viral zoonoses I and II

Question 1

molluscum contagiosum

Answer 1

a poxvirus

wart-like lesions on face, butt, and back in kids

spread via towels/lockerrooms, contact, and sexually

self limiting after 4-6 months with secondary attacks

Question 2

Answer 2

molluscum contagiosum

Question 3

Answer 3

orf lesion

vessicular lesion caused by poxvirus of (ruminants) sheeps or goats, copox, or vaccinia

Question 4

vaccinia virus vaccination for _____ also immunizes against what rare poxvirus?

Answer 4

smallpox and monkey pox

Question 5

what animals can carry monkeypox?

Answer 5

african rodents (giant rat, prairie dogs)

Question 6

brickshaped (dogbone) organisms in cytoplasm

Answer 6

poxvirus

Question 7

rabies

Answer 7

rhabdovirus, envelped, negative sense ssRNA

ONLY virus shaped like a bullet

reservoirs = racoons, skunks, coyotes, and bats

causes acute encephalitis - fatal if untreated

Question 8

Answer 8

rabies

the only bullet-shaped virus

Question 9

Answer 9

negri bodies

eosinophilic cytoplasmic inclusion bodies

sign of RABIES!

Question 10

For persons who have never been vaccinated against rabies, post-exposure anti-rabies vaccination should always include administration of both ____ and ____

Answer 10

passive antibody (HRIG/human rabies immunoglobin) and vaccine

100% effective

Question 11

SARS coronavirus

Answer 11

SARS = severe acute respiratory syndrome

respiratory coronavirus

reservoir is bats

begins like a cold –> severe atypical pneumonia

xray resembles pneumonia or ARDS (acute respiratory distress syndrome)

***risks: travel to SE asia, lab/healthcare worker

Question 12

MERS-CoV

Answer 12

middle east respiratory syndrome coronavirus

carried in camels

Question 13

hendra and nipah viruses

Answer 13

paramyxoviruses

bats(carrier) to farm/domestic animals –> humans

BSL-4 restricted (same biosafety level as ebola)

symptoms –> causes widespread multisystem vasculitis (thrombosis, ischemia, and necrosis), pneumonitis and/or encephalitis

Question 14

2 filoviruses?

2 arenaviruses?

3 bunyaviruses?

Answer 14

Filoviruses = ebola and marbug

arenaviruses = lassa fever, S. american hemorrhagic fevers

bunyaviruses = CCHF (congo-crimean hemorrhagic fever), rift valley fever (RVF), and hantaviruses (HRFS and HPS)

Question 15

arboviruses and rodent borne viruses are all _________ and _____

one exception?

Answer 15

RNA viruses and enveloped

reovirus (colorado tick fever) is non enveloped

Question 16

Lassa fever

Answer 16

west africa; reservoir is multimammate rate (mastomys)

transmitted via animal urine and feces

symptoms = fever and malaise at day 10, + myalgia and prostration(exhaustion/lying), N/V/D/C/abdpain, cough, retrosternal pain

can cause deafness

Question 17

arenaviruses

virion appearance?

genome?

Answer 17

virions are enveloped with grain appearance d/t ribosomes from host cells

ambisense dsRNA (+ and - strands together; L and S)

—LCMV (lymphocytic choriomeningitis virus), lassa fever, and S american HFs

Question 18

LCMV

Answer 18

lymphocytic choriomeningitis virus

A biphasic febrile illness: Initial phase (a week) has fever, malaise, anorexia, aches, headache. A few days of remission, then….

Second phase: meningitis (fever, headache, and a stiff neck) or encephalitis (drowsiness, confusion, sensory disturbances, motor abnormalities, paralysis).

spread by the common house mouse, Mus musculus and hamsters.

Question 19

virus spread by mice/hamsters

Answer 19

LCMV

Question 20

hantavirus

Answer 20

rodent borne bunyavirus

enveloped ssRNA virus

genome has 3 negative sense RNA segments (L, M, and S)

transmission: inhalation of rodent excrement

HFRS = hemorrhagic fever with renal symptoms

symptoms = fever, headache, hemorrhage, and acute renal failure

Question 21

Answer 21

hanta virus

enveloped ssRNA virus

Question 22

hantavirus 2 diseases and their symtoms

Answer 22

HFRS = hemorrhagic fever with renal symptoms

symptoms = fever, HA, hemorrhage, and acute renal failure; capillary vasodilation, congestion with hemorrage

HPS (hantavirus pulmonary syndrome) = sin nombre virus in four corners area of US

–damage to capillaries in the lungs rather than kidneys

Question 23

vector for arboviruses?

Answer 23

insects

Question 24

arboviruses: compare genome and structure
1) bunyaviruses
2) reoviruses
3) rhabdoviruses

Answer 24

1) ssRNA 3 segments, enveloped, round
2) dsRNA 12 segments, NOT enveloped, round
3) bullet shaped ssRNA, enveloped

Question 25

colorado tick fever virus

Answer 25

a reovirus, no envelope, dsRNA, 12 segments vector = wood tick (spring to fall) in west/northwest pathogenesis = infects erythroid precursors; hemorrhagic disease when it infects the vascular endothelium diagnose by IF for viral antigen on blood smear symptoms = resembles dengue; incubation 3-6 days and then fevers, chills, headache, myalgia, athralgia, photophobia, and lethargy

Question 26

aedes mosquito transmits what two bunyaviruses

Answer 26

california encephalitis and La Crosse virus

Question 27

La Crosse virus

Answer 27

a bunyavirus transmitted by aedes mosquito causes pediatric arbovirus encephalitis in midwest states

Question 28

presentation of WEE/EEE/VEE

Answer 28

flu like can progress to encephalitis 3-10 days after infection usually resolves fine but can possibly lead to paralysis, mental issues, and death

Question 29

EEE WEE VEE

Answer 29

eastern, western and venezuelan equine encephalitis arboviruses (transmitted by insects or ticks) -- bird to mosquito to human only VEE can pass from horse to human they infect NERVOUS TISSUE

Question 30

VEE

Answer 30

transmission: appears to be rodents and mosquitoes, not birds Acute fever 2 – 6 days post-infection with pronounced systemic symptoms, neurologic involvement less common and less severe than with EEE/WEE, but again, more common in children

Question 31

WEE

Answer 31

mosquito-bird cycle Neurologic involvement more common in kids 60% of survivors with neurologic impairment.

Question 32

EEE

Answer 32

mosquito-bird cycle Neurologic involvement is lestimated at: ~1 in 23. death may occur in 3-5 days of onset of severe disease. Case/fatality rate ~50% among all age groups.

Question 33

three togaviruses (alpha viruses) transmitted by insects

Answer 33

EEE, WEE, VEE

Question 34

dengue

Answer 34

Symptoms: high fever, lymphadenopathy, myalgia, bone/joint pains, headache, and a maculopapular rash. Severe cases may present with hemorraghic fever and shock with a mortality of 5-10% (Dengue HF or Dengue shock syndrome) --\> usually in those previously infected with a different serotype = immunopathogenic mechanism No specific antiviral therapy is available. Supportive care. Prevention in endemic areas depends on mosquito eradication

Question 35

dengue transmission? what is facilitating global spread?

Answer 35

aedes mosquito air travel 4 serotypes --\> why vaccines are hard to create! \*\*the biggest arbovirus problem in the world today (SE asia, africa, A america, and carribean)

Question 36

yellow fever

Answer 36

west africa and s america 2 major forms: urban and jungle Jungle YF is the natural reservoir of the disease in a cycle of primates and forest mosquitoes. Humans incidentally infected upon venturing into jungle. Urban YF is transmitted between humans by the Aedes aegypti mosquito. symptoms = chills, fever, and headache, generalized myalgias and GI complaints (N+V). GI haemorrhage leads to “black vomit” and liver involvement causes jaundice. There is no specific antiviral treatment An effective live attenuated vaccine (17D) is available and is used for persons living in or travelling to endemic areas.

Question 37

japanese encephalitis

Answer 37

SE asia transmission involves culex mosquitoes, birds and pigs. Most subclinical: 1 in 300 develops a life-threatening encephalitis No specific therapy is available. Since Culex has a flight range of 20km, local control measures fail. An effective vaccine (killed virus) is available.

Question 38

west nile virus

Answer 38

flavivirus, +sense ssRNA transmission = culex mosquito; reservoir is birds causes ecephalitis, fever

Question 39

poxviruses exceptional features? vaccines? human diseases?

Answer 39

biggest virus only DNA virus that replicates in the cytoplasm there IS a smallpox vaccine

Question 40

hydrophobia/inability to drink water is a sign of

Answer 40

rabies! copious salivation too/drools to avoid swallowing