Arboviruses

Question 1

Arboviruses are

Answer 1

a group of viruses that are transmitted by ARTHROPOD VECTORS, and are RNA VIRUSES

Question 2

All of the VHF virsues are

Answer 2

RNA viruses

Question 3

Arbovirsues can produce what four syndromes? HEFS

Answer 3

1. Systemic febrile illness (Chikungunya, O’nyong-nyong, Ross River, dengue)
2. Fever with arthritis (chikungunya, Ross River, O’nyong-nyong)
3. Encephalitis (Jap, West Nile virus, Murray Valley, Eastern Equine, Western equine)
4. Hemorrhagic Fever (Yellow, Dengue, Rift Valley Fever, chikungunya)

Question 4

The mosquito uses its ______ for feeding, and much of the virus would be concentrated in the _______

Answer 4

proboscis; salivary gland

Question 5

64 year old white guy presents in August with fever, headache, mental status changes and neck stiffness. Patient didn’t travel outside of NY state, and lives near Cicero swamp. CBC done shows leukopenia. Lumbar puncture shows WBC is high with lymphophilila, high protein, and low glucose. What are you considering?

Answer 5

Eastern equine encephalitis (would have inflammation and edema in the thalamus)

Question 6

For EEE, list the family, the genus, and the four types of viruses in this genus.

Answer 6

Family: togaviridae;
Genus: alphavirus
Type: positive ssRNA
alphavirus contains: EEE, WEE, VEE, Everglades

Question 7

Where are the four alpha virus types endemic? Clinical manifestations? List prob of developing encephalitis and mortality for three of them

Answer 7

EEE: Eastern USA;
WEE: Western USA;
VEE: South and North America;
can vary from inapparent to influenza-like illness to syndrome of encephalitis; highest for EEE and lowest for VEE;
5% WEE, 35% VEE, 50% EEE

Question 8

64 year old white guy presents in March with fever, headache, mental status changes, and neck stiffness. He had gone to Thailand 2 weeks before illness and also lives near Cicero swamp. Lab values were like the same in that other 64 year old dude. What does this guy have and what other lab test would be of interest?

Answer 8

Japanese encephalitis; look at the MRI for zat inflammation and edema

Question 9

For JE, list family, virus type, and where you could find the virus

Answer 9

Family: flaviviridiae
Type: positive ssRNA
Location: think Asia!!!

Question 10

For JEV, list the vector, timing of infection, and hosts, both natural and accidental

Answer 10

Vector: culex tritaeniohynchus (culex mosquitos);
Timing: feeds at night and seen during rainy season;
Natural host: pig (can amplify the titer) and migrating birds/domestic fowl;
accidental: humans and horses

Question 11

Where is JEV increasing?

Answer 11

Nepal and India

Question 12

List the spectrum of the disease for JE and what’s the prognosis?

Answer 12

Spectrum: febrile headache can progress to aseptic meningitis and lastly ENCEPHALITIS; POOR!!!

Question 13

Is there a vaccine for JE?

Answer 13

YES!! can give two doses 28 days apart (IXIARO)

Question 14

For yellow fever, what are three ways you can react to the vaccine?

Answer 14

1. Immediate hypersens or anaphylactic reactions
2. YF vaccine-associated neurologic disease
3. YF vaccine-associated viscerotropic disease (begins 3-5 days after vaccination)

Question 15

For yellow fever, list the family and genus, and how did it even get into the US?

Answer 15

Family: flaviviridiae;
genus: flavivirus;
West African lineage that came to Caribbean via slave trade and later to US!!!

Question 16

Host for yellow fever? What is the vector?? Big clinical features for yellow fever?

Answer 16

Non-human primate host (e.g. Africa and South America);
Aedes!!
Hemorrhagic phase (coffee-ground hematemesis, melena, metorrhagia, petechiae, ecchymoses) as well as volume depletion, renal failure!! Preceded by mild nonspecific febrile illness

Question 17

56 year old woman comes to hospital with a week of fever, headache, myalgia , and maculopapular rash. Travel history includes Key West, and she has petechiae on her chest wall, arms, and soles of feet. Labs show hemoconcentration, leukopenia, and low platelets. What diagnosis do you suspect and what can make the diagnosis definitive?

Answer 17

Dengue fever, with IV fluids

Question 18

For dengue, list genus, family, vector, and the serotypes. What is significant about there being these serotypes?

Answer 18

Genus: flavivirus
family: flaviviridae;
vector: aedes!!
DEN-1, -2, -3, -4 (infection with one serotype protects you against one, but still vulnerable to the other three; upon SECOND INFECTION, more likely to get hemorrhagic disease)

Question 19

For dengue, what does the vector prefer to feed on?

Answer 19

Aedes prefers to feed on humans

Question 20

Dengue is going ______, and what country is having more of these cases?

Answer 20

global; THAILAND!!!

Question 21

Clinical manifestations of dengue? What is the hallmark for the extreme case?

Answer 21

Can go from febrile illness to severe hemorrhagic fever; you can see petechiae (like a kid with a blood pressure cuff, gastric bleeding, melana);
PLASMA LEAKAGE!!

Question 22

What is the most common arbovirus?

Answer 22

Dengue!!!