18-ARBOVIRUSES Flashcards
(210 cards)
1
Q
Which viruses are transmitted by bloodsucking arthropods from one vertebrate host to another
A
Arboviruses
2
Q
Which diseases are major arbovirus diseases worldwide
A
Yellow fever + Dengue + Japanese B encephalitis + St Louis encephalitis + Western equine encephalitis + Eastern equine encephalitis + Tick-borne encephalitis + West Nile fever + Sandfly fever + La Crosse encephalitis
3
Q
How are rodent-borne viral diseases maintained in nature
A
Direct intraspecies or interspecies transmission from rodent to rodent
4
Q
Which are major rodent-borne viral diseases
A
Hantavirus infections + Lassa fever + South American hemorrhagic fevers + Colorado tick fever + Marburg + Ebola
5
Q
Where are arboviruses commonly found
A
Tropics
6
Q
Which arboviruses are not zoonotic
A
Urban yellow fever + Dengue
7
Q
What are the three clinical syndromes produced by arboviruses
A
Undifferentiated fever with or without rash + Encephalitis + Hemorrhagic fevers
8
Q
Which family includes alphaviruses and rubivirus
A
Togaviridae
9
Q
Which viruses are mosquito-borne alphaviruses causing encephalitis
A
Western equine encephalitis + Eastern equine encephalitis + Venezuelan equine encephalitis
10
Q
Which virus causes rubella
A
Rubivirus
11
Q
Which are the most severe arboviral encephalitides
A
Eastern equine encephalitis + Western equine encephalitis
12
Q
Which mosquito is involved in western equine encephalitis transmission
A
Culex tarsalis
13
Q
Where have outbreaks of western equine encephalitis occurred
A
Western United States + Canada
14
Q
Which virus is the most important cause of epidemic encephalitis in North America
A
St Louis encephalitis
15
Q
How many cases and deaths has St Louis encephalitis caused since 1933
A
10,000 cases + 1,000 deaths
16
Q
What is required before human infection with St Louis encephalitis
A
Presence of infected mosquitoes
17
Q
What factors affect exposure to St Louis encephalitis
A
Socioeconomic + Cultural factors + Air conditioning + Screens + Mosquito control
18
Q
Which virus is the leading cause of arboviral encephalitis in the United States
A
West Nile fever
19
Q
Which complex does West Nile fever belong to
A
Japanese B encephalitis antigenic complex
20
Q
Where did West Nile virus originate
A
Middle East
21
Q
Which receptor is a risk factor for symptomatic West Nile infections
A
Chemokine receptor CCR5
22
Q
Which modes of person-to-person transmission were documented for West Nile virus in 2002
A
Organ transplantation + Blood transfusion + In utero + Breastfeeding
23
Q
What are the clinical features of West Nile fever
A
Viremia + Acute mild febrile disease + Lymphadenopathy + Rash + Transitory meningeal involvement
24
Q
How many antigenic types of West Nile virus exist
A
One
25
What is the prevention for West Nile virus
Mosquito control + Protection against mosquito bites
26
Is there a human vaccine for West Nile virus
No
27
Which virus is the leading cause of viral encephalitis in Asia
Japanese B encephalitis
28
How many cases and deaths of Japanese B encephalitis occur annually in Asia
50,000 cases + 10,000 deaths
29
Which age groups are mostly affected by Japanese B encephalitis
Children + Elderly adults
30
What is the ratio of asymptomatic to symptomatic infections in Japanese B encephalitis
300 to 1
31
Is there a treatment for Japanese B encephalitis
No
32
Which vaccine is available for Japanese B encephalitis in the US
Inactivated Vero cell culture-derived vaccine
33
Which virus clinically resembles dengue fever and is characterized by high fever and severe joint pain
Chikungunya virus
34
Is there a vaccine for chikungunya virus
No
35
Which virus causes tick-borne encephalitis
Tick-borne encephalitis virus
36
Where do most cases of tick-borne encephalitis occur
Baltic states + Slovenia + Russia
37
Which ticks transmit tick-borne encephalitis
Ixodes persulcatus + Ixodes ricinus
38
Which subtypes of tick-borne encephalitis virus cause human disease
European + Far-Eastern + Siberian
39
Is there a specific treatment for tick-borne encephalitis
No
40
Which countries produce effective vaccines for tick-borne encephalitis
Austria + Germany + Russia
41
Which strains are tick-borne encephalitis vaccines based on
European + Far-Eastern
42
Which disease is an acute febrile mosquito-borne illness in the tropics and subtropics of Africa and South America
Yellow fever
43
Which organs are affected in severe yellow fever
Liver + Kidney + Spleen + Lymph nodes + Heart
44
What are the major complications of severe yellow fever
Hemorrhage + Circulatory collapse + Myocardial injury + Shock
45
What are the two major epidemiologic cycles of yellow fever transmission
Urban yellow fever + Jungle yellow fever
46
Which mosquito transmits urban yellow fever
Domestic Aedes mosquitoes
47
Where does urban yellow fever transmission occur
West Africa
48
What is the reservoir in jungle yellow fever
Monkeys
49
Where does jungle yellow fever occur
South America + Africa
50
Which vaccine is used for yellow fever prevention
17D strain of yellow fever virus
51
What is the 17D yellow fever vaccine derived from
Asibi strain
52
Which genus and family does Rift Valley fever virus belong to
Genus Phlebovirus + Family Bunyaviridae
53
Which genus and family does Colorado tick fever virus belong to
Genus Coltivirus + Family Reoviridae
54
Which genus and family does Marburg virus belong to
Genus Marburgvirus + Family Filoviridae
55
Which genus and family does Ebola virus belong to
Genus Ebolavirus + Family Filoviridae
56
Which genus and family does dengue virus belong to
Genus Flavivirus + Family Flaviviridae
57
Which genus and family does Japanese B encephalitis virus belong to
Genus Flavivirus + Family Flaviviridae
58
Which genus and family does St Louis encephalitis virus belong to
Genus Flavivirus + Family Flaviviridae
59
Which genus and family does West Nile fever virus belong to
Genus Flavivirus + Family Flaviviridae
60
Which genus and family does Chikungunya virus belong to
Genus Alphavirus + Family Togaviridae
61
Which genus and family does La Crosse encephalitis virus belong to
Genus Orthobunyavirus + Family Bunyaviridae
62
Which genus and family does Hantavirus pulmonary syndrome virus belong to
Genus Hantavirus + Family Bunyaviridae
63
Which genus and family does Crimean-Congo hemorrhagic fever virus belong to
Genus Nairovirus + Family Bunyaviridae
64
Which genus and family does African horse sickness virus belong to
Genus Orbivirus + Family Reoviridae
65
Which genus and family does Bluetongue virus belong to
Genus Orbivirus + Family Reoviridae
66
Which genus and family does Semliki Forest virus belong to
Genus Alphavirus + Family Togaviridae
67
Which genus and family does Sindbis virus belong to
Genus Alphavirus + Family Togaviridae
68
Which genus and family does Lassa fever virus belong to
Genus Arenavirus + Family Arenaviridae
69
Which genus and family does lymphocytic choriomeningitis virus belong to
Genus Arenavirus + Family Arenaviridae
70
Which virus causes dengue
Flavivirus
71
How is dengue transmitted
Mosquito-borne
72
What are the classic symptoms of dengue
Fever + Severe headache + Muscle and joint pain + Nausea and vomiting + Eye pain + Rash
73
What are the severe forms of dengue
Dengue hemorrhagic fever + Dengue shock syndrome
74
When does clinical disease begin after a mosquito bite
4 to 7 days (range 3 to 14 days)
75
How long does dengue fever typically last
2 to 7 days
76
What are the prodromal symptoms of dengue
Malaise + Chills + Headache
77
Where do pains develop in dengue
Back + Joints + Muscles + Eyeballs + Deep bone
78
What is the characteristic fever pattern in dengue
Saddleback fever (rise again 5 to 8 days after onset)
79
When does the rash usually appear in dengue
Third or fourth day
80
How long does the rash last in dengue
1 to 5 days
81
What is found on physical exam in dengue
Enlarged lymph nodes
82
Is classic dengue self-limited
Yes
83
Which individuals are at risk for severe dengue
Children with passively acquired or preexisting non-neutralizing heterologous dengue antibody
84
What is the key pathological feature of severe dengue
Increased vascular permeability with plasma leakage
85
Which cells are the major target in dengue
Monocytes
86
Is there antiviral drug therapy for dengue
No
87
How is dengue hemorrhagic fever treated
Fluid replacement therapy
88
Why is dengue vaccine development difficult
Must provide protection against all four serotypes
89
What are the control measures for dengue
Anti-mosquito measures + Elimination of breeding places + Use of insecticides + Screened windows and doors
90
Which family includes viruses causing mosquito-borne encephalitides and hemorrhagic fevers
Bunyaviridae
91
What inactivates bunyaviruses
Heat + Detergents + Formaldehyde + Low pH
92
Which bunyavirus is transmitted by rodents
Hantavirus pulmonary syndrome
93
Which virus complex comprises 14 antigenically related viruses in Orthobunyavirus genus
California encephalitis virus complex
94
Which virus is a significant human pathogen in the United States
La Crosse virus
95
Which age group is most affected by La Crosse virus
Children under 16 years
96
When do most cases of La Crosse virus occur
July to September
97
Which mosquito is the vector for La Crosse virus
Aedes triseriatus
98
Which animals are principal vertebrate hosts for La Crosse virus
Squirrels + Chipmunks + Rabbits
99
Which virus causes sandfly fever
Bunyavirus in the Phlebovirus genus
100
Where does sandfly fever occur
Mediterranean countries + Russia + Iran + Pakistan + India + Panama + Brazil + Trinidad
101
Which mosquito is the vector for sandfly fever
Phlebotomus papatasii
102
When is sandfly fever prevalent in the tropics
All year
103
How is Rift Valley fever transmitted
Contact with infected animal blood and body fluids + Mosquito bites
104
What are the complications of Rift Valley fever
Retinitis + Encephalitis + Hemorrhagic fever + Permanent loss of vision
105
What is the mortality rate of Rift Valley fever
1 percent
106
Which virus causes Rift Valley fever
Bunyavirus in the Phlebovirus genus
107
Which animals are primarily affected by Rift Valley fever
Domestic livestock
108
Which virus causes Colorado tick fever
Coltivirus in the Reoviridae family
109
How many antigenic types of Colorado tick fever virus exist
One
110
Which tick is the vector for Colorado tick fever
Dermacentor andersoni
111
What are the causative agents of rodent-borne hemorrhagic fevers
Bunyaviruses + Arenaviruses + Filoviruses
112
Which regions are associated with Asian hemorrhagic fevers
Asia
113
Which viruses are associated with Asian hemorrhagic fevers
Hantaan virus + Seoul virus
114
Which regions are associated with South American hemorrhagic fevers
South America
115
Which viruses are associated with South American hemorrhagic fevers
Junin virus + Machupo virus
116
Which region is associated with African hemorrhagic fever
Africa
117
Which virus is associated with African hemorrhagic fever
Lassa virus
118
Which genus and family do hantaviruses belong to
Hantavirus genus + Bunyaviridae family
119
Which diseases are caused by hantaviruses
Hemorrhagic fever with renal syndrome + Hantavirus pulmonary syndrome
120
How are hantaviruses transmitted among rodents
Horizontally
121
How are hantaviruses transmitted to humans
Inhaling aerosols of rodent excreta
122
What determines the geographic distribution of hantavirus-associated diseases
Geographic distribution of rodent reservoirs
123
What is hemorrhagic fever with renal syndrome
Acute viral infection causing interstitial nephritis
124
What are the etiologic agents of hemorrhagic fever with renal syndrome
Hantaan virus + Dobrava virus + Seoul virus + Puumala virus
125
Which regions does hemorrhagic fever with renal syndrome occur
Asia + Europe + Scandinavia
126
Which rodent is the vector for hemorrhagic fever with renal syndrome
Apodemus agrarius
127
How is hemorrhagic fever with renal syndrome treated
Supportive therapy
128
How is hemorrhagic fever with renal syndrome prevented
Rodent control + Protection from exposure to rodent droppings
129
Which hantavirus caused an outbreak of severe respiratory illness in the United States in 1993
Sin Nombre virus
130
Which rodent is the primary reservoir for Sin Nombre virus
Deer mouse
131
Which hantaviruses cause hantavirus pulmonary syndrome in the United States
New York virus + Black Creek Canal virus + Bayou virus
132
Which virus causes hantavirus pulmonary syndrome in South America
Andes virus
133
Where is Andes virus found
Argentina + Chile
134
Does hantavirus pulmonary syndrome have person-to-person transmission
Yes during outbreaks
135
Which virus causes hantavirus pulmonary syndrome in Panama
Choclo virus
136
What is the pathogenesis of hantavirus pulmonary syndrome
Functional impairment of vascular endothelium
137
How is hantavirus pulmonary syndrome treated
Maintenance of oxygenation + Support of hemodynamic function
138
Which antiviral drug is used in hantavirus pulmonary syndrome
Ribavirin
139
What are the preventive measures for hantavirus pulmonary syndrome
Rodent control + Avoidance of contact with rodents and droppings + Avoid inhaling aerosolized dried excreta
140
What are the characteristics of arenaviruses
Pleomorphic particles + Segmented RNA genome + Envelope with large club-shaped peplomers + 50–300 nm diameter
141
How many RNA molecules are in the arenavirus genome
Two
142
What is the genetic organization of arenaviruses
Ambisense
143
What are the two divisions of arenaviruses
Old World viruses + New World viruses
144
Which groups are New World arenaviruses divided into
Group A + Group B + Whitewater Arroyo virus
145
Which group contains human pathogenic viruses in New World arenaviruses
Group B
146
How are humans infected with arenaviruses
Contact with rodent excreta
147
What diseases can arenaviruses cause
Severe hemorrhagic fever + Fetal infections
148
How are arenaviruses transmitted in natural rodent hosts
Vertical and horizontal routes
149
Which fluids may be involved in arenavirus transmission in rodents
Milk + Saliva + Urine
150
Which virus was first recognized in Nigeria in 1969 among Americans stationed in the village of Lassa
Lassa virus
151
Which countries are endemic for Lassa virus
All western African countries between Senegal and Republic of Congo
152
What is the incubation period for Lassa fever
1 to 3 weeks
153
What is a common complication of Lassa fever
Deafness
154
Is deafness from Lassa fever usually permanent
Yes
155
Which rodent is the principal reservoir for Lassa virus
Mastomys natalensis
156
How is Lassa virus transmitted from rodents to humans
Direct contact + Ingestion or inhalation of contaminated materials + Contamination of broken skin or mucous membranes + Consumption of infected rodents
157
How is Lassa virus transmitted between humans
Contact with infected bodily fluids + Blood + Saliva + Urine + Semen
158
How long can Lassa virus be excreted in urine after onset of illness
3 to 9 weeks
159
How long can Lassa virus be excreted in semen after onset of illness
Up to 3 months
160
Which setting is human-to-human transmission most common
Healthcare settings
161
What is the drug of choice for Lassa fever
Ribavirin
162
Is there a vaccine for Lassa fever
No
163
Which experimental vaccine has shown protective immunity in animals
Vaccinia virus recombinant
164
Which virus causes lymphocytic choriomeningitis
Lymphocytic choriomeningitis virus
165
When was lymphocytic choriomeningitis virus discovered
1933
166
Where is lymphocytic choriomeningitis virus widespread
Europe + Americas
167
Which rodent is the natural vector for lymphocytic choriomeningitis virus
Mus musculus
168
Which other rodents can lymphocytic choriomeningitis virus infect
Hamsters
169
How is lymphocytic choriomeningitis virus transmitted to humans
Mouse droppings
170
Is there evidence of person-to-person transmission of lymphocytic choriomeningitis virus
No
171
What are the clinical manifestations of lymphocytic choriomeningitis in humans
Aseptic meningitis + Mild systemic influenza-like illness
172
What are the rare severe manifestations of lymphocytic choriomeningitis
Severe encephalomyelitis + Fatal systemic disease
173
What is the incubation period for lymphocytic choriomeningitis
1 to 2 weeks
174
How long does lymphocytic choriomeningitis illness last
1 to 3 weeks
175
Which complex do South American arenaviruses belong to
Tacaribe complex
176
Which rodents are reservoirs for South American arenaviruses
Cricetid rodents
177
Which viruses are serious human pathogens in South America
Junin virus + Machupo virus + Guanarito virus + Sabia virus
178
Which symptom is more common in South American hemorrhagic fevers than in Lassa fever
Bleeding
179
Which disease is a major public health problem in Argentina
Junin hemorrhagic fever
180
Which rodent is the reservoir for Junin hemorrhagic fever
Calomys musculinus
181
What is the treatment for Junin hemorrhagic fever
Convalescent human plasma
182
When is treatment for Junin hemorrhagic fever most effective
First week of illness
183
What is a late complication of treatment for Junin hemorrhagic fever
Self-limited neurologic syndrome 3 to 6 weeks later
184
What is the prevention for Junin hemorrhagic fever
Live-attenuated Junin virus vaccine
185
Which disease was first identified in Bolivia in 1962
Machupo hemorrhagic fever
186
Which rodent is the reservoir for Machupo hemorrhagic fever
Calomys callosus
187
Which virus causes Venezuelan hemorrhagic fever
Guanarito virus
188
When was Guanarito virus identified
1990
189
What was associated with the emergence of Guanarito virus
Clearance of forest land for small farm use
190
Which virus was isolated in 1990 from a fatal case in Brazil
Sabia virus
191
Do Guanarito and Sabia viruses cause clinical disease similar to Argentine hemorrhagic fever
Yes
192
Which viruses are filoviruses
Marburg virus + Ebola virus
193
What are the four subtypes of Ebola virus
Zaire + Sudan + Reston + Ivory Coast
194
What is the morphology of filoviruses
Pleomorphic particles + Long filamentous threads or odd-shaped forms
195
What are the unit-length sizes of filovirus particles
665 nm for Marburg + 805 nm for Ebola
196
What is the genome structure of filoviruses
Single-stranded nonsegmented negative-sense RNA 19 kb in size + Seven genes
197
What is the biosafety level required for filovirus research
Biosafety Level 4
198
How is filovirus infectivity destroyed
Heating at 60°C for 30 minutes + Ultraviolet and gamma-irradiation + Lipid solvents + Bleach + Phenolic disinfectants
199
What are the suspected natural hosts for filoviruses
Bats + Possibly rodents
200
Which cells are targets for Marburg and Ebola viruses
Macrophage system + Dendritic cells + Interstitial fibroblasts + Endothelial cells
201
What is the incubation period for Marburg virus disease
3 to 9 days
202
What is the incubation period for Ebola virus disease
2 to 21 days
203
Are Marburg and Ebola virus infections usually fatal
Yes
204
When was Marburg virus disease first recognized
1967
205
Where was Marburg virus disease first recognized
Germany + Yugoslavia
206
Which animals were associated with the first Marburg virus outbreak
African green monkeys
207
When was Ebola virus discovered
1976
208
Where did the first Ebola outbreaks occur
Sudan + Zaire (now Democratic Republic of the Congo)
209
What is the main goal of treatment for filovirus infections
Maintain renal function + Electrolyte balance + Combat hemorrhage and shock
210
Is there a vaccine or specific antiviral therapy for filovirus infections
No
