaccine effectiveness is unclear
What is the evidence on cocooning programs vs. immunizing pregnant women for protecting infants
-Cocooning (ie. vaccinating postpartum mom and household contacts) = shown to be costly, difficult to implement on larger scale-immunizing pregnant women during 2nd or 3rd trimester: shown in RCTs to be clinically effective, safe, and cost effective with decreased hospitalization rates for both mothers and infants during influenza season. ALSO, have been shown to have reduced frequency of preterm and SGA deliveries**overall: best strategy to prevent influenza in
What are the possible complications of influenza infection during 1st trimester of pregnancy?-prevention?
Congenital anomalies = neural tube defects, hydrocephaly, congenital heart defects, cleft lip, limb reduction defects-teratogenic effects may be from fever or host response to influenza infection-prevention: OFFER FIRST-TRIMESTER INFLUENZA IMMUNIZATION with trivalent inactivated vaccine.-flu vaccine is safe during any stage of pregnancy! (Supported by both national advisory committee on immunization and Society of obs/gyne)
In which age group is live attenuated intranasal influenza vaccine preferred over trivalent inactivated?
Children 2-6 yo because of increased efficacy and expected higher acceptance of intranasal administration compared with injection-evidence of greater efficacy in older children is weak so you can choose either LAIV or TIV in older children or high risk groups (don’t use LAIV for active severe asthma, egg allergy, kids on ASA or immunodeficiency or in pregnancy though)
What is in trivalent influenza vaccine??-what is expected to come out as a new vaccine for influenza in 2014/2015 season?
2 subtypes of influenza A and one subtype of influenza B. Since there are two circulating strains of B usually, the vaccine may not be fully effective if the strain in the vaccine for influenza B doesn’t match the dominant one in the season-quadrivalent influenza with 2 subtypes of each are expected to come out!
You are seeing a healthy infant for recurrent thrush. They are otherwise completely well but despite the multiple courses of nystatin you’ve given, the thrush keeps coming back. What do you think may be the cause of the recurrent thrush?
Ask about use of infant soother = increaes incidence of thrush and makes treatment less effective unless soother is carefully washed after use
Should you recommend topical gentian violet for oral thrush in an infant?-why or why not?
No…it’s moderately effective BUT lots of drawbacks:1. prolonged use can cause irritation and ulceration2. stains tissue and clothing and is not well accepted by parents3. Interferes with clinical assessment
A baby presents with oropharyngeal candidiasis. What is the first line treatment?-2nd line treatment?
- Nystatin suspension 200,000 units QID x 14 days (cures 50% of newborns after one week and 80% of newborns after 2 weeks)-should be given after feeds-2nd line treatments: fluconazole or itraconazole
What is the treatment for candida diaper dermatitis?
- Change diapers frequently2. Leave diapers off for long periods of time3. Topical antifungal therapy (ie. nystatin, cotrimazole ointment***unclear whether oral antifungal should be given at the same time. Also, no well designed trials to assess efficacy of adding topical steroid to the antifungal
What is pityriasis versicolor?-causative organism?-treatment?
Scaly hypo or hyperpigmented lesion on the trunk-caused by Malassezia (invades stratum corneum)-treatment: topical ketoconazole, selenium sulfide, clotrmazole (shampoo or lotion to affected area 15-30 minutes qhs x 1-2 weeks, then 1x/month x 3 months to avoid recurrences)
What are the 3 common causative agents of tinea corporis?-transmission?-treatment?
Causative agents:1. Trichophyton 2. Microsporum-transmission: direct contact with infected humans, animals (dogs/cats)-treatment: topical clotrimazole, ketoconazole or terbinafine OD or BID x 14-21 days
What is the most common pediatric superficial dermatophyte infection?-most common 2 organisms?-treatment?
Tinea capitis (fungal infection of the scalp)-common causes:1. Trichophyton tonsurans2. Microsporum canis-treatment: need ORAL therapy since it does not respond well to topical therapy alone-fluconazole or ketoconazole
Why is fluconazole not used for routine treatment of most superficial fungal infections?
Hydrophilic and is thus present mainly in bodily fluids and NOT keratin or lipids (in skin)
What antifungal is help for treating resistant superficial dermatophyte infections (ie. tinea inguium aka onychomycosis), tinea pedia, tinea corporis or tinea cruris?
Oral terbinafine = $$$ though-one study says terbinafine is the drug of choice for superficial fungal infections in children!
Which drugs interact with most antifungals? (5)-which antifungal is an exception?
All are metabolized by cytochrome P450 (CYP 3A) and thus antifungals inhibit the elimination of the following drugs:1. Antiarrhythmics2. Cortisol3. Cyclosporin4. Estradiol5. Tacrolimus***Exception = terbinafine = does not affect CYP 3A, has very few drug interactions
What are the 8 components of the Canadian vaccine safety program?
- Prelicensure review and approval: government regulator conducts a thorough review of all the scientific product data for each vaccine before it can be sold2. Current good manufacturing practices: strict, globally recognized manufacturing procedures that include regular and random onsite checks of manufacturing plants by government inspectors3. Lot assessment before release: Manufacturers test every lot of vaccine for potency, safety and purity before release4. Independent expert review of national vaccine recommendations5. Post-marketing surveillance for adverse events: reoprting adverse events is mandatory for health care providers and vaccine manufacturers6. Rapid response to vaccine performance conerns7. Expert causality assessment of serious adverse events following immunization: rigorous scrutiny by group of experts to determine the cause8. International collaboration: data on adverse events following immunization is sent to WHO where ti is shared with all countries
What group in Canada is responsible for regulating licensing of drugs and vaccines?-what about in the US?
In Canada: Biologics and genetic therapies directorate of Health Canada-in US: FDA
True or false: vaccines undergo more rigorous testing and screening prior to approval than all drugs.
TRUE!-drugs do not undergo rigorous lot by lot assessment nor do they have multiple steps before getting to the shelves
Which group in Canada completes the independent expert review for vaccine use recommendations?
National Advisory Committee on Immunization-independent experts in ID, public health, vaccine safety, epidemiology, peds, nursing, internal medicine-these people are INDEPENDENT of vaccine manufacturers and government
What is the passive surveillance system for vaccines in Canada?-what about active surveillance?
Passive surveillance system = anyone, including families, patients and the general public can voluntarily submit a report to the Canadian Adverse Events Following Immunization Surveillance System (CAEFISS) run by the public health agency of canada-health care professionals are requires to report all serious adverse eventsActive surveillance: Immunization Monitoring Program, ACTive (IMPACT) is run by the CPS-uses specially trained nurse monitors to actively and systematically search all hospital admissions to the 12 children’s hospitals across the country for adverse events following immunization, for vaccine failures and for infectious diseases in children that are or are soon to be vaccine preventable
What type of virus is West Nile Virus?-what are the vectors?-what are the definitive hosts/reservoirs
Arbovirus-vector is culex mosquito (this is not the main species that we see most commonly but their peak is in the late summer when other species of mosquitoes start dying off)-definitive host/reservoir: birds (crows, jays, ravens, magpies) - Corvidae family**mosquito-bird-mosquito cycle
What part of the year is west nile virus activity present?
May until end of October with peak in late August to early September coinciding with peak mosquito activity-in warmer climates however, transmission occurs year round
True or false: Children are at higher risk of serious west nile virus infection than adults.
FALSE! Lower risk of serious infection in children-older adults are most seriously affected (meningoencephalitis)
Can west nile virus be transmitted from human to human? (3)
YES 1. organ transplantation 2. blood transfusion from infected donors3. Intrauterine transmission***however, now, organs and blood transfusions are screened for west nile virus so these are now safe
What is the incubation period for symptomatic west nile disease?-clinical features?-duration of illness
3-14 days after mosquito bite-clinical features: (most are asymptomatic)1. Nonspecific febrile illness: abrupt onset2. Headache3. Backache4. Myalgia5. Malaise/fatigue6. Arthralgias7. Maculopapular rash8. Ocular pain9. Pharyngitis10. Conjunctivitis11. Lymphadenopathy12. Resp symptoms (less common)13. Most severe complication: encephalitis/meningitis (occurs in 1:150-1:200 infections) with severe muscle weakness/paresis/flaccid paralysis***Think of things a virus causes-duration of illness: 3-6 days
What are risk factors for severe disease and death with West Nile Virus infection? (3)-long term sequelae of neurological infection with west nile virus?
- Advanced age2. Diabetes mellitus3. Immunosuppression-long term consequences: muscle weakness, fatigue, cognitive dysfunction, loss of memory, depression
What is the treatment for West Nile Virus infection?
Supportive - no effective antiviral agent known at present
You suspect a patient has been infected with west nile virus. You complete a lumbar puncture. What do you expect to see on CSF analysis?-what about CT scan? MRI?
- Normal glucose2. High protein3. Pleocytosis with lymphocyte predominance-CT scan: will be normal-MRI: may show meningeal or periventricular enhancement
How is West Nile infection diagnosed?-how long can WNV IgM stay positive for?-what is the sensitivity of WNV testing?
Serology = hemagluttination inhibition (HI) and ELISA are used first as screening tests but cross reaction with other flaviviruses can occur (ie. recent immunization for yellow fever or japanese B encephalitis, infection with dengue or st louis encephalitis virus) SO, you then confirm the positive results with a plaque reduction neutralization test (PRNT)-WNV IgM = in serum or CSF, has to be captured within 8 days of onset-IgM can stay positive for several months-a negative ELISA/HI is not very sensitive since West Nile Virus often has a low level of viremia and might be missed by these tests
A child presents with an acute febrile illness with clinical findings of encephalitis and acute flaccid paralysis. No bacterial etiology has been found on CSF and there is mild pleocytosis on CSF with lymphocytic predominance. They live near a bird sanctuary with a lot of standing water. What is your most likely diagnosis?
West Nile Virus!-this must be reported to public health asap and need to do specific west nile virus diagnostic tests
What are the clinical criteria for west nile fever?
Fever AND history of exposure to birds/mosquitoes in an area where WNV activity is occuring AND at least one of the following:1. Myalgia2. Arthralgia3. Headache4. Fatigue5. Photophobia6. Lymphadenopathy7. Maculopapular rash
What are prevention measures you can recommend to decrease west nile virus infection?
- Reduction of mosquito population: remove standing water receptacles (old tires/toys/flower pots/etc), keep swimming pools clean, clean clogged gutters, public health can drain standing water sources, use pesticides2. Reduce exposure to mosquitoes: avoid infested areas, limit outdoor times at high mosquito activity (dawn and dusk), put screens on windows and doors3. Use barriers to protect skin: mosquito nets, screens for baby strollers, protective light colored clothing with long cuffed sleeves, long pants tucked into socks or shoes4. Discourage mosquitoes from biting: use mosquito repellents
What are the recommendations for use of DEET in children? (10)
- Do not apply on open skin, around eyes and mouth2. Do not spray onto face - apply with hands3. Use just enough to cover exposed skin and avoid excessive amounts or excessive numbers of applications4. Do not apply to a young child’s hands cause they may put it in their eyes or mouth5. Don’t let young kids put it on themselves6. Don’t apply under clothing7. Don’t use sprays in enclosed areas or near food8. Avoid preps of DEET combined with sunscreen since sunscreen needs to be applied more often9. Reapply if washed off by sweating/swimming10. Wash off with soap and water once indoors
Can a human infected with west nile virus then spread the virus to a mosquito who has bitten the human?
NO! Humans and horses are “dead end” hosts and are not reservoirs for the virus unlike birds (birds and mosquitoes can infect each other back and forth)
What organisms can contaminate and cause infection in the following foods:-unpasteurized milk, cheese and dairy products-unpasteurized fruit or vegetable juices
NAME?
What organism can contaminate eggs?
Salmonella = thus should always make sure eggs are well cooked!!!
What organisms can contaminate raw fish and shell fish?
Vibrio, norovirus, hep A, parasites, toxins-children should NOT eat raw shellfish!!!
What organisms can contaminate fresh fruits and vegetables?
Cryptosporidium, cyclospora, norovirus, giardia, shigella, E coli O157, Hep A
At what age can children start having honey?
Once they are over 1 year of age-risk of botulism
What organisms can contiminate cream-filled pastries, potato/egg salads with creamy dressing?
- Staph aureus2. Bacillus cereus
Where do most foodborne infections occur: in the home setting or outside of the home setting?
In the home setting!
What are the ten rules for safe food preparation?
- Choose foods that are safe: ie. no unpasteurized milk or juices!!!! There is no nutritional benefit and its dangerous! Wash fruits and vegetables carefully2. Separate food to be eaten raw from food to be cooked: keep uncooked meat/etc. away from cooked food3. Wash hands before food prep and after touching raw food4. Cook meats, poultry, eggs and seafood thoroughly5. Eat foods soon after they are cooked (setting foods aside to cool at room temp increases risk of growth of residual microorganisms)6. Store cooked foods appropriately: keep either ABOVE 60 degrees celcius OR rapidly cooled and stored below 4 degrees celcius to avoid growth of residual microorganisms7. Reheat cooked foods adequately8. Keep the kitchen meticulously clean9. Protect foods from insects, rodents and other animals10. Always use safe water for food prep
What foodborne infections are children with immunosuppression at increased risk of severe disease? (4)
- Salmonella2. Toxoplasma3. Cryptosporidium4. Listeria
Which foods should children with immunosuppression avoid? (5)
- Raw or undercooked meats, meat pates, meat spreads2. Raw or undercooked eggs: hollandaise sauce, salad dressings, homemade mayo, homemade eggnog, uncooked cake or cookie batter3. Soft cheeses and cheeses to which live microbial cultures have been added4. Fresh fruits and veggies that are unwashed or still have their peel: need to peel all or cook them all!!! Avoid raspberries and strawberries since they cannot be easily washed or peeled!! 5. Raw seed sprouts
What route is amphothericin B given?-2 side effects?-activity?
Parenteral (IV)-side effects:1. nephrotoxicity2. infusion related events (fevers, chills, rigors)-activity: used as a broad spectrum antifungal agent
What route is fluconazole given?-possible side effects? (2)-most common uses? (ie. for which fungi?)-which fungi does fluconazole have NO activity against?
Given PO or IV-side effects:1. Hepatotoxicity2. Drug interactions since fluconazole is a cytochrome P450 inducer-most commonly used in treatment of candida and crytococcal infections (more active against candida albicans compared to other candida species)-fluconazole has NO activity against aspergillus or other moulds
What route is itraconazole given?-possible side effects? (2)-most commonly used for which fungal infections?
-IV and PO-side effects: 1. GI stuff due to osmotic properties of cyclodextrin carrier = abdo pain, vomiting, diarrhea, elevated liver enzymes2. Drug interactions: inhibitor of cytochrome P450-most commonly used for PROPHYLAXIS (prevention of candida and aspergillus infections) (hematopoietic stem cell transplant recipients); also used for prophylaxis in lung transplant recipients colonized by aspergillus, treatment for aspergillus infections
What are side effects of voriconazole? (4)-used for what fungal infection?
Side effects:1. Skin rash2. Vision changes (photophobia, blurred vision)3. photosensitivity4. Elevated liver enzymes or bilirubin levels***used primarily for invasive aspergillosis
What is the preferred treatment of invasive pulmonary aspergillosis?-what about preferred treatment of systemic candida infections?
Invasive pulmonary aspergillosis: VoriconazoleSystemic candida infections: Fluconazole
What are the clinical uses of posaconazole?
PO agent = broad spectrum activity against candida, aspergillus, zygomycetes-use as second line agent when first line antifungal agents have failed or are contraindicated due to toxicity
How do echinocandins work against fungi? -examples?-what fungi are treated with echinocandins?
Inhibit glucan synthesis and thus breaks down the fungal cell wall (humans do not have glucans so this is low toxicity in humans)-ex. caspofungin, micafungin-treat candida and aspergillus-especially useful in children with impaired renal function
What infection would you consider combination anti-fungal therapy for?
CNS fungal infections (ie. crytococcal meningitis) only = otherwise, there is no evidence that combination anti fungal therapy offers any advantages over monotherapy
A febrile neutropenic patient has a presumed fungal infection. What antifungal would you start empirically?
Amphotericin B
What antifungal would you start for candida infections (ie. intraabdominal abscess, peritonitis, pleural space infection, candidemia, esophageal candidiasis, etc.)?
Fluconazole!
Which serotype of pneumococcus has emerged as a common cause of pneumococcal disease in children due to PCV7 vaccination causing decline of other serotypes of pneumococcus?
Serotype 19A = often resistant to multiple antibiotics (usually to penicillin)***remember though that the absolute increase in the incidence of nonvaccine serotype invasive pneumococcal disease is MUCH smaller compared to the huge decline in incidence of vaccine serotype IPD disease
Which pneumococcal conjugate vaccine is now recommended for routine infant immunization? -how many doses are needed?
PCV13 (ie prevnar 13) = has the most predominant serotype of pneumococcus in it (emerged with prevnar 7) = serotype 19A in addition to all the other serotypes in other pneumococcal vaccines-4 dose schedule is recommended!-can consider giving to all healthy children (if they missed the routine stuff) 12-35 months of age and immunocompromised children (these kids should ALSO receive 23-valent polysaccharide pneumococcal vavvine after 2 years of age)
A pregnant woman has just been diagnosed with HIV. In broad terms, what are the steps that need to be taken to decrease the chance of vertical transmission?
- Start the pregnant woman on antepartum combination antiretroviral therapy (if > 4 wks prior to delivery, better chances of preventing vertical transmission)2. Intrapartum IV zidovudine for the mother3. 6 weeks of postnatal oral zidovudine for the infant4. Exclusive formula feeding of the infant***With these interventions, rate of VT has reduced from 25% to
For women at increased risk of HIV infection, how many times during pregnancy should they be tested for HIV?
3 times! Should be tested at the beginning of pregnancy; if negative, need to repeat testing at beginning of 3rd trimester AND at delivery
What are risk factors for HIV infection?
- IV drug use2. commercial sex worker3. HIV negative woman in a serodisconcordant couple4. Unprotected sexual intercourse with multiple partners
What is the ideal HIV viral load prior to delivery if a woman is on antiretrovirals?
Viral load should be
What is the recommendation for elective C section in HIV positive women?
Elective C section is recommended for HIV positive women NOT on combination antiretroviral therapy and/or anticipated to have inadequate viral suppression near delivery (viral load > 1000 copies/mL)
Which HIV positive pregnant women shuld receive IV zidovudine at the time of delivery?
ALL OF THEM!!!! Regardless of mode of delivery or viral load!
Which babies born to HIV positive women should receive MORE than zidovudine x 6 wks?-what regimen do these babies get?
- Babies born to HIV positive mothers who had antenatal cART but viral load was > 1000 copies/ml2. Babies born to HIV positive mothers who had no antenatal cART ***Zidovudine x 6 wks PLUS 3 doses of nevirapine during first week of life OR combination antiretroviral therapy
What is the ideal time frame for a baby born to an HIV positive mother to start antiretroviral therapy?
Within 6-12 hrs of birth! Efficacy decreases with increasing time after birth and is likely NOT useful when initiated beyond 72 hrs of life
Under what circumstances should consultation with a pediatric HIV expert occur when managing a newborn of an HIV positive mother?
- Mother did not consistently receive antiretroviral therapy during pregnancy2. Mother’s most recent viral load was either detectable (>40 copies/mL) or was not documented in the four weeks preceding delivery3. Mother did not receive intrapartum prophylaxis
What is the recommended test for diagnosis of HIV infection in children
HIV DNA or RNA PCR! (to avoid detecting the maternal antibodies in the serum)-if two separately timed PCR tests are negative, HIV infection can be reasonably excluded (one at 1 month of age, one at 2 months of age)-for children who received cART, at least one of the PCR tests should be done at 4 mo of age or later-then need to do ELISA, then Western blot for HIV antibodies between 18-24 months of age
What are the 2 most common side effects of zidovudine?
- Reversible anemia2. Neutropenia
A child born to an HIV positive mother (who was on antenatal antitretroviral therapy) is found to be HIV negative after a period of testing. Do they require follow-up?
Yes! Long-term follow up is needed since in utero and perinatal exposure to antiretrovirals (nucleoside analogues) are thought to cause carcinogenicity
What is the most common STI in Canada?
Chlamydia
Which adolescents should be screened for STIs (ie. what are the risk factors for acquiring an STI)?-which females?-which males?
Risk factors for acquiring STI:Females: ALL who are sexually active (since they can be asymptomatic) or victims of sexual assault or abuseMales:1. If hx suggests sexual contact with person with known STI2. Previous STI3. Being a patient of an STI clinic previously4. New sexual partner or > 2 sexual partners within the last year5. IV drug use or other substance use associated with sexual activity6. Unsafe sexual practices (unprotected sex, sharing sex toys, etc.)7. Anonymous sexual partnering (bathhouse/internet meeting/rave)8. Client of sex workers9. Survival sex: exchanging sex for money, drugs, shelter or food10. Street involvement or homelessness11. Time in detention facility12. Hx sexual assault or abuse***“Screened” means official lab testing
How often should STI screening occur for adolescents with risk factors?-what should be included in screening?-what tests are used for screening?-what test is the gold standard for medico-legal purposes (ie. in sexual assault case)
Screen for G&C in all sexually active females and males with risk factors AT LEAST ANNUALLY-after treatment, screening should be repeated q6months if risk of reinfection persists-NAAT (nucleic acid amplification test) is the most sensitive and specific test for chlamydia and gonorrhea-obtain via first-catch void urine, vaginal, endocervical or urethral specimens (validated only for these samples, not for rectal, pharyngeal, etc.)-for medicolegal purposes: culture of cervical or urethral specimen is test of choice but is less sensitive than NAAT
When should “test-of-cure” be completed for STI treatment?-for chlamydia-for gonorrhea
Test of cure using NAAT 3-4 weeks later after completion of therapy is recommended for: 1. ALL PREPUBERTAL individuals-OR POSTPUBERTAL WHEN-2. compliance is uncertain3.alternative treatment was used4. re-exposure is likely5. when pregnant
When should culture for gonorrhea be performed instead of/in addition to NAAT?
- Sexual abuse of children is suspected2. Sexual assault cases3. Treatment failure4. Evaluating PID5. Symptomatic MSM6. Infection was believed to have been acquired overseas or in area of known antimicrobial resistance***This is because of the rising rates of gonococcal resistance to cephalosporins and azithromycin
In which 2 groups has NAAT testing for chlamydia and gonorrhea not been validated?
- Children 12 years of younger2. Medicolegal specimens
Which patients with NAAT proven gonorrhea should receive cotreatment for chlamydia?
ALL PATIENTS regardless if chlamydia is detected or not!!!
Can serology be used for diagnosis of chlamydia?
NO!
What is the testing recommended for syphillis?-when should testing be repeated?
Treponemal Specific EIA is most sensitive screening test (more than nontreponemal tests ie. the rapid plasma reagin)-if treponemal specific EIA is positive, then a second treponemal test is required***Repeating serology testing:-for primary, secondary, early latent infection = 1, 3, 6, 12 months after treatment-for late latent = 12 and 24 months after treatment
Which patients should be screened for HIV?
- Pregnant women2. All patients seeking evaluation and treatment for STIs
What tests should be performed for women with symptoms of cervicitis?
- Vaginal or cervical swab for gram stain, gonorrhea and chlamydia culture (NAAT or culture)2. Swab of cervical lesions for HSV3. Vaginal swab for wet mount
Why are macrolides most effective for mycoplasma infections?
Mycoplasma is an intracellular pathogen - macrolides have diffusion to intracellular compartment and reach higher levels than in plasma concentration
Why should azithromycin be avoided in patients with significant risk of bacteremia?
Azithromycin is largely transported intracellularly rather than circulating blood thus has less impact on bacteremia
Why should we avoid use of macrolides for community-acquired pneumonia?
Increased pneumococcal resistance due to:1. Overprescribing of azithromycin for nasopharyngeal infections2. Long half life resulting in subinhibitory concentrations over several days promiting emergence of resistant strains3. Very low plasma concentrations increasing risk of therapy failure***Many studies have shown link between macrolides and nasopharyngeal carriage of resistant pneumococci
In what circumstances should azithromycin be used to treat upper/lower respiratory tract infections?
- 2nd line treatment in acute GAS pharyngitis if life-threatening beta-lactam allergy 2. Atypical bacterial pneumonia (mycoplasma)
What are primary and secondary prevention methods against STI?
- Vaccine against Hep B and HPV2. Condom useSecondary prevention:1. Partner notification2. Treatment and screening for STIs in asymptomatic young adults
