Emerging Viruses I and II

Question 1

Hantavirus

1. mortality rate
2. family
3. Virus name
4. Disease
5. Reservoir
6. Distribution

Answer 1

1. high, 50-67%
2. Bunyavrirdae
3. Sin Nombre
4. Pulmonary syndrome- pneumonia
5. deer mice
6. N. America

Question 2

Hantavirus

1. genome
2. what is seen on X-ray?
3. Transmission
4. Treatment
5. Detection

Answer 2

1. negative strand, segmented RNA
2. diffuse infiltrate
3. inhalation of virus particles present in mouse feces and urine; NOT human-human
4. aggressive respiratory support
5. specific IgM in pt serum

Question 3

Arboviruses

1. Which viruses are transmitted by mosquitoes or ticks?
2. Which viruses are transmitted by animals or animal bites?

Answer 3

1. Togaviridae, Flaviviridae, Bunyaviridae, Reoviridae

2. Arenaviridae, Rhabdoviridae, Filoviridae

Question 4

4 Major Cycles by which arboviruses are transmitted

Answer 4

1. insect, bird, insect –> man (dead end host) or horse (dead end host)
2. Insect, monkey, insect, man, insect, man (urban cycle)
3. inset, goat, insect, goat, man (via goat milk); man is dead end host
4. insect, bird, insect, rodent, man (dead end host); also shows transovarial transmission in mosquitos

Question 5

Arbovirus induce 3 infections

Answer 5

1. Encephalitis (fever, headache, stiff neck, altered consciousness)
2. Rash-fever (fevers, headaches, myalgias, arthralgias, malaise; resolve w/o sequelae
3. Hemorrhagic fevers (undifferentiated/rash fever + profuse bleeding into the skin and GI tract secondary to DIC, hypotension, shock, and leukopenia

Question 6

Arbovirus Pathogenesis

Answer 6

1. Infects vascular endothelium
2. virus also infects macrophages in liver in spleen
3. virus can infect liver and brain –> serious disease

Question 7

Detection of Arbovirus infection

1. How hard is it?
2. Why?
3. What methods can you do?

Answer 7

1. very difficult
2. don’t grow well in cell culture
3. specific diagnosis by RT-PCR or by serology (high IgM or increasing IgG)

Question 8

Eastern Equine

1. Geographical Distrubtion
2. Age Group Affected
3. Mortality
4. Sequelae
5. Symptoms

Answer 8

1. East, Gulf Coast, South
2. Children
3. 50-75
4. 80% of survivors- neuro symptoms
5. headache, altered consciousness, seizures (fulminant)

Question 9

St Louis

1. Geographical Distrubtion
2. Age Group Affected
3. Mortality
4. Sequelae
5. Symptoms

Answer 9

1. Cental, West, South
2. Adults > 50 y/o
3. 2-20
4. 20% of survivors
5. headache, nausea, vomiting, disorientation, stupor, irritability

Question 10

LaCrosse

1. Geographical Distrubtion
2. Age Group Affected
3. Mortality
4. Sequelae
5. Symptoms

Answer 10

1. Central, East
2. Children
3. <1
4. Low
5. seizures, paralysis, focal weakness

Question 11

Yellow Fever Virus

1. Family virus
2. genome; envelope?
3. vector
4. reservoir
5. transmission cycle

Answer 11

1. Flaviviridae
2. • ssRNA, envelope
3. mosquitoes
4. monkeys in jungle, humans for urban cycle
5. jungle cycle

Question 12

Yellow Fever

1. Geographic Distribution
2. Therapy
3. Vaccine

Answer 12

1. Endemic in equitorial areas (south america/Africa)
2. no antiviral therapy
3. Live-attenuated vaccine is effective; travelers should be vaccinated

Question 13

Dengue Virus

1. family
2. genome; envelope?
3. vector
4. reservoir
5. cycle
6. serotypes?

Answer 13

1. Flaviviridae
2. • ssRNA, envelope
3. mosquitoes
4. monkey
5. jungle cycle
6. several, infection with one serotype seems to predispose individuals to more severe disease

Question 14

Dengue Fever

1. Geographic areas
2. What causes the severe infection in secondary disease?
3. Disease (2)

Answer 14

1. central/south americas; subsaharan africa, india and south pacific; now seen in US
2. immunoresponse causes increased capillary leakage leading to more vascular permeability
3. “breakbone fever”: headache, fever, pains in joints, muscles, eyeballs, maculopapular eruptions persisting 3-4 days
4. Dengue hemorrhagic fever- severe hemorrhage or shock; most frequently seen in children

Question 15

Dengue Fever

1. Lab Diagnosis
2. Vaccine

Answer 15

1, depends on day of illness, viremia or NS1 (early); IgM or IgG later (secondary infection or late primary infection)
2. development of live-attenuated, tetravalent vaccine is ongoing

Question 16

West Nile Virus

1. Family
2. genome/ envelope
3. Vector
4. reservoir
5. who gets most significant disease?

Answer 16

1. Flaviviridae
2. +ssRNA; envelope
3. mosquitoes
4. marsh birds; humans- urban cycle
5. people over 50 y/o

Question 17

West Nile Virus

1. How is it detected in US?
2. What diseases does it cause? (2)
3. Vaccine

Answer 17

1. Sentinel Crows, RT-PCR analysis of mosquitoes, monitor cases of encephalitis
2. Meningoencephalitis, fever
3. In development

Question 18

St Louis Encephalitis Virus

1. Family
2. genome/ envelope?
3. Vector
4. reservoir
5. Treatment
6. Vaccine

Answer 18

1. Flaviviridae
2. +ssRNA, envelope
3. mosquitoes
4. marsh birds; man can be reservoir for urban cycle
5. no specific therapy
6. no specific vaccine

Question 19

Eastern Equine Encephalitis Virus

1. Family
2. genome/ envelope
3. Vector
4. reservoir
5. what is man?
6. What is horse?
7. Vaccine?

Answer 19

1. Togaviridae
2. +ssRNA, env
3. mosquitoes
4. marsh birds;
5. dead end host w/ 50-70% mortality (short viremia)
6. dead end host?
7. none for man, available for horses

Question 20

California Encephalitis Virus

1. Family
2. genome/ envelope
3. Vector
4. reservoir
5. What disease can it cause
6. what is man?

Answer 20

1. bunyaviridae
2. • segment RNA, envelope
3. mosquitoes
4. small mammals
5. CNS disease due to secondary viremia
6. dead end host

Question 21

California Encephalitis Virus

1. what is another virus in the family?
2. who tends to get it?
3. how is it detected?
4. Therapy
5. Prevention
6. what kind of transmission is present?

Answer 21

1. LaCrosse Virus
2. children
3. serology
4. none
5. no vaccines; use mosquito control
6. transovarial transmission

Question 22

Colorado Tick Fever

1. Family
2. genome/ envelope
3. Vector
4. reservoir
5. Symptoms
6. What does it look similar to? How is it different from that?

Answer 22

1. Reoviridae
2. segmented, double stranded RNA; no envelope
3. tick bite
4. squirrels
5. fever, headache, myalgia, rash, not severe
6. Lyme disease; different geographical distribution

Question 23

Omsk Hemorrhagic Fever/ Spring-Summer Hemorrhagic fever

1. what kind of transmission?
2. reservoir
3. vector
4. prevention

Answer 23

1. cycle 3- transmitted through goat milk
2. small mammals or goats,
3. ticks
4. Vaccine, used in Austria; needs to be used in E. Europe and Russia

Question 24

Characteristics of Filoviruses

1. What do they cause?
2. Reservoir
3. Therapy/Vaccines

Answer 24

1. severe hemorrhagic fevers with high mortality
2. bats
3. not available, in development

Question 25

Ebola Virus 1. Family 2. genome/ envelope 3. Vector 4. reservoir 5. Transmission

Answer 25

1. Filoviruses 2. negative strand RNA virus 3. monkey 4. bat 5. Blood-blood transfer: usually bush hunters dressing a monkey that they killed will be exposed/infected

Question 26

Severe Acute Respiratory Syndrome 1. Family 2. What contributed to rapid spead? 3. Vector 4. reservoir 5. Transmission

Answer 26

1. Coronavirus; related to but distant from other coronaviruses 2. international travel 3. Masked Palm Civets 4. chinese horseshoe bat 5. Respiratory spread, large droplets, close contact; may spread via fecal-oral

Question 27

Nipah 1. what is seen in cell culture? 2. virus family? morphology? 3. reservoir 4. vector 5. Transmission

Answer 27

1. multinucleated giant cells 2. paramyxovirus w/ helical nucleocapside 3. bats 4. pigs 5. not person-person (including family contacts and health care workers); result of close contact with sick pig/horses

Question 28

Nipah 1. Symptoms in pigs 2. Pathology in pigs 3. How was virus controlled? 4. Overall lesson

Answer 28

1. rapid/labored breathing; explosive "mile long" nonproductive cough; neurologic changes (lethargy and aggressive behavior) 2. pulmonary infiltrate and linear staining of the bronchial epithelium 3. culling the pigs 4. viruses can emerge into the human population through intermediate hosts