Infectious Disease Flashcards
Fever without source
fever of one week or less
history, physical, labs don’t show source
Fever of Unknown Origin (FUO)
Fever for at least 8 days
history, physical, labs don’t show source
PNA triad
tachypnea + high fever+ cough
Rigors
sudden feeling of cold, shivering, rise in temp, sweating
-higher probability of SBI
-can indicate serious non-bacterial
-dengue, malaria, chikungunya
Localizing signs of SBI in Children
- lethargy, irritability, change in mental status
- tachycardia disproportinate to degree of temp elevation
- tachypnea or labored respirations
- bulging or depressed anterior fontanel
- nuchal rigidity
- petechiae
- localized erythema, tenderness, or swelling
- abdominal or flank tenderness
- fever
risk factors for occult bacteremia
- 36 mts or younger
- > 39.5 C or 103.1F
- WBC ≥ 15,000 or ≤ 5,000
- total band cells ≥1500
- ESR ≥ 30 mm/hr
- underlying chronic disease (malignancy, immunodefeciency, sickle cell, malnutrition)
- clinial appearance (irritability, lethargy, toxic appearance)
Diagnostic work up: ≤90 days
Fever criteria- 100.4 or higher
CBC w/ diff, cath urine, blood/urine culture, CRP, procalcitonin
if ≤29 days or if concerns- lumbar puncture
stool studies/ culture- if diarrhea
WBC alone not reliable, viral PCR can be helpful but don’t stand alone
chest x ray if respiratory sysmptoms- tachypnea, hypoxia, rales, wheezes, increased WOB
Diagnostic work up: 3-36 mts
3-24 mts- 102.2 w/o clear source
24-36 mts- 103.1 w/o clear source
- if not at increased risk, at least 2 doses of prevnar PCV12- do not need blood testing
- if at increased risk because unimmunized, unknown vaccine status, or 1 dose prenar- may need screen eval w/ CBC, blood and urine cx
infants w/ temp >102.2
- urine testing- females < 2, uncircumcised < 1 yr, circumcised < 6 mts
infants w/ temp >103.1 & WBC > 20,000- chest x ray to detect occult pna
Diagnostic work up: > 36 mts
- lab eval dependent on H&P
- work up for chronic disease - sickle cell, cancer, immunodeficiency, nephrotic syndrome, cardiac transplant
- children w/ CP- higher chance of UTI
- chidlren w/ CF- increased risk of respiratory infection
- cognitive impairment- higher chance of LRT d/t decreased ability to clear airway
Common organisms for SBI/ Occult Bacteremia- ≤ 3 mts
E coli
Group B strep
streptococcus pneumoniae
listeria monocytogenes
salmonella (> 1 mt)
haemophilus influenzae type b (> 1 mt)
Common organisms for SBI/ Occult Bacteremia- 3-36 mts
s. pneumoniae
neisseria meningitidis
salmonella
staphylococcus aureus
HIB
Meningitis
Inflammation of the meninges
CSF -elevated protein count, low glucose
Meningitis Etiology 2 weeks
Group B Strep
E Coli
Enterococcus
Listeria monocytogenes
Meningitis Etiology 3-6 wks
group b strep
HIB
Streptococcus pneumoniae
Neisseria meningitides
E. coli
Listeria monocytogenes
Meningitis Etiology 7 weeks-15 yrs
HIB
Streptococcus pneumoniae
Neisseria meningitides
Meningitis etiology > 15 yrs
Streptococcus pneumoniae
Neisseria meningitides
streptococcus
Meningitis clinical signs
hyper/hypothermia, jaundice, hepatomegaly, lethargy, poor feeding, vomiting
bulging fontanel in 1/4 - late onset, rarely nuchal rigidity
Meningitis - early onset
- first 5 days, death rate 20-50%
- acquired at delivery
- typically secondary to septicemia from maternal infection (vertical transfer)
- e coli or GBS
Meningitis-late onset
- after 5-7 days, death rate 20%
- post natal symptom onset
- e coli, GBS, enterococci, gram negative enteric bacilli (i.e klebsiella), listeria moncytogenes
Meningitis treatment- newborn
- ampicillin & aminoglycocide (gentamycin) or cefotaxime
- +/- acyclovir
- older than 1 week - vancomycin + gentamycin
- treat for 2 weeks at least beyond sterile CSF (typically 14-21 days)
- sequelae: hydrocephalus, CP, epilepsy, cognitive impairment, deafness
Erythema Infectiosum (fifth disease) etiology, transmission, incubation
parovirus B19
respiratory route, blood, blood products
incubation 4-28 days
Parovirus clinical manifestations
- prodromal phase - LGF (15-30%), HA, Mild URI
- Rash (afebrile)- hall mark characteristic
- begins w/ facial flushing (slapped cheek)
- spreads to trunk and extremeties as diffuse macular erythema
- central clearing- lacy, reticulated appearance
- waxes & wanes for 1-3 wks
- can recur w/ exposure to sunlight, heat, exercise, stress
Erythema Infectiosum complications
- arthropathy - more common in adults and older adolscents after infections, joints most affected are hands, wrists, knees, ankles
- transient aplastic crisis - increased risk for sickle cell pts
- immunocompromised pts at risk for chronic infection- chronic anemia, neutropenia, thrombocytopena, or complete bone marrow suppression, treated w/ IVIG
- primary maternal infection associated w/ fetal hydrops and IUFD
Erythema Infectiousum diagnosis/ differentials/ treatment
Diagnosis
- typically based on clinical symptoms
- antibody testing available, usually not done in peds
- PCR testing
Differntials
-rubella, measles, enterovirus infections, drug rx
arthralgias- JRA, SLE
Treatment- symptomatic
Acute Herpetic Gingivostomatitis s/s
s/s: pain in the mouth, salivation, fetor oris, refusal to eat, fever (up to 104-105F)
fever & irritabiltiy precede oral lesions by 1-2 days
mouth lesions are vesicular, which rupture and are covered by a yellow-gray membrane, which sloughs into ulcer
Acute Herpetic Gingivostomatitis treatment
Acyclovir PO 15mg/kg/dose given 5x/day x 7 days
(start w/i 72 hrs of onset)
Herpetic Whitlow
HSV infection of minor trauma around the nail
Painful, deep seated spreading lesions w/ vesicles
resolve spontaneously in 2-3 wks
Treat w/ acyclovir PO
Herpes Simplex Virus diagnosis
two of the following:
- clinical picture
- isolation of the virus
- development of specific antibodies
- demonstration of characteristic cells, histologic changes, viral antigen or HSV DNA in scarapings, CSF, or biopsy material
HSV treatment
dosing dependent on indication
Acyclovir 10-15mg/kg/dose q8hr
Varicella- Zoster Disease etiology/transmission
Etiology: varicella-zoster virus (herpesvirus)
Transmission:
airborne or direct contact
contagious 24-48 hrs before rash and until vesicles are crusted
10-21 day incubation period
Varicella Rash
Prodrome 24-48 hrs before rash: fever (100-102), malaise, anorexia, headache, mild abdominal pain
Rash begins as erythematous macule (flat) → papules (raised) → clear, fluid filled vesicles (dew drop on a rose petal)
- fluid becomes cloudy, then crusting
- lesions appear in different stages
Varicella diagnosis
Diagnosis:
based on clinical presentation
CBC- leukopenia in first 72 hrs → lymphocytosis
PCR & antibody testing available
Varicella Zoster treatment
uncomplicated varicella- symptomatic treatment only- treat itchiness, fever, discourage scratching
acyclovir PO 20mg/kg/dose q6hrs x 5 days - should be initiated w/i 24 hrs
acyclovir IV 500 mg/m2 q8hr (for severe disease or immunocompromised)
Varicella complications / prevention
complications: bacterial infections, encephalitis, cerebellar ataxia, pna
prevention:
isolation rooms w/ filtered air systems
vaccine- 12 mts, 4-6 yrs
Varicella post exposure prophylaxis
Immunocompromised children, pregnant women, and newborns exposed to VZV:
varicella zoster immune globulin (VZIG)
Healthy children:
administer vaccine within 3-5 days of exposure
Breakthrough Varicella
- occurs in previously immunized child at least 42 days after vaccination
- rash is more likely to be non vesicular
- typically mild fever w/ less than 50 lesions
- still infectious
Progressive Varicella
complication of varicella in immunocompromised children, pregnant women, newborns
visceral organ involvement, coagulopathy, severe hemorrhage, continued lesion development
Herpes Zoster
(shingles)
vesicular lesions clustered within dermatomes
in children, rash is mild, acute neuritis is minimal
in immunocompromised- more likely adult form w/ post herpetic neuralgias
Herpes Zoster treatment
Acyclovir PO -if less severe dx
Acyclovir IV (500mg/m2 or 10mg/kg q8hr)- immunocompromised
EBV/ Infectious Mononucleosis transmission
caused by epstein barr virus, transmitted in oral secretions
shed in oral secretions for > 6 mts after acute infections, then intermittently throughout life
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Infectious Mononucleosis clinical manifestations
- incubation period of 30-50 days- prodrome usually lasts 1-2 weeks
- classic presentation: low grade fever, sore throat, exudate on tonsils, fatigue
- some patients may just have lymph node swelling or fever/chills and fatigue
- splenic enlargement occurs in first few weeks
- epitrochlear lymphadenopathy
- prognosis: major sx last 2-4wks, fatigue may wax and wane
Infectious Mononucleosis diagnosis
presence of typical symptoms
confirmed by serology:
- CBC- leukocytosis w/ elevated monocytes and lymphocytes
- heterophile antibody (monostat) -rapid antibody test (detects antibodies in 50% of cases in children < 4)
- EBV titers- IgM peaks early, IgG peaks midway or later in acute phase
Infectious mononucleosis treatment
- r/o strep pharyngitis
- rest & symptomatic therapy (APAP/iburpofen for sore throat & HA)
- avoid contact sports and strenuous athletic activities during first 4 weeks or while hepato/splenomegaly present
Infectious Mononucleosis complications
(rare)
- splenic rupture- usually during 2nd wk of dx
- airway obsturction- most common cause of hospitilization- IV hydration, humidified air, steroids, consider emergency T&A
(very rare)
- guillain barre syndrome, reye syndrome, hem olytic anemia, aplastic anemia
Roseola
(sixth disease or exanthema subitum)
- viral infection caused by human herpesvirus 6 (HHV-6) or HHV-7
- spread through contact w/ infected saliva or through air (cough/sneeze)
- not contagious after 24 hrs of being fever free
Roseola clinical picture
prodrome either asymptomatic or w/ mild respiratory symptoms
clinical illness:
- high fever (37.9-40C, 101-106F), irritability, anorexia
- persists for 3-4 days, then fever resolves abruptly
- after fever resolves, rash appears- small pink lesions beginning on the neck and spreads to trunk and extremities, lasts 1-3 days
- resolves spontaneously
Roseola rash
after fever resolves → rash appears small pink lesions beginning on the neck and spreads to trunk and extremities
lasts 1-3 days, resolves spontaneously
Roseola diagnosis/treatment
diagnosis- based on clinical presentatino
treatment- sympotmatic
infections in immunocompromised- can be severe; pneumonitis and encephalitis
Influenza clinical manifestations
- Abrupt onset of coryza, conjunctivitis, pharyngitis, and dry cough
- Systemic signs include high fever, myalgia, malaise, headache
- In younger children, illness may isolate to a small area of the respiratory tract (i.e pharynx) and fever may be higher (104-105F)
- Fever typically last 2-4 days and respiratory complaints may persist up to 1 week
Complications- OM & PNA most common
Influenza Diagnosis
Usually based on clinical presentation
Diagnostics:
- Rapid influenza testing
- Viral culture
- CBC- leukopenia
- CXR- atelectasis or infiltrate in 10% of children
Influenza Treatment
typically sympotmatic
antivirals for young children or severe disease
Oseltamivir (tamiflu)
- infants 3mg/kg/dose BID x 5 days
- fixed dosing for older children
- longer duration for severe illness
influenza high risk for complications/ recommended for antiviral therapy
- children < 2yrs
- Chronic diseases: asthma, sickle cell, metabolic disorders (DM), neurologic and deurodeveloment conditions (CP, epilepsy), mod to severe developmental delay, muscular dystrophy, immunosuppresion
Measles (Rubeola) clinical manifestations
- pathognomonic- Koplik’s spot- on buccal mucosa, erythematous base with whitish/grey blue lesion on top
- Plus: fever, cough, conjunctivities, rash
Complications: tracheitis, PNA, AOM, CNS involvement (rare)
Measles treatment
- supportive care for most, isolation
- abx for bacterial superinfection
- hospitilazation for severe dx
- close monitoring & reporting required
SARS CoV-2 AAP Guidelines
**Asymptomatic or mildly symptomatic **(< 4 day fever, short duration of myalgia, chills, and lethargy)
- No exercise until cleared by physician
- Look for chest pain, SOB out of proportion for URI, palpitations, syncope
Moderate symptoms (≥4 day fever, myalgia, chills, lethargy or non ICU hospital stay)
- ECG and cardiology consult
**Severe symptoms **(ICU stay or MIS-C)
- Restricted activity 3-6 mts until cleared by cardio
COVID treatment
- Supportive care
- Glucocorticoids (dexamethasone) +/- tocilizumab if required HFNC or higher level respiratory support
- Empiric abx if indicated
- Consider thromboprophylaxis
Consider (severe illness)
- Antiviral therapy - remdesivir, usually 5 days (28 days and older) or Paxlovid
- Janus kinase inhibitor- baricitinib
- Monoclonal antibody therapy- bamlanivimab-etesevimab (< 2 yrs)
Hydroxychloroquine not recommended
Post Acute Sequelae of COVID (PASC/ Long COVID)
- Defined as the presence of one or more new, persistent physical symptoms, which may fluctuate and relapse, that lasts at least 12 weeks after confirmed initial SARS-CoV-2 infection and** impairs daily function**
HIV
selectively infects and destorys CD 4 T lymphocytes
CD4 T lymphocytes stimulate production of other immune cells to fight infection, results in immunodeficiency
HIV - Mother to Child Transmission (MTCT)
- intrauterine
- intrapartum
- postnatal (breastfeeding)
How to prevent:
- test pregnant women
- treat HIV infected women w/ ARV drugs during pregnancy and at delivery
- electice c-section
- no breastfeeding
- treat infant w/ ARV drugs after delivery
Antiretroviral Prophylaxis
Zidovudine 2mg/kg/dose q6hr or 4mg/kg/dose q12hr
Monitor: CBC (causes bone marrow suppresion- anemia, neutropenia)
Clinical presentations that warrant HIV testing
- PCP pneumonia
- Recurrent, severe, and/or persistent oral thrush
- Recurrent bacterial infections
PNA
Sinusitis
OM - Failure to thrive or poor growth
- Recurrent parotitis (inflammation of parotid gland), lymphadenopathy, chronic interstitial lung disease (Lymphocytic interstitial pna /LIP)
- TB infection
- Shingles during childhood
- Flu like or mono like symptoms, and not improving
HIV testing in infancy
< 18 mts - virologic assay- HIV RNA or DNA nucleic acid tests (NAT)
(not HIV antibody test
p24/IgM/IgG sensitive
HIV 1/2 antigen/antibody combination immunoassay
Immunosuppression
< 12 mts: ≥ 1500 (normal), < 750 severe
1- < 6: ≥ 1000 (normal), <500 severe
≥ 6 yrs: ≥ 500 (normal), <200 severe**
No live vaccines if severe immunosuppression
PCP prophlaxis for >1 w/ severe immunosuppression, all <12mts
Lyme Disease etiology
Borrelia burgdorferi - spirochete found in deer ticks
Lyme stages
Early localized stage (7-14 days after bite)
- flu like symptoms and erythema migrans (asymptomatic, flat, erythematous patchy w/ peripheral expansion, central clearing)
- lymphadenopathy
Early disseminated stage (3-5 wks after bite)
- multiple EM, intermittent arthralgias, peripheral neuropathies (facial nerve)
Late stage (wks-mts after bite)
- arthritis & neruological disease
Possible symptoms: HA, hearing loss, paralysis of face, muscle soreness, fever, chills, fatigue, heart complications, N/V
Lyme diagnosis/treatment
Diagnosis- lyme titer
Treatment:
- remove tick
< 8 yrs:
amoxiciilin 50mg/kg.day TID x 21 days
cefuroxime 30 mg/kg/day BID
> 8 yrs
doxycycline 4mg/kg/day BID
Prevention: DEET, early removal of tick
Rocky Mountain Spotted Fever etiology
rickettsia rickettsii (dog & wood ticks)
Rocky mountain spotted fever clinical manifestations
Prodrome:
- H/A (prominent feature, many be severe)
- GI symptoms, malaise, myalgias
Fever, rash, headache (classic triad)
- rash on day 3-5
- peripheral erythematous blanching macules and papules spread centrally. evolves into petechiae and purpura
RMSF lab findings
Titers
CBC:
- left shift ( (increased immature neutrophils, indicates inflammatory process or infection) w/ low to normal WBC
- thrombocytopenia
LFT abnormalities
