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Microbiology ` microbiology—Virology Microbiology ` microbiology—Virology SEcTioN ii 171
Rabies virus Bullet-shaped virus A . Negri bodies Infection more commonly from bat, raccoon, and
(cytoplasmic inclusions B ) commonly skunk bites than from dog bites in the United
A
found in Purkinje cells of cerebellum and States; aerosol transmission (eg, bat caves) also
in hippocampal neurons. Rabies has long possible.
incubation period (weeks to months) before
symptom onset. Postexposure prophylaxis
is wound cleaning plus immunization with
killed vaccine and rabies immunoglobulin.
Example of passive-active immunity.
B Travels to the CNS by migrating in a retrograde
fashion (via dynein motors) up nerve axons
after binding to ACh receptors.
Progression of disease: fever, malaise
agitation, photophobia, hydrophobia,
hypersalivation paralysis, coma death.
Ebola virus A filovirus A that targets endothelial cells, Transmission requires direct contact with bodily
phagocytes, hepatocytes. Following an fluids, fomites (including dead bodies), infected
A
incubation period of up to 21 days, presents bats or primates (apes/monkeys); high incidence
with abrupt onset of flu-like symptoms, of nosocomial infection.
diarrhea/vomiting, high fever, myalgia. Can Supportive care, no definitive treatment. Strict
progress to DIC, diffuse hemorrhage, shock. isolation of infected individuals and barrier
Diagnosed with RT-PCR within 48 hr of practices for health care workers are key to
symptom onset. High mortality rate. preventing transmission.
Zika virus A flavivirus most commonly transmitted by Sexual and vertical transmission possible.
Aedes mosquito bites. Outbreaks more common in tropical and
Causes conjunctivitis, low-grade pyrexia, subtropical climates. Supportive care, no
and itchy rash in 20% of cases. Can lead to definitive treatment.
congenital microcephaly or miscarriage if
transmitted in utero.
Diagnose with RT-PCR or serology.
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