Arboviruses

Question 1

What are the common characteristics of arboviruses

Answer 1

Fever + Encephalitis and/or arthritis and/or hemorrhage

Question 2

arbovirus principle reservoir, vector

Answer 2

Vertebrate animals (usually small mammals or birds) but sometimes in epidemics, humans (though usually dead end hosts)
Mosquito is vector

Question 3

Sylvatic cycle

Answer 3

primate reservoir, transmitted by forest mosquitos

Question 4

emergence cycle

Answer 4

humans infected by sylavatic mosquitos, passed to urban

Question 5

urban cycle

Answer 5

human reservoir, transmitted by urban mosquitos, sedes aegypti

Question 6

clinical presentation of chikungunya

Answer 6

bipashic fever
small joints polyarthralgia, Bilateral

Question 7

symmetric polyarthralgias of the hands and feet

Answer 7

chikungunya

Question 8

difference between CHKV and Dengue

Answer 8

CHKV has arthritis and NO hemoconcentration

Question 9

What are the diagnostic tests for chikungunya

Answer 9

Viral culture (<3 days), rtPCR (<8 days), IgM antibody (> days)

Question 10

Tx chikungunya

Answer 10

symptomatic therapy, NSAIDs, sometimes low dose steroids

Question 11

66yoM From Lima with fever, arthritis, 7 days fever HA muscle pain, then rash. DDx?

Answer 11

Mayaro v. Dengue v. Chik ; generally, arthritogenic alpha viruses (mayaro in this case)

Question 12

23year old female from lima with 4 days of fever, chills, malaise, myagias, arthralgias, HA after travel to iquitos. No rash, bleeding, jaundice, abdominal pain, cough, SOB, GI Sx. Then non-purulent conjunctivitis

Answer 12

Zika Virus (flavivirus)

Question 13

Zika virus transmission

Answer 13

mosquitos, Virus RNA in semen (sexual transmission), some transplacental and perinatal infection, blood transfusion

Question 14

symptoms of zika

Answer 14

rash, fever, arthralgias, conjunctivitis, myalgias, headache

Question 15

similarities and differences between zika, chkv, dengue

Answer 15

Question 16

congenital zika syndrome

Answer 16

calcifications, atrophy, microcephaly, fontanelle closure, joint problems, strabismus

Question 17

hyporeflexia, leg weakness, leg paresthesia, arm weakness, dysphagia

Answer 17

guillain barre in zika

Question 18

how to diagnose zika

Answer 18

real time PCR in serum/urine <14 days; serology IgM>14th day

Question 19

If a pregnant asymptomatic woman, but exposed to zika, when do you test

Answer 19

NAT testing for Zika 3 times during pregnancy

Question 20

Lab interpretation: ZIK , Deng neg, Chik neg

Answer 20

likely zika

Question 21

If zika, dengue, and chik are all positive

Answer 21

its a flavivirus infection + Chik co infection

Question 22

Difference between CHIKungunya and ZIKA

Answer 22

Chikungunya: symptomatic fever, athralgia, rash arhtiritis (can be chronic)
ZIKA: Mild illness, low fever, pruritic rash, conjunctivitis, could be associated with GBS

Question 23

What are the flaviviruses that cause hemorrhagic fever and encephalitis?

Answer 23

WNV
JE
St. Louis encephaltiis
Tick born encephalitis
Murray Valley enceph

Question 24

Japanese encephalitis is endemic where

Answer 24

Asia (Japan, taiwan, korea, china; malaysia, indonesia, philippines)

Question 25

Vector of JEV

Answer 25

Culex species

Question 26

Hosts of JE Virus

Answer 26

Bird: viremic, reservoir and amplyfying host
Pig: Abortion, death; major amplifying host
Human: Encephalitis, non-transmitting/dead end host

Question 27

Meningitis, encephalitis, acute flaccid paralysis

Answer 27

Japanese encephalitis

Question 28

seizures, CT shows lesions in basal ganglia, acute flaccid paralysis , LP shows normal to increase protein, pleocytosis, mainly lymphs, normal glucose

Answer 28

Japanese encephalitis

Question 29

Answer 29

T2 MRI with bilateral thalamic involvement-JEV Encephalitis

Question 30

How do you diagnose JEV

Answer 30

PCR can be positive; CSF IgM

Question 31

Vaccine for JE

Answer 31

inactivated vaccine, 2 doses 28 days apart; if exposed >1 month to rural areas during the rainy season