Infectious Disease Flashcards
5-year-old unimmunized boy with H. influenzae meningitis. Has brothers who are 3, 10 and 16 years old, who are also not immunized. Who requires prophylaxis?
No prophylaxis indicated
All household members
All household members and hospital staff
Only the 3-year-old requires prophylaxis
All household members
5 groups eligible for RSV prophylaxis
• Born @ <30 wk GA and <6 months of life at start of season
• HD significant cardiac disease and <12 months of life
• BPD / CLD and <12 months of life, or <24 months if recent O2 needs
• Broader indications:
• Infants in remote communities who would require air transportation for hospitalization born before 36 + 0 weeks’ GA and <6 months of age at the start of RSV season
• Consideration may be given to administering palivizumab during RSV season to term Inuit infants until they reach six months of age
Who should be treated with prophylaxis after Hib exposure?
Chemoprophylaxis Recommended
For all household contacts in the following circumstances:
Household with at least 1 child younger than 4 years who is unimmunized or incompletely immunizedc
Household with a child younger than 12 months who has not completed the primary Hib series
Household with an immunocompromised child, regardless of that child’s Hib immunization status or age
For preschool and child care center contacts when 2 or more cases of Hib invasive disease have occurred within 60 days (see text)
For index patient, if younger than 2 years or member of a household with a susceptible contact and treated with a regimen other than cefotaxime or ceftriaxone, chemoprophylaxis at the end of therapy for invasive infection
Chemoprophylaxis Not Recommended:
For occupants of households with no children younger than 4 years other than the index patient
For occupants of households when all household contacts are immunocompetent, all household contacts 12 through 48 months of age have completed their Hib immunization series, and when household contacts younger than 12 months have completed their primary series of Hib immunizations
For preschool and child care contacts of 1 index case
For pregnant women
Routine vaccination recommended from 2 months til 5 years
Not needed after 5 years unless other health conditions as at decreased risk of invasive disease
3-year-old with otalgia, bulging and erythematous tympanic membrane. Fever for 5 days. Retroauricular swelling with anterior displacement of ear. How would you manage?
PO amox/clav
IV cefotaxime
IV vancomycin
PO azithromycin
IV cefotax
Mastoiditis–needs admission for IV 3rd gen cephalosporin
Strep pneumo most common bacteria.
CT scan of temporal bone to confirm diagnosis and CT head to identify intracranial complications.
Add Vanco if intracranial infection suspected.
What is the BEST agent to use for lice in a geographically resistant area?
Permethrin
Pyrethrin
Lindane
Resultz
Permethrin (Nix)
a. Permethrin—first line (however resistance documented)
b. Pyrethrin—first like (however resistance documented)
c. Lindane—not recommended due to absorption and risk of neurotoxicity and bone marrow suppression
d. Resultz—no resistance, isopropyl myristate 50% and ST-cyclomethicone 50%, approved for >= age 4
A pregnant woman develops varicella 7 days prior to delivery. What do you have to do for the neonate?
1 dose of VZIG IM
Acyclovir
VZIG + acyclovir
No therapy required
No therapy required
What are 3 potential interventions for post-exposure prophylaxis for people exposed to varicella?
Potential interventions for people without evidence of immunity exposed to a person with varicella or herpes zoster include:
(1) varicella vaccine, administered ideally within 3 days but up to 5 days after exposure;
(2) when indicated, Varicella Zoster Immune Globulin; or
(3) if the child cannot be immunized and Varicella Zoster Immune Globulin is not indicated, preemptive oral acyclovir or valacyclovir starting day 7 after exposure.
See photo for VZIG indications for exposed people:
16-year-old girl with nausea/vomiting, lethargy, myalgias. Strawberry tongue, diffuse maculopapular rash, conjunctivitis. BP 74/58, HR 170. What is the most likely organism?
S. aureus
Rickettsia rickettsiae
Borrelia burgdorferi
Neisseria meningitidis
S. aureus
- Superantigen toxin from S. aureus or other bacteria (eg. Group A strep)
- Overstimulates the immune system with nonspecific T cell binding
- Streptococcal TSS is most severe (highest mortality rate)
- Associated with retained tampon, surgical packing
- Skin findings: diffuse macular erythroderma (similar to sunburn) followed by desquamation 1-2 weeks after onset (palms and soles may be affected).
- High fever, hypotension
- Strep TSS may progress to nec fasc
- Diagnosis: In addition to hypotension ,at least 2 (Strep TSS) or 3 (staph TSS) organ systems must be affected for diagnosis. Perform bacterial cultures
Neonate with the following rash on their leg (exact picture). Looks well, afebrile with normal blood work (including septic workup and viral studies). Family history of hypopigmentation and dental anomalies. What is the diagnosis?
Incontinentia pigmenti
HSV
Eczema
Incontinentia pigmenti
11 year old girl with elevated ASOT, migrating arthralgia, fevers. She had a normal echo. You treat her with 10 days of antibiotics. How long does she need prophylaxis:
5 years
10 years
Prophylaxis until 18 years of age
No prophylaxis required
10 years
How long should you prophylax to prevent. rheumatic heart disease in person with GAS infection?
What do you prophylax with?
Length of treatment depends on echo findings
1) No carditis: 5 yrs or til 21 yrs of age, whichever is longer
2) Carditis, no valvulitis: 10 yrs or up to 21 yrs whichever is longer
3) Carditis with residual valve lesions: lifetime or up to 40 yrs of age
IM Penicillin q 3-4 weeks (can also do oral but not as practical)
18mo M with a verrucous lesion in his perianal region. He also has warts on his finger. Mom has no history of HPV. How did he get his perianal warts?
Heteroinoculation
Self-inoculation
Sexual abuse
Vertical transmission
self inoculation
4-year-old male with Staph aureus pneumonia, which progressed to lung abscess. He also had a history of pneumonia at 18 months of age. History of impetigo and mouth ulcers. Most likely defect?
B cell
Granulocyte
T cell
Complement
Granulocyte defect: abscesses, mouth ulcers, impetigo
8-week-old infant with cough, conjunctivitis and afebrile. CXR shows bilateral infiltrates. CBC normal apart from some mild eosinophilia. What is the treatment?
PO erythromycin
Amoxicillin
Reassure
Oseltamivir
PO erythromycin
Infants with chlamydial conjunctivitis or pneumonia are treated with oral erythromycin base or ethylsuccinate (50 mg/kg/day in 4 divided doses daily) for 14 days or with azithromycin (20 mg/kg as a single daily dose) for 3 days. Because the efficacy of erythromycin treatment for either disease is approximately 80%, a second course of therapy might be required. Data on the efficacy of azithromycin for ophthalmia neonatorum or pneumonia are limited. Clinical follow-up of infants treated with either drug is recommended to determine whether initial treatment was effective. A diagnosis of C trachomatis infection in an infant should prompt treatment of the mother and her sexual partner(s). Neonates with documented chlamydial infection should be evaluated for possible gonococcal infection. An association between orally administered erythromycin and azithromycin and infantile hypertrophic pyloric stenosis (IHPS) has been reported in infants younger than 6 weeks. Infants treated with either of these antimicrobial agents should be followed for signs and symptoms of IHPS.
Treatment of chlamydia in adolescents
For uncomplicated C trachomatis anogenital tract infection in adolescents or adults, oral doxycycline (100 mg, twice daily) for 7 days is recommended (see Table 4.4, p 898). Alternatives include oral azithromycin in a single 1-g dose, or levofloxacin (500 mg orally, once daily) for 7 days.
No test of cure needed, however test for re-infection advised at 3 months
4 month old baby referred because grandfather has cavitary TB. TST negative. What is your best next step?
Repeat TST in 8-10 weeks
Treat with isoniazid and rifampin
Fasting am gastric aspirates x 3
Repeat CXR in 4 months
Repeat TST in 8-10 weeks
(Would also initiate window prophylaxis however window prophylaxis is usually a single drug)
A 9 day-old neonate, born at 32 weeks who presented with a 24 hour history of increasing apneas. His mother was GBS positive and she did not receive prophylactic antibiotics. Blood cultures are positive at 18 hours and are growing gram-positive cocci in clusters. What is the most likely organism?
Staph aureus
GBS
Viridans group strep
Coagulase negative staph
Describe how each organism looks on gram stain and also E. coli on gram stain
CONS
staph aureus: gram positive clusters
GBS: gram positive chains
Viridians group strep: gram positive chains
CONS: gram positive clusters
E. coli: gram negative rods
3 year old boy and his father are having recurrent pinworm infections despite receiving mebendazole three times. His mother and sister are asymptomatic. How should you treat?
One dose of albendazole for dad and brother
Mebendazole with repeat at 14 and 28 days for everyone in the household
One dose of pyrantel for dad and brother
Depending on the version we think… or we’re remembering something wrong?? One of the following:
One dose of albendazole for the entire family
Treatment of the whole household with Pyrantel repeated at 14 and 28 days
Mebendazole at 14 and 28 days for whole house hold.
Red book:
Several drugs will treat pinworms (see Drugs for Parasitic Infections, p 949), including over-the-counter pyrantel pamoate and prescription mebendazole and albendazole. Mebendazole and albendazole are significantly more costly than pyrantel pamoate in the United States. Albendazole currently is not approved by the US Food and Drug Administration for treatment of pinworms.
Each medication is recommended to be given in a single dose and repeated in 2 weeks, because these drugs are not completely effective against the egg or developing larvae stages.
Because reinfection is common even when effective therapy is given, treatment of the entire household as a group should be considered. Repeated infections should be treated by the same method as the first infection. Vaginitis is self-limited and does not require separate treatment. “Pulse” treatment with a single dose of mebendazole every 14 days for a period of 16 weeks has been used in refractory cases with multiple recurrences
An unimmunized 3 year-old boy with presents with a 5 day history of low grade fever and has purulent nasal discharge. Culture was positive for H. influenzae. How do you manage?
Amoxicillin
Conservative
Azithromycin
Cephalexin
Amoxicillin
Uptodate:
Most infections caused by H. influenzae are treated empirically. In general, empiric regimens are designed to include an antibiotic that treats H. influenzae. Antibiotics that have activity against H. influenzae include beta-lactams (eg, amoxicillin, amoxicillin-clavulanate, or second- and third-generation cephalosporins), fluoroquinolones, macrolides, and tetracyclines.
Beta-lactams are generally preferred. Amoxicillin-clavulanate is a commonly used empiric treatment option for localized and non-life-threatening infections, such as otitis media, sinusitis, and acute exacerbations of chronic obstructive pulmonary disease. In patients with systemic infections, such as bacteremia or meningitis, ceftriaxone is the treatment of choice. (See ‘Ampicillin resistance’ below.)
A newborn has the following findings: mucocutaneous rash, hepatosplenomegaly, diffuse lymphadenopathy and osteochondritis. Which of the following congenital infections is most likely?
CMV
Syphilis
Rubella
Varicella-zoster
Syphilis
A 35+6 week neonate is born to a mother with fever at time of delivery. Her GBS status was unknown and she did not receive antibiotics. Rupture of membranes was 12 hours. What is the management?
CBC and observe for at least 24 hours if WBC >5
CBC and observe for at least 24 hours if WBC <5
CBC, blood cultures and treat with IV antibiotics for 36 hours
Reassure and discharge home with routine neonatal care
CBC and observe for at least 24 hours if WBC >5
what is considered adequate prophylaxis for GBS infection in neonates?
penicillin or ampicillin given at least 4 hours prior to delivery or cefazolin in penicillin allergic moms
clindamycin or vancomycin can also be used if mom has high-risk penicillin allergy but these are not considered adequate prophylaxis when treating baby
5 Maternal and neonatal risk factors for early onset bacterial sepsis in term infants
1) prolonged rupture of membranes >18 hours
2) maternal temp at time of delivery
3) curent GBS colonization
4) GBS bacturia at any point in pregnancy
5) previous infant with GBS infection
most common organism isolated in septic asplenic patients
strep pneumo isolated in at least 50% of cases
4 organisms other than strep pneumoniae isolated in septic asplenic patients
H. flu type B, Neisseria meningitides, salmonella species, Capnocytophaga from dog and cat bites
what antibiotic should apslenic patients be given after dog bite and what bacteria is it for
Capnocytophaga canimorsus, amox-clav
What extra vaccines should asplenic patients receive?
Pneumococcus: Prevnar-13 (PCV13), Pneumococcal polysaccharide vaccine (PPV23)
Meningococcus: Quadrivalent meningitis vaccine (MCV4) (Men A,C,W,Y).
Hib: All apslenic patients who have never received Hib Immunization or have missed one or more doses should be vaccinated age >= to 5 yrs.
Influenza
Salmonella: S typhi if travelling to developing country
What are 2 antibiotics that can be used for prophylaxis in asplenic patients? what antibiotic can be used if allergy? how long do they need to take them
PenV or Amoxicllin
Clarithromycin if allergic
Prophylaxis for all children <5 yrs of age AND for a minimum of 2 years postsplenectomy
What tropical disease are apslenic patients at increased risk for?
Malaria
Note: sickle cell protective against malaria, other aplsenic patients at risk for malaria
what antibiotic should be used in febrile asplenic patients?
Ceftriaxone +/- Vanco to treat strep pneumoniae
Nephrotic syndrome. Fever, ascites, abdominal distension. A peritoneal tap is done. What is the most likely organism?
Streptococcus pneumoniae
Escherichia coli
Enterococcus faecalis
Bacteroides fragilis
Strep pneumo
Gram negative bacteria also associated with many cases
A 3-year-old child has a history of a Streptococcus pneumoniae pneumonia and several episodes of otitis media. He has also had a previous infection with Giardia lamblia. What will give you the diagnosis?
Lymphocyte count
CH50
Respiratory oxidative burst
IgM, IgG, IgE and IgA levels
Immunoglobulin levels as giardia, strep pneumonia, and otitis media fit with B cell disorder
CH50–complement disorder
Respiratory oxidative burst–phagocyte defect
Lymphocyte count–T cell defect
How does chronic granulomatous disease/phagocyte defect present and what test do you use to diagnose?
Normal cell counts but inability of phagocytes to kill bacteria
Get recurrent abscesses throughout the body:
-cellulitis
-osteomyelitis
-gum abscesses
-GI/colitis
-upper and lower respiratory infections
Use respiratory oxidative burst to diagnose
2 month old male admitted with RSV bronchiolitis. He has moderate work of breathing and diffuse crackles and wheeze with decreased air entry at the right upper lung field on exam. He sats at 96% on 0.5L O2 and drops to 84% on room air. He is afebrile and feeding well. What is your management?
CXR
Supportive
Humidified high flow O2
Short-acting beta agonist
Supportive (CPS guideline and AAP no good evidence for HFNC)
A 4-year-old girl with fever, diffuse lymphadenopathy and hepatosplenomegaly. She has ulceration of her tonsils and oral mucosa. Her WBC is 25, Hg 100 and platelets 30.
Acute lymphoblastic leukemia
Lymphoma
EBV
Systemic JIA
Answer: Acute lymphoblastic leukemia—2 cell lines down, high WBC can be seen, overall very unwell
Lymphoma—usually large lymph node, less sick
EBV—usually asx in young
Systemic JIA—usually have high WBC, and high platelets (low or normal platelets should prompt evaluation for other diagnosis such as malignancy as per up to date, may have mild anemia. Overall sJIA is diagnosis of exclusion).
A 7 year old male with known hereditary spherocytosis presents with lethargy. His hemoglobin dropped from 100 to 40 and his retics are 1%. What is most likely to be responsible for this?
EBV
Parvovirus B-19
Coxsackie
***
Parvovirus B19
trigger of aplastic anemia (red cell aplasia), bone marrow freezes, no more production of retics and causes profound anemia
A 12 year old female with sickle cell anemia is going on a trip to South Asia. For which pathogens does her underlying disease put her at biggest risk?
Dengue
Typhoid fever
Hepatitis A
Tuberculosis
Typhoid fever–>Salmonella
A 3 year old male with 1 week of sore throat and cough. 4 days ago he started azithromycin, amoxicillin and tylenol. He now presents with the following rash.
What is the most likely cause?
Amoxicillin
Azithromycin / Tylenol?
Mycoplasma
HSV
(picture of crusty rash on lips, face, legs)
Mycoplasma—Mycoplasma pneumonia induced rash and mucositis (MIRM)—severe mucositis and rash preceded by prodome of cough, fever, malaise approx. one week prior to onset of their symptoms
Can also get rash if you give amoxicillin to a patient with EBV but it is diffuse maculopapular rash. Develops a few days after amoxicillin. Can develop into erythroderma.
Kid with resp symptoms, SpO2 92% on RA. CXR shows LLL consolidation. What do you treat with?
IV Ceftriaxone
IV Ampicillin
IV Vanco
IV C***
IV ampicillin
Once child with AO/SA has responded to IV antibiotics, which PO antibiotic should you switch them to?
Cephalexin (kingella resistant to Cloxacillin)
Cloxacillin if susceptive MSSA (however tastes bad)
Clinda, TMP-SMX, or linezolid if MRSA
A (child age) ***-year-old female presents with 3 days of pain at the distal tibia. CRP and ESR are elevated. MRI with gad confirmed osteomyelitis. What do you treat with?
IV cloxacillin
IV cefazolin
IV clindamycin
IV ertapenem (lol this probably wasn’t the antibiotic)
Answer: IV cefazolin. If MSSA is identified can subsequently narrow to cloxacillin or continue cefazolin; however K kingae is resistant to clox.
As per CPS statement:
Can treat with first-generation cephalosporin as most cases due to MSSA or Kingella kingae
K kingae is resistant to clinda, Vanco, and Cloxacillin
If unvaccinated and in area of invasive H flu should broaden to cefuroxime (2nd gen)
What are the indications for infant testing for cCMV?
1)Antenatal Indicators of risk:
a) Maternal CMV infection
b) Fetal ultrasound with findings suggestive of cCMV
c) Placental pathology consistent with CMV infection
2) Other indicators of potential risk:
HIV exposure
Primary immunodeficiency
3) Features consistent with symptomatic cCMV
4) A failed newborn hearing screen or confirmed SNHL
What does follow-up entail for cCMV patients? (monitoring and services)
Monitoring on treatment:
CBC/differential weekly x 1 month; every 2 weeks x 2 months then monthly x 3 months
AST, ALT, urea, creatinine monthly x 6 months
Follow-up
Audiology: Frequent tests in the first 2 to 3 years, then yearly until school age.
Testing frequency is determined by audiology based on results from previous testing.
Ophthalmology: Evaluate as soon as possible after cCMV is confirmed. Follow-up testing is based on initial findings.
Neurodevelopmental follow-up: Child should be followed closely in the first 2 years. Frequency of follow-up in first 2 years and thereafter should be determined by neurological concerns and initial assessment.
Dental: Enamel hypoplasia
Vestibular dysfunction: OT
Mom is anti-HCV positive and + Hep C PCR positive. Baby is now 6 months old. Baby Anti Hep C antibody negative. What investigation do you do now?
If neg at 6 months, too early but will always be neg, reassure
If positive at 6 months, too early may be mom’s antibodies so repeat
A-Hep C PCR
B-Retest Hep C antibody at 12-18 months
C- no further investigations
No further investigations
If neg at 6 months, will always be neg, reassure
If positive at 6 months, too early may be mom’s antibodies so repeat
Who qualifies for home RSV prophylaxis.
a. 2mo with cystic fibrosis
b. 4 mo ex 31+6 wk without chronic lung disease
c. 9 mo ex 33+6 wk with chronic lung disease requiring home O2
d. Born 30-32 weeks
9 month ex 33 wk infant with chronic lung disease requiring home O2
C Diff treated with PO Flagyl. Now recurred with 5> stool and positive toxins (2 months later), c diff positive. What to do?
A- Observe
B- PO Flagyl
C- PO Vanco
D- IV flagyl, PO vanco
PO flagyl
Relapse does not mean drug resistance. After first recurrence repeat regimen used for initial treatment. For second recurrence use Vanco.
For severe disease treat with PO Vanco.
For mild, discontinue precipitating antibiotics, follow-up, no abx.
Moderate disease treat with flagyl.
