viral bio weapons

Question 1

viral hemorrhagic fevers (in general)

Answer 1

severe multisystem syndromes

the overall vascular system is damaged, and the body’s ability to regulate itself is impaired.

often accompanied by hemorrhage

Question 2

what kind of virus is Lassa fever?

Answer 2

arenavirus

Question 3

what kind of virus is CCHF (congo crimean hemorrhagic fever)

Answer 3

bunyavirus

Question 4

what kind of virus is ebola?

Answer 4

filovirus

Question 5

what kind of virus is yellow fever?

Answer 5

flavivirus

Question 6

what kind of virus is marburg?

Answer 6

filovirus

Question 7

what kind of virus is hantaviruses (HFRS and HPS)?

Answer 7

bunyaviruses

Question 8

properties of VHF agents (viral hemorrhagic fever agents)

Answer 8

all are enveloped RNA viruses dependent on animal or insect host

patient history includes: foreign travel, rural env, animal exposure

no cure or established treatment

Question 9

Leptospirosis

Answer 9

bacterial VHF vasculitis + hemrrhagic rash

d/t leptospira

with enlargement of spleen, jaundice and nephritis

Question 10

waterhouse-friderichsen syndrome

Answer 10

bilateral, hemorrhage into the adrenal glands caused by fulminant meningococcemia.

characterized by: (1) overwhelming bacterial infection (2) Rapid hypotension leading to shock (3) DIC (disseminated intravascular coagulation) with widespread purpura

Question 11

HUS

Answer 11

occurs after bloody diarrhea caused by E. coli O157:H7, a strain that expresses verotoxin (also called Shiga toxin).

Question 12

hemolysis –> dark urine “black water fever” is d/t…

Answer 12

falciparum malaria

Question 13

usually treatment for a VHF is based on

Answer 13

supportive care

Question 14

can maybe treat arenaviruses and bunyaviruses (CCHF, Hantaviruses, RVF) with

Answer 14

ribavirin

Question 15

what VHFs have vaccines?

Answer 15

yellow fever and argentine hemorrhagic fever

Question 16

how lethal is ebola virus?

Answer 16

up to 90%

Question 17

ebola and marburg

Answer 17

filoviruses

long, sometimes branched filaments, shorter filaments shaped like a “6”, a “U”, or circles.

they are enveloped ssRNA - sense

Question 18

likely reservoir of ebola?

Answer 18

bats in africa

Question 19

which ebola subtype is not pathogenic for humans?

Answer 19

reston type; the other four are!

Question 20

transmission/diagnosis of ebola

Answer 20

Infections are acute = no carrier state.

Transmitted by direct contact with blood and secretions of an infected person, and through contaminated needles etc.

Diagnosis: difficult in early stages because of non-specific early symptoms (e.g. red eyes and a skin rash).

Question 21

CCHF

transmission and vector

Answer 21

crimean congo hemorrhagic fever

transmitted by hyalomma tick

or contact with animal pre/post slaughter

-

Question 22

virus that causes CCHF

Answer 22

a bunyavirus

genome is circular, ambisense RNA (+ and -) in three parts - Small (S), Middle (M) and Large (L).

Question 23

Lassa fever and S. american hemorrhagic fevers (LCMV)

Answer 23

arenaviruses

rodent hosts

virions are envelped and have a grainy appearance due to ribosomes

genome has 2 strands of ambisense RNA (some + and some -; S and L)

Question 24

Lassa fever (arenavirus)

transmission

Answer 24

Contact with rodent (rats) excreta - contaminated food, broken skin, inhalation of tiny particles soiled with rodent urine or saliva (aerosol transmission)

virus is shed in the urine and feces

**can be rodent to human or human to human(body fluids)

Question 25

Lassa fever

Answer 25

caused by arenavirus Lassa Rodent reservoir –Mastomys (“multimammate rat)”

Question 26

signs and symptoms of lassa fever

Answer 26

Occur 1-3 weeks after infection Fever, retrosternal pain, _sore throat_, abdominal pain, vomiting, diarrhea, conjunctivitis, _facial swelling_, and mucosal bleeding. Neurological signs also seen Most common complication of Lassa fever (1/3 cases) is deafness.

Question 27

most common complication of lassa fever is

Answer 27

deafness

Question 28

swollen baby syndrome

Answer 28

lassa fever in infants ## Footnote Edema, Abd distension, & Bleeding = Poor prognosis Treatment: supportive care & Ribavirin

Question 29

A 50-year-old man from Sierra Leone who has been living in the US but went home for a week to visit his family, presents to your clinic with fever, chills and multiple joint pain. He informs you that he spent five days in his rural home village sleeping in a hut. There were rats running through the hut, and some dead rats on the floor. He tells you that his symptoms began on the day he flew back to New York city five days earlier. The patient receives symptomatic treatment and blood samples are taken. Considering his travel history and his symptoms the hospital staff suspect a viral hemorrhagic fever. By the fifth day after admission, conjunctival, nasal, and oral petechial hemorrhages are evident and three hospital staff and two other patients in the ward become ill with similar symptoms and one later dies. The traveler MOST LIKELY was infected by A. smallpox virus. B. yellow fever virus. C. a non-enveloped small DNA virus. D. Lassa fever virus. E. Dengue virus.

Answer 29

D ## Footnote Major clues: Traveler’s history; West Africa, along with clinical signs. Rural village with presence of rats/dead rats. Most likely ‘viral’ cause of his hemorrhagic fever is Lassa fever which is present in this location, has incubation period consistent with case (5 to 21 days) and is transmitted by rodents via aerosol/contaminated dust. Ans (A) is incorrect for many reasons such as smallpox has been eradicated and the patient recovered with no vesicular lesions; (B) and (E) are incorrect because both yellow fever and dengue are transmitted by mosquito vectors and this unlikely to occur in the NYC hospital. Ans (C) is incorrect because no small non-enveloped DNA virus is known to be associated with this disease scenario.

Question 30

poxviruses size? composition? genome? features?

Answer 30

Size: BIG brick-shape particle Genome (very large): Double-stranded, linear DNA. The only DNA virus that replicates solely in the cytoplasm Largest and most complex virus; resistant to inactivation

Question 31

poxvirus replication is under what type of regulation? how does this work?

Answer 31

temporal regulation ----- vaccinia virus RNA polymerase requires a separate set of virus-encoded proteins for the transcription of the early, intermediate and late classes of genes \*\*early mRNA creates early enzymes and intermediate transactivators; intermediate mRNA creates late transactivators and late mRNA

Question 32

small pox transmission

Answer 32

* Spread by secretions from mouth & nose and by pocks or scabs * Thus, transmission requires close contact with patients or their clothing or bedding

Question 33

a disfiguring disease?

Answer 33

small pox

Question 34

progression of smallpox rash

Answer 34

day 1 - a few papules/raised spots (2-4 days after a fever); seen first on the face then on the body day 2 - more papules; differ in size but same appearrance day 3 - beginning of vesicles (fluid accumulation and raised) day 4 - distinct vesicles; firm to touch; when broken dont collapse since fluid is in multiple compartments day 5 - flluid is cloudy and looks like pus; pocks are now called pustules; fever rises and feeling more ill day 7 - obvious pustules; all similar appearring; no mistake in diagnosis (picture shows day 4,5, and 7) day 8/9 - pustules are firm and embedded day10-14 - pustules dry up and dark scabs form; scabs contain LIVE smallpox virus; patient is infective until all scabs have fallen off day 14-20 - by day 20 all the scabs are off and light colored areas are observed; skin returns to normal over a week, however scars may remain for life

Question 35

when are smallpox patients infectious?

Answer 35

scabs contain LIVE smallpox virus; patient is infective until all scabs have fallen off

Question 36

where are lesions/pustules distributed in small pox?

Answer 36

face, palms/soles and extremities less dense on the trunk

Question 37

chicken pox vs small pox lesion distributions

Answer 37

in smallpox they are present on the palms and soles (denser on extremities) in chickenpox, they are NOT (denser on body, fewer on extremities)

Question 38

small pox diagnosis

Answer 38

gentian violet stain --\> Guarnieri bodies (typical inclusions). Electron microscopy --\> brick shaped virions.

Question 39

5 features that make a virus suitable for eradication

Answer 39

1. No animal reservoir. 2. Lack of recurrent infections. 3. One or few stable serotypes. 4. Availability of an effective vaccine. 5. Absence of subclinical infections.

Question 40

smallpox vaccine

Answer 40

made from vaccinia contains live virus; similar virus but doesnt cause smallpox can have bad side effects

Question 41

human vaccinia immune globulin (hVIG)

Answer 41

used to treat adverse reactions from vaccinia (smallpox vaccine)