Viral Infections Flashcards
Herpes
What leads to flare ups?
Flare ups May follow minor infections, trauma, stress, or sun exposure.
HSV 1
In US alone, HSV 1 is more common for oral and genital ulcers in young females
positive serology very common
HSV 2
Most common cause of genital ulcers in developed world
Most in US unaware infected
HSV
Where do lessons form? And what’s their patho?
Skin or mucous membrane
vesicle changing to painful ulcer over several days
may have prodrome of pain
Suppressive tx reduces transmission and Sx
HSV
What is Herpes simplex ophthalmicus? Epithelial vs stomal?
HSV infection in the eye
Lesions limited to epithelium should heal well
Stromal involvement can cause uveitis, scarring, and blindness
HSV
What are complications of infection? (4)
- Meningitis
- Ocular disease (herpes keratitis)
- GI disease
- Pneumonia
what is Ocular disease (herpes keratitis)?
Branching (dendritic) ulcers that stain with fluorescein in the iris
HSV
How do we treat?
Acyclovir 400-800mg 3x a day for 10 days
Trifluridine for eye infection
what are signs and symptoms of VZV?
(chicken pox) fever, malaise, abd pain 1-2 days before rash
rash successive crops, lesions in different stages, crusted 4-7 after onset
contagious until all lesions pop and are crusted over
pitted scars are frequent
VZV
Varicella-zoster virus (VZV) aka human herpesvirus (HHV)-3 may manifest as
varicella (chickenpox) or herpes zoster (shingles)
Varicella
How do you describe the rash for chicken pox
“dew drop on a rose petal”
Varicella
What are complications of chicken pox? (4)
skin infxn, pneumonia, encephalitis, death
Varicella
What is the Tx for chicken pox?
Treatment with acyclovir 20mg/kg (Max 800mg) orally for 7 days within 24 hours of dx if Age > 12 years, Secondary household contacts (tends to be more severe), chronic cutaneous and cardiopulm disease, children using long term salicylates (risk for Reye’s syndrome-neurologic condition)
Immunocompromised patients
Varicella
Congenital varicella risks for fetus
when mother is infected while pregnant
Spontaneous abortion, chorioretinitis, cataracts, limb atrophy, cerebral cortical atrophy, neurological disability
Varicella
What is the mortality rate of neonatal varicella?
30% mortality
Herpes zoster
Shingles Rash
tingling, pain, eruption of vesicles in a dermatomal distribution, evolving to pustules and then crusting
epstein barr
how long does someone remain infectious?
up to 6 months after symptom onset
Epstein barr
how long is incubation
30-50 days
epstein barr
pathophys
(heterophile antibodies)
Primary EBV infection of B lymphocytes induces circulating antibodies directed against viral antigens
EBV
Lifelong infection
can have latency with periodic reactivation with oral shedding (often w/o shedding)
EBV
Malignancy Complications
Insufficient cellular immune responses may result in EBV-induced malignancy (Hodgkin lymphoma, Burkitt lymphoma)
EBV
Signs and symptoms
- Abrupt onset severe sore throat/pharyngitis withposterior cervicallymphadenopathy
- Gradual onset low-grade fever,malaise,arthralgia, andmyalgia
- Splenomegaly in 2nd and 3rd weeks
- Abdominal pain/discomfort
- Hepatomegaly rarely clinicallypalpable
- Elevation of liver transaminases common
- Hoagland sign (transient upper lid edema)
EBV
Mono rash
Morbilliform rash
affects <15% of pts
More intense and extensiverash in up to 90% of patients 2–10 days afterantibiotics- happens when Dr thinks they have strep, then pt thinks they’re allergic to penicillin
EBV
what are life threatening complications? 6
Rare but potentially life-threatening complications:
severe upper airway obstruction
splenic rupture
fulminant hepatitis
encephalitis
severe thrombocytopenia
hemolytic anemia
CMV
Cytomegalovirus what disease? Transmission?
very common, also causes mono.
by age 5 30% are infected
transmitted by close contact, sexual, occupational, perinatal (in utero, during birth, breast milk)
CMV
Complications
Retinitis, GI/hepatobiliary, pneumonitis, neurologic syndromes
CMV
Congenital CMV complications, Dx, Tx?
long-term neurodevelopmental disabilities: sensorineural hearing loss, cerebral palsy, intellectual disability, vision impairment, seizures
Test urine or saliva
Treat with ganciclovir/valganciclovir
Rotavirus
causes what disease? What age group?
viral gastroenteritis, particularly in children between 2-6y
rotavirus
3 factors that play a role in rota diarrhea
- loss of brush border enzymes
- the direct effect of the rotavirus enterotoxin NSP4
- activation of the enteric nervous system
rotavirus
signs and symptoms
N/V/watery nonbloody diarrhea and fever
rotavirus
severe signs and symptoms of rotavirus? Tx?
dehydration, seizures, and death can occur.
Treatment: supportive care
Flu
what are the most common groups?
A and B
C rarely results in illness
Flu
Complications
DM, Heart failure, pulm disease, chronic disease – renal, hepatic, hematologic, or neurologic
more severe in obese pts
flu
incubation period
1-4 days
flu
clinical presentation
Fever, chills, diaphoresis
Fever less common in children and elderly
Myalgia
Headache
Malaise and fatigue
Anorexia
Rhinorrhea and nasal congestion
hacking nonproductive cough
Sometimes GI symptoms (N/V/D) in kids, rarely in adults
Tachycardia
If fever or dehydrated
Cervical adenopathy (posterior)
Lungs are typically clear.
Sore throat, non-exudative
Flu
Dx (2)
1.Rapid molecular assays with nasal swab
2.PCR testing
Flu
Tx
supportive care
if caught w/in 2 days
oseltamivir, zanamivir, peramivir
Flu
who do we Tx with antivirals?
Children <2 years and adults ≥65 years
Pregnant women and within 2 weeks postpartum
immunocompromised
Flu
when to admit? ICU?
Admit if severe illness/moderate illness w declining function:
Pregnant women, Children <5 & Adults ≥65
ICU admission if:
Rapidly declining respiratory function/hypoxia
Bilateral diffuse pneumonia
hemodynamic instability
Flu
Pregnancy- special population risks? When can can you vax?
Increased risk for hospitalization but not mortality
Increased risk for pre-term birth or sGA(small for gestational age) infants
VACCINATE during any trimester
If suspected or confirmed case, treat
Consider post-exposure chemoprophylaxis
within 48 hours of exposure
COVID
COVID incubation
<14 day incubation
40% asymptomatic
COVID
complications 5
Respiratory failure
Cardiovascular
Thromboembolic complications
Neurologic complications
Inflammatory complications
Covid
treatment
Nirmatrelvir-ritonavir (paxlovid) must be given w/in 5 days of symptoms
Rabies
Rhabdovirus encephalitis
Transmission? Incubation?
spread through saliva
incubation 3-7 weeks depending on distance of wound from CNS, may be years!
Rabies
pathophys
virus travels in nerves to brain, multiplies in brain, then migrates along efferent nerves to salivary glands
rabies
non-specific prodrome
Pain at infection site
Fever, malaise, Headache, Nausea/vomiting
Aerophobia (skin temperature change sensitivity)
Abnormal sexual behavior
Males-frequent ejaculation, Priapism
Females-hypersexuality
Rabies
CNS stage- incubation, Sx
begins 10 days after prodrome
Encephalitic (80%) “furious”
Classic rabies symptoms
Delirium alternating with periods of calm
severe laryngeal or diaphragmatic spasms and sensation of choking (hydrophobia)
hypersalivation, lacrimation, sweating, dilated pupils
Paralytic (20%) “dumb”
paralysis ascends, onset of dense paraplegia with loss of sphincter tone; paralysis of swallowing and respiratory muscles, leading to death.
rabies
treatment
Rabies vaccine four iM injections in deltoid (anterolateral thigh muscles in children) on days 0, 3, 7, and 14 after exposure)
notify public health
Poliomyelitis- how many types, where is it endemic?
3 wild serotypes. eliminated from 99% of world. endemuc in Nigeria, Pakistan, Afghanistan
Abortive Polio
Nonspecific & mild over 2-3 days
Fever, ha, vomiting, diarrhea/constipation, and sore throat
Nonparalytic poliomyelitis
Nonspecific symptoms as above
Signs of meningeal irritation (neck stiffness, irritability, PE findings)
muscle spasms without paralysis
polio
paralytic poliomyelitis
Flaccid asymmetric paralysis, mostly proximal mm of LE
Sensory loss is rare
2 types
Spinal poliomyelitis (spinal nerves)
Bulbar poliomyelitis (cranial nerves, respiratory and vasomotor centers)
polio
Post-poliomyelitis syndrome symptoms
Progressive muscle limb paresis, mm (muscle mass) atrophy, fasciculations and fibrillations during rest activity
Restless leg syndrome
Ebola
mortality/pregnancy, transmission and incubation
Zoonotic transmission to humans occurs via contact with the reservoir or infected primate
Fruit bat possible reservoir
2-21 days, RNA peaks 7 days into illness
Mortality rate 70% in endemic areas
pregnant female mortality 86%
Ebola
Signs and Symptoms of nonspecific febrile illness
Up to 1 week
Fever, HA, dizziness, weakness, fatigue, myalgias, and arthralgias
Ebola
Signs and symptoms 3-5 days in
Abdominal pain, severe n/v, and diarrhea
for an additional week
During this period, neurologic symptoms begin
Confusion, slowed cognition, agitation, occasional seizures
Hypovolemic shock
1-5% hemorrhagic issues
GI bleeding, diffuse mucosal bleeding, conjunctival bleeding
Ebola
Dx
IGM or PCR test
ebola
Treatment
Supportive
Iv fluids may decrease mortality rate to <50%
No approved meds
Arbovirus
include which visuses and how are they transmitted
Togavirus
flaviviruses-west nile, dengue, zika
orthobunyaviruses
alphaviruses
mosquito and ticks
arboviruses
West Nile Virus
Incubation
Time
Is it reportable?
leading cause of domestically acquired arboviral disease in US
must report
Mid July to sept
incubation is 2-14 days, only 10% develop symptoms
West nile virus
Neuroinvasive Symptoms signs and mortality rate
10% progress to neuroinvasive disease
Meningitis, encephalitis, asymmetric acute flaccid paralysis (like polio)
3-15% mortality rate
Fever, AMS (altered mental status), seizures, tremors, cranial nerve palsies
Nonpruritic maculopapular rash (not required)
West Nile Virus
Complications of infection (3)
Bronchial pneumonia
Retinopathy (24%)
Renal infection
Virus may show in urine for up to 6 years
Risk to develop chronic renal disease
West Nile Virus
Diagnostic testing
IgM for West nile virus in serum or csf typically + once symptomatic
Igm in csf = neuroinvasive disease
OR
4x increase in baseline igg titer
West Nile Virus
treatment
no specific antiviral therapy
supportive care
avoid mosquitos
Dengue fever
transmission and incubation
via mosquito
7-10 days
dengue
Febrile Phase
high fever, facial flushing, malaise, retroorbital eye pain, arthralgias, sore throat
Maculopapular rash
Most patients recover and fevers resolve by day 8
Severe dengue
Plasma leakage
Increased liver size, vomiting, severe abdominal pain
Hemorrhage
Ecchymosis, GI bleeding, epistaxis
organ involvement
Hepatitis, encephalitis, myocarditis
dengue
Shock
Decreased level of consciousness, hypothermia, hypoperfusion leading to metabolic acidosis, organ impairment, DIC, AKI
Dengue
Dx
IGM and IGG ELISA after febrile phase
Dengue
Immunization who is eligible
only for children 9-16yo with prior hx of infection living in endemic area
Tx for polio
Supportive
Paralytic polio should be hospitalized w physiotherapy
fifth disease
Nonspecific Prodrome Sx
low grade fever, coryza, headache, nausea, diarrhea
Low grade fever = above 98.6° F (37° C) but below 100.4° F (38° C)
fifth disease
Sx
Classic “slapped cheek” rash [erythematous malar rash with relative circumoral pallor] 2-5 days after prodrome; followed several days later by reticular rash on trunk and extremities
fifth disease
incubation
14 days
can be contagious before rash is visible
fifth disease
when are school epidemics likely
late winter/early spring
fifth disease
pathogen
Erythema infectiosum
Parvovirus B19
fifth disease
Phase 1
“slapped cheek” appearance – abrupt onset
fades in 2-4 days
fifth disease
Phase 2
Erythematous macules
~1-4 days
fades to Reticular ~5-9 days
Fifth disease
phase 3
Clearing and recurrences of rash over weeks/months due to: exercise, stress, overheating, bathing in hot water
fifth disease
Tx
Usually reassurance and symptomatic treatment
Immunocompromised patients (HIV): maybe IV IG
fifth disease
effects on congenital
30 - 40% of pregnant women are seronegative for B19V and susceptible to infection
Fetal effects include spontaneous abortion, anemia, intrauterine fetal death
fifth disease
immunocompromised complications
Parvovirus B 19 infection in immunosuppressed patients can result in chronic red cell aplasia/anemia
Rubeola
what disease does it cause
Measles
Rubeola- measles
transmission and incubation
by direct contact with infectious droplets or by airborne spread
1-2weeks
Rubeola- measles
Prodrome
3 C’s
7-18 days after exposure fever,** coryza, cough, conjunctivitis,** malaise, irritability, photophobia, Koplik spots (small irregular, and red with whitish center on the mucous membrane)
rubeola- measles
Rash
brick red, maculopapular; appears 3–4 days after onset of prodrome; begins on face and proceeds “downward and outward,” affecting palms and soles last
Pinhead size papules → coalesce to a brick red, irregular, blotch maculopapular rash → spreads to trunk and extremities, including palms and soles
Rash lasts for 3-7 days
Fades in order of appearance
Rubeola- measles
when is pt infectious
highly infectious 4-5 days before and after rash shows up
rubeola - measles
Dx
Classic presentation, clinical diagnosis
Serum for measles IgM antibody
throat/nasopharyngeal swab or urine for viral culture
Diagnosis unlikely if patient vaccinated and does not have typical symptoms
Public Health reporting
Rubeola - measles
Tx
Supportive care
Infants <1 year should have IM immunoglobulin
Isolation for 4 days from onset of rash
Rubeola - measles
congenital Sx
Not known to be teratogenic, but associated with spontaneous abortion, premature labor, low birth weight
Mumps
Transmission, incubation
resp droplets, 1/3 are aSx
12-25
mumps
Sx
Painful, swollen parotid glands overlying facial edema
Frequent involvement of testes, pancreas, and meninges in unvaccinated individuals
mump
Dx
Clinical diagnosis usually sufficient
Serum IgM for mumps
mumps
Tx
supportive, usually brief illness
Topical compresses
isolation
Mumps
congenital disease
unlikely
Rubella
what is Rubella
Rubella is a systemic disease caused by togavirus transmitted by inhalation of infective droplets
Rubella
incubation
14–21days
Rubella
Promdrome
No prodrome in children
mild prodrome in adults (fever, malaise, coryza)
Rubella
Sx
symptoms coincide with rash or precede rash by up to 5 days
Posterior cervical and postauricular lymphadenopathy 5–10 days before rash
Fine pink maculopapular rash of 3 days duration; face to trunk to extremities over 2-3 days
Rubella
Dx and Tx
Cannot make dx based on single igm isolation (cross reactivity with other viral infx)
supportive
rubella
congenital infection
Congenital rubella infection: hearing loss, developmental delay, growth retardation, cardiac and ophthalmic defects.
2015: WHO announced Americas region is world’s first to eliminate rubella and congenital rubella syndrome.
Roseola infantum
incubation & Sx
9-10 days after exposure
3-5 days of high fever (may exceed 40°C [104°F]) that resolves abruptly, followed by rash
roseola
rash
Morbilliform rash, starting on the neck and trunk and spreading to the face and extremities (cephalad and centrifugal spread)
Mostly children under age 2, usually benign and self-limited
hand foot mouth
incubation & transmission
3-5 days
direct contact with skin, nasal/oral secretions of infected individuals, or fecal contamination.
blisters infective until they have dried up, usu. few days.
stools infective for up to a month.
hand foot mouth
typical infection
Flat pink patchesondorsalandpalmarsurfaces of hands and feet; progression to small, elongated greyish blisters; within a week, blisters peel off leaving no scars.
Smallvesiclesandulcersin and around mouth, palate,pharynx. sometimes painful, so child eats is fretful and eats poorly. (inside oral cavity – enanthem)
Redmaculesandpapuleson buttocks and sometimes arms, genitalia.
hand foot mouth
atypical Sx
Widespread red,crustedpapules; no blisters or very large ones; subsequent skin peeling and/ornailshedding; unusual sites such as ear
In children withatopicdermatitis, lesions may select skin affected byeczema(eczema coxsackium).
Hand foot mouth
complications
Dehydration
Fingernail/toenail changes (2 months after infection)
Transverselines
Nail shedding (onychomadesis)
Eventuallynailsreturn to normal.
Serious infection:
Enteritis
Myocarditis
Meningoencephalitis
Pneumonia
hand foot mouth
pregnancy comlications
Pregnancy: spontaneous abortion or fetal growth restriction
Monkeypox
incubation,
reportable?
13 days
yes
monkeypox
Signs and Sx
Lad
Fever
Rash
Well circumscribed lesions all in same stage of development
monkeypox
Dx and Tx
Elisa, PCR, viral culture
No standardized treatment regimen
Cidofovir (vistide)
