Exam #7: Zoonotic/ Exotic Viruses Flashcards Preview

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Flashcards in Exam #7: Zoonotic/ Exotic Viruses Deck (34):
1

What is a zoonoses?

Disease of vertebrate animals that can be transmitted to man
- Can be direct or through an insect vector

2

What is an arboviral disease?

Disease that has an insect vector i.e. arthropod borne viruses

3

What is the general lifecycle of the arboviruses?

- Bird natural host
- Mosquito intermediate
- Mosquito bites humans & infects

4

What is the most common arbovirus in the US?

West Nile Virus

5

What does WNV cause?

- Febrile illness
- Encephalitis in man & horses

~50% lead to encephalitis

6

When are WNV most commonly seen?

Summer-Fall when mosquitoes are most prevalent & people are outside

7

When has person-to-person transmission of WNV been seen?

- Blood transfusion & organ transplant
- Breast feeding

8

What is West Nile Fever?

A summertime flu-like illness seen in ~20% of those infected with WNV

*Most infections are asymptomatic

9

What percentage of the population develops WNV neurological disease? What patient population is this most common in?

<1% of individuals & mostly elderly

*Thus, the greatest risk factor for WNV encephalitis or noninvasive disease is age

10

How is WNV diagnosed?

History--WNV or other arboviral disease should be strongly considered in adults >50 years who develop unexplained encephalitis or meningitis in the summer or early fall

- CSF
- Serology

11

What is the treatment for WNV?

Supportive therapy

12

Is there a vaccine for WNV?

NOT in humans, but there is one for horses

13

What is St. Louis Encephalitis Virus?

- Prior to WNV, considered a major cause of arbovirus encephalitis in the US

14

How is SLE transmitted?

Mosquitoes

15

What symptoms are caused by SLE?

- Mild disease with fever & headache
- Severe disease with more typical meningitis symptoms, paralysis, and fatality

16

How is SLE prevented & supported?

No vaccine
Supportive treatment

17

What is Japanese Encephalitis Virus?

Leading cause of viral encephalitis in Asia

18

What are Eastern, Western, & Venezuelan Encephalitis Viruses?

Togaviruses/ alphaviruses

19

When is EEV most common?

Summer & fall, maybe precipitated by horse endemic

20

What are the symptoms of EEV?

Sudden onset fever
Myalgia
Headache
Seizures
Coma

21

How does WEV differ from the other arboviruses?

Most severe in young children instead of adults

22

What is LaCrosse encephalitis virus?

Bunyavirus (Hantavirus)

23

What is the unique feature of the Lacrosse encephalitis virus?

Most common in rodents & tree squirrels

24

Where is Rabies not seen?

Australia
Great Britain
Hawaii

25

How is rabies transmitted?

Via saliva of infected animals
- Bite
- Contamination of mucous membranes
- Aerosol
- Transplant

26

Describe the mechanism of action of Rabies.

- Inoculation
- Virus enters peripheral nerve & is transported to the CNS
- Flu-like symptoms
- Dissemination
- Behavioral change
- Hydrophobia
- Coma & death

27

How is Rabies prevented? How is it treated?

Vaccination of animals and high risk individuals (post-exposure prophylaxis & IgG)

28

How is Rabies diagnosed?

- Virus isolation or serology
- Negri bodies in infected neurons

29

What is LCMV?

Lymphocytic Choriomeningitis Virus

30

How is LCMV transmitted?

Inhalation of infectious aerosolized particles in rodent urine, feces, or saliva

- From common house mouse
- Person-to-person transmission has not been reported

31

What are the symptoms of LCMV?

Biphasic:
1) Febrile illness
2) Remission
3) Febrile illness

*Greatest concern in pregnant females

32

What are prion diseases?

Slowly developing neurodegenerative diseases that are thought to be caused by a family of viruses known as "slow viruses," now known to be caused by prions--small infectious proteins

33

List the prion diseases.

Kuru
CJD
GSS
FFI

34

What is the mechanism of prion disease?

Prions induce abnormal aggregation

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