Infectious Diseases Flashcards
List the Congenital Infections
CHEAP
TORCHES
Chicken pox Hepatitis B, C, E Enterovirus AIDS Parvovirus B 19
Toxoplasmosis Other (TB, WNV) Rubella CMV HSV Every other STD Syphilis
Key features of congenital CMV
-85 - 90% are congenital CMV are asymptomatic
- IUGR
- petechiae, purpura
- thrombocytopenia
- hyperbili, HSM
- Microcephaly, periventricular calcifications
- choriorentitis, strabismus
- SNHL
Who to treat for CMV
- all symptomatic neonates with CNS involvement, SNHL, chorioretinitis
- case by case for mildly symptomatic neonates
- Valganciclovir oral x 6 months
- may use IV ganciclovir in hospitalized severely affected neonates
- monitor CBC (neutrophils) and creatinine
- long-term f/u of hearing and neurocognitive development
Key features of congenital syphilis
- IUGR
- Snuffles, maculopapular rash followed by desqumation, blistering and crusting
- HSM, LN
- coomb’s neg hemolytic anemia
- pseudoparalysis, osteochondritis, diaphyseal periostitis
- aseptic meningitis, hydrocephalus
- salt and pepper chorioretinitis, glaucoma, uveitis
-key feature differing from CMV is the bone changes here and blistering rash
When to evaluate an infant for congenital syphilis
- infant has signs/symptoms of congenital syphilis
- mother not treated or txt not adequately documented
- mother txted with non-penicillin regime (only penicillin counts)
- mother txt w/n 30 days of child’s birth
- less than 4x drop in mother’s non-treponemal titre or not assessed or documented
- mother had relapse or re-infection after txt
What is the treatment of congenital syphilis during the neonatal period
proven probable disease:
IV crystalline pen G for 10 - 14 days
Asymptomatic but at risk based on maternal hx:
IV crystalline pen G for 10 - 14 days
Asymptomatic, mother adequately treated:
Close clinical follow-up
Can’t use IM in canada only IV b/c IM not good enough for CNS coverage
Key features of congenital toxoplasmosis?
Classic triad:
- hydrocephalus
- cerebral calcifications
- chorioretinitis
Symptomatic disease (15%)
- 1st and 2nd trimester infections
- macrocephaly, hydrocephalus, cerebral calcifications, seizures, cognitive impairment
- chorioretinitis, strabismus
- HSM, thrombocytopenia
Asymptomatic disease (85%)
- 3rd trimester infections
- untreated majority go one to have disease
- chorioretinitis most common manifestation
How do you dx and txt congenital toxo?
Dx:
-serology or PCR (CSF, blood, urine, tissue)
Txt:
- pyrimethamine + sulfadiazine + leucovorin x 12 months
- steroids for eyes/hydro
- +/- VP shunt
Congenital Zika Syndrome
Major features
- severe microcephaly with partially collapsed skull
- thin cerebral cortices, subcortical calcifications
- macular scarring, focal pigmentary retinal mottling
- congenital contractures
- infection in preg can be asymptomatic
- highest risk in 1st and 2nd tri
- antenatal dx: fetal u/s, amniotic fluid PCR
- postnatal dx: serology and PCR
GBS Early onset vs Late Onset disease
Early onset (< 7 days)
- vertical transmission
- pneumonia, septicemia, meningitis
Late onset (>/7 days)
- Vertical or horizontal transmission
- Meningitis, osteomyelitis, soft tissue infections, sepsis
Indications for intrapartum antibiotic prophylaxis
-positive GBS screen (35-37 wks)
- Unknown GBS status AND any of the following:
- previous infant with GBS
- GBS bacteriuria during current preg
- Delivery < 37 wks
- ROM >/18 hr
- Intrapartum fever (> 38)
- (Intrapartum nuclei acid amplification test positive)
Antibiotics for Intrapartum Proph
No allergy - penicillin or ampicillin
Mild penicillin allergy - cefazolin
Severe penicillin - clindamycin
-only penicillin/ampicillin considered adequate IAP
Low risk criteria for ferbrile infants 29 - 90 days
-previously health term infant
-non-toxic clinical appearance
-no focal infection (except OM)
-peripheral leukocyte count 5 - 15 x 10^9
-absolute band count 1.5 x 10^9
-urine 10 WBC/HPF
Stool (if diarrhea) < 5WBC /HPF
How do you dx and txt suspected HSV disease
Dx:
- culture/PCR/EM of vesicle fluid, nasopharynx, eyes, urine, stool, blood CSF
- Do LP even if clinical well (e.g. isolated mucocutaneous disease)
Txt: -IV acyclovir: isolated mucocutaneous disease: 2 weeks disseminated CNS disease: 3 weeks -suppressive oral acyclovir x 6 mon improves neurologic outcome for those with CNS disease
Long-term neurodevelopmental FU
Treatment for asymptomatic infant of mother with active HSV lesions at delivery
First episode; vaginal or c/s after ROM
- empiric acyclovir
- if swabs/blood + : full WU & txt
- if swabs/blood - : complete 10 days IV acyclovir
First episode; c/s prior to ROM
- empiric acyclovir not required
- if swabs/blood + : full WU & txt
Recurrent episode
- empiric acyclovir not recommended
- if swabs/blood + : full WU & txt
Length of txt for bacterial meningitis?
E coli: 21 days GBS: 14 - 21 days S. pneumonia: 10 - 14 days H. influ: 7 - 10 days N. meningitidis: 5 - 7 days
Treatment for Toxic Shock
- Empiric therapy with cloxacillin (or cefazolin) plus clindamycin for most cases
- penicillin + clinda +/- IVIG TSS due to GAS
- add vancomycin if MRSA is a concern
Pathogens in Asplenic children?
- strep pneumo = 50 - 90% of overwhelming post splenectomy sepsis
- Hib= rare due to Hib vaccination
- neisseria meningitidis = uncommon
- capnocytophaga canimorsus= dog saliva exposure
- slamonella spp = reptiles, food and water
What antibiotic prophylaxis can you use in aspelnic pts
Birth - 3 mon: amoxi-clav to cover for e.coli
>/ 3 mon: Penicillin (amoxicillin alternative) b/c s. pneumo for most
Cat Scratch Disease
- highest with those with kittens
- lymphadenitis (axillary most common)
- Perinaud oculoglandular syndrome ( granulomatous conjunctivitis unilateral with ipsilateral LN on the same side)
- hepatosplenic, neuroretinitis, encephalopathy
- FWOS
Treatment
- Azithro for lymphadenitis
- Doxy + rifampin for neuroretinitis/CNS disease
Clinical Manifestations of Lyme disease?
Early localized disease
- erythema migrans
- systemic symptoms (fever, myalgia, neck stiffness)
Early disseminate disease
- multiple EM lesions
- meningitis
- facial nerve palsy
- carditis
Late disease
- pauciarticular arthritis
- peripheral neuropathy
- CNS manifes.
Lyme Disease Treatment
Treat for 14 - 28 oral unless there is Carditis, meningitis or encephalitis/late manif (then txt with IV)
Oral:
Doxy for kids >/ 8
Amoxil
Cufureoxime
IV:
Ceftriaxone
Pen G
Prophylaxis:
-single dose of doxy for children > 8 following high risk exposure
List 5 ways to prevent mosquito/tick bites
Physical barrier:
- screen on window/doors
- fine mesh netting cribs/stollers
- long, loose fitted clothing, hat
Repellants
- DEET (10% or 30%) age cut of 12
- Icaridin for children 6 mon - 12 yrs
After outdoors:
- inspect skin daily for ticks
- shower/bath w/n 2 hours
What are the clinical symptoms of West Nile Virus?
Clinical presentation
- Asymptomatic (80%)
- West nile fever (20%)
- West nile neruological disease ( 1 %)
Neuro symptoms:
- Aseptic meningitis
- Encephalitis
- Acute flaccid paralysis
Complications of Chicken Pox
General
- pneumonia
- hepatitis, pancreatitis
- nephritis, orchitis
- thrombocytopenia
Bacterial infections
-cellulitis, abscess, Nec Fas
Neurologic -cerebral ataxia -encephalitis -reye syndrome -stroke zoster (Ramsay Hunt Syndrome)
What are the acute medical emergencies in the returned traveler
- malaria
- typhoid fever
- meningococcemia
- viral hemorrhagic fevers
if it’s a prolonged fever of delayed onset:
- TB
- Brucellosis
- Leishmaniasis
- Typhoid fever
Reasons for a reactive tuberculin skin test
- Mycobacterium tuberculosis infection
- Non-tuberculous mycobacteria infection
- BCG in past
- Incorrect technique (measurement)
Causes of false negative tuberculin skin test
- incorrect technique
- Active TB disease
- Immunodeficiency states
- Corticosteriods
- Young age
- Malnutrition
- Viral infections
- Live attenuated vaccines
Advantages of interferon gamma release assay over TST?
- more specific for M. tuberculosis than TST
- does not cross react with BCG and most non-tuberculous mycobacteria)
- does not require follow-up visit in 48 - 72 hrs
- most useful for diagnosis of LTBI in BCG recipients
limitations:
- cannot distinguish LTBI from active TB
- sensitivity decreased by temporary anergy of acute illness
- reduced sensitivity in immune compromised individuals
Who is at increased risk for TB?
-infants and post-pubertal adolescents (adolescents slow to come to care)
-recently infected (past 2 yrs)
-immunodeficiency states:
primary immunodeficiency
HIV
Malignancy
transplant
Immunosuppresive meds
Malnutrition
How to Dx Pulm TB
- TST& IGRA (but does not distinguish LTBI from active, and does not rule out pulm TB)
- CXR
- Gastric aspirates (3 x consecutive AM asp, before ambulation or feeding
- Bronchoalveolar lavage in select cases
- Microbiology (acid fast staining; culture; DNA probes; PCR)
Findings of Lung Imaging in TB
- Hilar adenopathy
- Miliary TB
- Ghon complex
TB Treatment
Latent TB
-Isoniazid x 9 mon
TB disease
- Start w/ 4 (INH, RIF, PYR, ETH)
- step down to 3 if fully sensitive strain
- 2 mon of 3 - 4 drugs then INH + RIF to complete course
Consider DOT
- Pyridoxine in selected cases (malnutrition, adolescents, pregnancy)
- Vit D usually given for children with TB
Preventing Vertical HIV Transmission
Antiretroviral therapy
- Triple ART starting in 2nd trimester
- IV zidovudine during labor
- Zidovudine to infant for 6 wks
- combination antiretroviral therapy may be warranted if mother’s VL elevated
- cotrimoxazole proph if HIV not reasonably excluded by molecular testing
- c/s if VL > 1000
- avoid breast feeding
How to confirm HIV status in exposed infants
- exclusion requires 2 separate negative PCR tests taken at >/1 and >/2 months of age
- HIV infection confirmed by positive PCR x 2 prior to 18 months or reactive serology after 18 months
Assessment of HIV infected child in ER
-clinical status
-Immunological status (CD4 & CD4 percent)
-Virologic status (viral load)
antiretroviral therapy and adherence
Immunizations in HIV infected children
- all routine
- live virus vaccines
- MMR should be given in absence of severe immune compromise
- VZB should be considered in asymptomatic children with CD4% > 25
- BCG & oral polio vaccine contraindicated in developed countries
- annual influ
- polysaccharide pneumococcal vaccine (after Prevnar 13)
- Meningococcal vaccine (Mentra, 4CMenB)
Hep A post-exposure management
- Hep A vaccine recommended as post-exposure proph w/n 2 wks of exposure in those >/12 mon of age
- for infants < 1, can give Hep A IG
- both vaccine and IG recommended for immunocompromised hosts
VZIG indications
- immunocompromised children w/o hx of varicella or varicella immun
- susceptible preg women
- newborn w/ mom who had VZV w/n 5 days before delivery or 48 hr post
- hosp prem >/28 wks whose mom lacks reliable hx of chicken pox or serologic evidence of protection against varicella
- hospitalized prem infant (< 28 wks or bw < 1000g) regardless of mom’s hx of varicella or varicella-zoster virus serostatus
-VZIG should be given as soon as possible w/n 10 days of exposure
Indications for palivizumab
- Children < 12 mon of age with CLD of prem who require ongoing med therapy at start of RSV season
- Children < 12 month w/ hemodynamically significant heart disease
- infants < 30 wks GA w/o CLD who are < 6 months at start of RSV season
- infants in remote communities and born at < 36 weeks GA if < 6 months at start of RSV
- consider full term inuit infants < 6 mon at onset of RSV season living in remote communities w/ persistently high rates of RSV hosp
- may consider children < 24 mon who are on home O2, have had prolong hosp for severe pulm disease, T21 or CF or severely immunocompromised
Who to screen for STI
Females
-all who are sexually active or victims of sexual assult
Males
- in the presence of risk factors including:
- Sexual contact with STI
- previous STI or pt in STI clinic in past
- new sexual partner or > 2 partners w/n past year
- IVDU/substance use
- unsafe sexual practices
- anonymous sexual partnering
- sex worker, survival sex, street involved
- time in detention facility
- sexual assault or abuse
Treatment of infant with mother who was untreated for gonorrhea or chlamydia
N. gonorrhea
Well appearing
-conjunctival culture
-IM ceftriaxone
Unwell
- conjunctival, blood and CSF cx
- consult ID with established disease
C. trachomatis
- routine cx, txt not recommended
- observe for conjunctivitis, pneumonia
Causes of lesions in labia minora
- HSV
- cysts or abscesses of the Bartholin glands
- Chancroid
- Bechet disease
- Trauma
- Genital warts
- Molluscum contageosum
- Syphilis, lymphogrnuloma, venereum, granuloma inguinale
Causes of facial nerve palsy in children
Idiopathic (bell’s palsy)
Infection related
- Otitis media
- Lyme diseases
- VZV (Ramsay Hunt Syndrome)
Tumors
- Cholesteatoma
- Facial nerve schwannoma
- Vestibular schwannoma, meningioma
Treatment for Facial nerve palsy
Bell’s palsy
- corticosteroids
- no benefit to antiviral therapy
Ramsay Hunt Syndrome
-antiviral + corticosteriods
Management of Febrile UTI (> 2 mon)
Majority can be txt with oral Abx
-cephalosporin, amoxi-clav, TMP SMX
Indication for IV
- toxic
- unable to take oral med
- immunocompromised
- Amp + Gent
- Abx for 7 - 10 days
- no proph generally after first febrile UTI
- Renal/bladder US after first febrile UTI < 2 yrs age
- VCUG not after first febrile UTI
Indications for VCUG
- U/S evidence of hydronephrosis, renal scarring or other findings suggestive of high grade VUR or obstructive uropathy
- recurrent febrile UTIs
Antibiotics for Prophylaxis in UTI
- only for grade IV - V VUR
- reassess after 3 -6 mon
- TMP SMX, nitrofurantoin first line
- if child has UTI due to organism resistance to these - consider stopping proph
- broad spectrum agents not recommended due to risk of infection with highly resistant org
When can you watch and wait for AOM
-child has to be >/ 6 mon
Non severe illness
- mild-mod TM bulge
- mildly ill, alert, mild otalgia, low grade fever (< 39)
- responding to antipyretics
other factors to consider
- no underlying other conditions of concern (immune def, chronic cardiac, pulm disease, anatomic abnormalities head/neck), hx of complicated OM, down syndrome
- parents capable of recognizing worsening disease, access to care
What is the length of treatment for the following bacterial meningitis?
GBS
Strep pneumo
Hib
N. meningitidis
GBS: 14 - 21 days
S. pneumo: 10 - 14 days
Hib: 7 - 10 days
N. meningitidis: 5 - 7 days
