Viral Agents of Bioterrorism Flashcards
Hemorrhagic fever
Acute febrile illness: malaise, myalgia, abnormalities in vascular permeability, bleeding manifestations…
But not volume loss is not the problem, more like widespread vascular damage.
Characteristics of viruses that cause viral hemorrhagic fever (VHF)
all are enveloped RNA viruses animal or insect host geographically restricted unpredictable outbreaks no real treatment
off label treatment for VHF
ribavirin is the first choice when faced with an unknown virus causing VHF.
(It is approved for Hep C)
What type of viruses are Ebola and Marburg?
Filoviruses (category A)
Characteristics of Filoviruses: Ebola and Marburg
enveloped, single-stranded, negative-sense RNA
branched or filamentous coiling around
5 subtypes of Ebola
cause disease in humans: Zaire, Sudan, Ivory Coast, Bundibugyo
cause disease in monkeys: Reston
Reservoir of Ebola
bats
Transmission of ebola
direct contact with blood/secretions of infected persons
infections are acute, no carrier state
Crimean-Congo Hemorrhagic fever (CCHF) is caused by what type of virus?
bunyavirus (category C)
Transmission of CCHF
transmission by ticks
genome of bunyavirus
genome is circular, ambisense RNA in three parts
What type of virus causes Lassa Fever and S. American hemorrhagic fevers?
Arenaviruses (category A)
characteristics of arenaviruses
genome has 2 strands of ambisense RNA
enveloped, grainy appearance (ribosomes of host)
What is the arenavirus reservoir?
rodent-borne disease
Symptoms of Lassa Fever
fever, retrosternal pain, sore throat, back pain, cough, abdominal pain, vomiting,, diarrhea, conjuncctivits, facial swelling, proteinuria, mucosal bleeding.
Hearing loss in 1/3 of cases, tremors, encephalitis
Where is Lassa Fever found
found in W. Africa because that’s where the multimammate rat is found
Lassa Fever is especially scary for
pregnant women - high risk of mortality and abortion.
transmits person to person really easily - everybody is dieing.
Lassa Fever Treatment
Ribavirin
Hendra and Nipah viruses are what type
henipaviruses (category C)
Henipavirus characteristics
enveloped virus with glycoprotein spikes
Hendra and Nipah virus clinical manifestations
severe respiratory disease (pneumonitis/multi-organ failure)
Acute Encephalitis
SMALLPOX virus characteristics
Large (seen by light microscope), brick-shaped particle.
Enveloped, dumbbell shaped core
Large, double-stranded DN
FUN FACT—only DNA virus that replicates in the cytoplasm
Smallpox disease manifestations: lesions and spread
all lesions develop at the same time (each lesion is same “age”), unlike chickenpox were the vesicles are at different stages.
spread by secretions from mouth/nose or from lesions
Smallpox diagnosis
stain smear with gentian violet, look for Guarnieri bodies
electron microscopy
egg inoculation - pock morphology on chorioallantoic membranes
