Virology Quiz 2 Arboviruses And Rubella Virus

Front 1

for what does arbovirus stand?

Back 1

arthropod-borne virus

Front 2

are arboviruses normally enveloped or not?

Back 2

yes

Front 3

typically, what type of nucleocapsid do arboviruses possess? What type of genome?

Back 3

icosahedral; +ssRNA

Front 4

are all togaviruses and flaviviruses arboviruses?

Back 4

no, some are not such as rubella and Hepatitis C

Front 5

what is the intrinsic incubation period of the arbovirus? How long is it?

Back 5

the human incubation period; usually a week or longer

Front 6

what is the extrinsic incubation period of the arbovirus? How long is it?

Back 6

the mosquito incubation period; 14 days

Front 7

is the mosquito ever harmed by the arbovirus?

Back 7

no

Front 8

can an arthropod transmit an arbovirus to its progeny? Via which route?

Back 8

often, but not always; transovarian

Front 9

where are most arboviruses located?

Back 9

in the tropics

Front 10

what is the only serious arbovirus disease in the USA? Which 5 viruses are responsible?

Back 10

encephalitis; Eastern equine encephalitis, Western equine encephalitis, St. Louis encephalitis, West Nile virus, and the California group of encephalitis viruses

Front 11

from what does the iniitial viremia in arboviral encephalitis stem?

Back 11

multiplication in vascular endothelium

Front 12

what is the disease progression of arborviral encephalitis? What is the treatment?

Back 12

brief febrile malaise followed by encephalitis with paralysis, coma, and death; no specific treatment available.

Front 13

which of the encephalitic arboviruses causes the most severe arboviral encephalitis?

Back 13

Eastern equine encephalitis

Front 14

does Eastern equine encephalitis affect adults or children more? In addition to humans, which animal is also targeted by the virus?

Back 14

children; horses

Front 15

which species are dead-end hosts for Eastern and Western equine encephalitis viruses? In addition to mosquitos, which animal is crucial for the propogation of the virus?

Back 15

horses and humans; wild birds

Front 16

what are 2 good hints of impending Eastern equine encephaitis epidemic?

Back 16

excessive rainfall and abnormally high mosquito populations

Front 17

what are the 2 standard control measures against Eastern equine encephalitis?

Back 17

reduction of mosquito population and avoidance of mosquitoes during epidemic

Front 18

St. Louis encephalitis virus and West Nile virus are both members of which virus family? Are they antigenically similar?

Back 18

flavivirus; yes

Front 19

in which population are SLE and WN viral infections mostly fatal?

Back 19

elderly

Front 20

why are humans considered dead-end hosts for SLE and WN viral infections?

Back 20

they rarely have viremia high enough to infect mosquitos

Front 21

how are SLE and WN viral epidemics maintained?

Back 21

via bird->mosquito->bird cycles

Front 22

to which region of the world is SLE indigenous? WN virus?

Back 22

North America; North Africa and Middle East

Front 23

of Eastern encephalitis, Western encephalitis, WN virus, SLE, and LaCrosse virus, which is the most fatal?

Back 23

Eastern equine encephalitis

Front 24

what kind of birds are responsible for maintaining an epidemic of Eastern and Western equine encephalitis? SLE and WN virus?

Back 24

wild birds; domestic and wild birds

Front 25

Eastern and Western equine encephalitis are both members of which viral family?

Back 25

togavirus

Front 26

are arboviral epidemics in the temperate regions of longer or shorter duration than those in the tropics?

Back 26

shorter

Front 27

what are 2 diseases, other than encephalitis, that are attributed to arboviral infections?

Back 27

yellow fever and dengue fever

Front 28

is dengue fever usually life-threatening? What are the symptoms?

Back 28

no; fever, severe headache, muscle and joint pain, rash

Front 29

what is the incubation period for dengue fever? Where is it most commonly found?

Back 29

1 week; in the tropics and subtropics, especially SE Asia and Caribbean islands

Front 30

how many different antigenic types of dengue virus exist? Do they cross-react?

Back 30

4; yes

Front 31

are humans dead-end hosts for dengue viral infections?

Back 31

no

Front 32

what symptoms characterize dengue hemorrhagic fever? Is this seen more in the native or visiting population?

Back 32

hemorrhage, vomiting blood, and shock; native

Front 33

what is the underlying mechanism behind hemmorhage in dengue hemorrhagic viral infections?

Back 33

macrophage infection causes increase in lymphokines and cytokines which causes hemorrhage

Front 34

how long is the incubation period for yellow fever?

Back 34

5 days

Front 35

where does yellow fever virus first multiply in the host? Where does it spread from there?

Back 35

vascular endothelium; liver and other organs

Front 36

what symptoms characterize yellow fever?

Back 36

fever, nausea, jaundice

Front 37

in addition to the liver, where does yellow fever viral multiplication occur?

Back 37

in spleen and kidney

Front 38

are there subclinical infections of yellow fever? Is the mortality for yellow fever high?

Back 38

yes; high

Front 39

where is yellow fever found now?

Back 39

in rural tropical Africa and South America

Front 40

which species of mosquito is the arthropod host for dengue and yellow fever?

Back 40

Aedes Aegypti

Front 41

other than mosquitoes, which animal is responsible for the spread of jungle yellow fever?

Back 41

monkey

Front 42

Is there a vaccine available for yellow fever? What type of vaccine is it?

Back 42

yes, D17; live-attenuated

Front 43

what is the risk of an unvaccinated person entering during a yellow fever incubation period? Where is this a problem right now?

Back 43

the virus may spread to the mosquitoes then to the susceptible population; in the southeastern US

Front 44

what are vertical infections? Horizontal infections?

Back 44

infections transmitted from mother to progeny; all other infections

Front 45

what are the 2 pathways that lead to vertical infections?

Back 45

perinatal and transplacental

Front 46

which viruses are perinatally acquired?

Back 46

HBV, HIV, herpes simplex type 2

Front 47

what are the implications of transplacental infections? What are 4 examples of viruses transmitted in this manner?

Back 47

they can result in congenital abnormalities due to interference with normal development; parvovirus B19, rubella, cytomegalovirus, and lymphocytic choriomeningitis

Front 48

are embryonic cells and embryos good hosts for viral growth?

Back 48

yes, but this is prevented by the placenta

Front 49

how do transplacental infections cross the placenta?

Back 49

by replicating in placental tissue

Front 50

what are fetal defense mechanisms against viral infections?

Back 50

maternal IgG, fetal Ab after 4th month, inteferon, and cell-mediated immunity

Front 51

are parvovirus virions enveloped? What is their capsid symmetry? Their genome?

Back 51

no; icosahedral; linear ssDNA

Front 52

what is the route of infection of parvovirus B19?

Back 52

inhalation of a respiratory aerosol from the resp tract of an infected person

Front 53

what are the symptoms of a parvoviral infection?

Back 53

atymptomatic or fever, malaise, rash called erythema infectiosum

Front 54

what is the likely cause of the rash which presents in parvoviral infections?

Back 54

deposition of immune complexes in capillaries

Front 55

for which cell type does parvovirus B19 have a tropism? What impact does the initial infection have on the host?

Back 55

erythroid precursors; inhibition of RBC production for about a week

Front 56

how well do normal people tolerate the cessation of RBC production in parvoviral infections?

Back 56

just fine

Front 57

what occurs during the beginning of a parvoviral infection in hosts with a pre-existing deficit in red blood cell production or a pre-existing abnormally high rate of red cell destruction?

Back 57

they will have a transient aplastic crisis which can be fatal without transfusions

Front 58

what chronic condition can result in patients that are unable to fight the parvoviral infection? What treatment is used for these patients?

Back 58

prolonged anemia; immunization with pooled IgG

Front 59

what is the most common symptom in primary parvoviral infection?

Back 59

acute arthritis

Front 60

what symptom is unique to first- and second-trimester parvoviral infections in developing fetuses?

Back 60

hyrops fetalis

Front 61

to what family of viruses does rubella belong? It is transmitted via arthropod infection?

Back 61

togavirus; no

Front 62

how is rubella virus transmitted?

Back 62

by respiratory aerosols from the resp tract of an infected person. Local multiplication in the resp epithelium is followed by viremia

Front 63

which is more contagious, rubella or measles virus?

Back 63

measles virus

Front 64

how long is the incubation period for rubella virus? Is rubella ever subclinical?

Back 64

18 days; yes

Front 65

how long does the rubella rash last? What other symptoms are present at this time?

Back 65

3 days; fever and lymphadenopathy

Front 66

when, in relation to the rash, is rubella virus excreted from the respiratory tract?

Back 66

one week before and after the rash

Front 67

what symptom of severe rubella viral infections is seen in adults?

Back 67

transient arthritis

Front 68

what congenital anomalies can result from a transplacental rubella infection?

Back 68

cataracts, heart defects (patent ductus arteriosus), deafness, retardation

Front 69

does deafness associated with congenital rubella worsen during life?

Back 69

yes, it may not be obvious at birth but becomes progressively worse in early years of life

Front 70

what is the main purpose of the live rubella vaccine?

Back 70

to prevent congenital rubella

Front 71

in addition to children, who else should receive the rubella vaccine?

Back 71

seronegative women of child-bearing age

Front 72

is rubella still a public health problem in developing countries?

Back 72

yes