West Nile Virus - Department of Public Health

116 Pages·2004·4.28 MB·English

WEST NILE VIRUS
INFECTION 2004
WESTWARD MIGRATION
Laurene Mascola, MD, MPH, FAAP
Chief, Acute Communicable Disease Control Program
County of Los Angeles Department of Health Services
UCLA Grand Rounds
July 2, 2004
Contributor: Rachel Civen, MD, MPH and Carol Ann Glaser, DVM, et al.
DHS
D16:\WNV_UCLA July 2_2004.ppt No. 1 Acute Communicable Disease Control
OUTLINE
West Nile Virus Overview
(cid:102)
West Nile Virus Outbreaks and entry to
(cid:102)
U.S. 1999
Surveillance
(cid:102)
Epidemiology and Clinical Presentation
(cid:102)
Diagnosis
(cid:102)
New Modes of Transmission
(cid:102)
Prevention
(cid:102)
DHS
Acute Communicable Disease Control Unit
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ARTHROPOD-BORNE
ENCEPHALITIS (1)
Agents: Eastern equine, Western
(cid:102)
equine, St. Louis, La
Crosse, California, West
Nile viruses
Incubation: 2-15 days
(cid:102)
Reservoir: Unknown, probably wild
(cid:102)
birds
Transmission: Bite of infective mosquitoes
(cid:102)
DHS
Acute Communicable Disease Control Unit
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ARTHROPOD-BORNE
ENCEPHALITIS (2)
Presentation: Ranges from
(cid:102)
asymptomatic to aseptic
meningitis to encephalitis
Diagnosis: Serologic tests
(cid:102)
Treatment: Supportive
(cid:102)
Prevention: Mosquito avoidance,
(cid:102)
Mosquito abatement
DHS
Acute Communicable Disease Control Unit
D16:\WNV_UCLA July 2_2004.ppt No. 4
WEST NILE VIRUS
Single-stranded RNA enveloped virus
(cid:102)
of the familily Flaviviridae, genus
Flavivirus
Japanese encephalitis virus
(cid:102)
(cid:57)West Nile virus (WNV)
(cid:57)Saint Louis encephalitis virus
(cid:57)Japanese Equine encephalitis virus
(cid:57)Murray Valley virus complex
(cid:57)Kinjin virus
DHS
Acute Communicable Disease Control Unit
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BACKGROUND: WNV
INFECTIONS (1)
1937: First isolated in West Nile district
(cid:102)
of Uganda
1957: Israeli nursing home outbreak
(cid:102)
(cid:57)Associated with severe neurologic
disease and higher mortality rate
1990s: Frequency and severity of WNV
(cid:102)
outbreaks increased
DHS
Acute Communicable Disease Control Unit
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BACKGROUND: WNV
INFECTIONS (2)
Outbreaks in:
(cid:102)
(cid:57)1994 Algeria
(cid:57)1996 Romania: associated with severe
neurologic illness
(cid:57)1997 Czech Republic
(cid:57)1998 Italy
(cid:57)1999 Russia: associated with severe
neurologic illness
(cid:57)1999 USA: entry into US/NY outbreak
DHS
Acute Communicable Disease Control Unit
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WEST NILE FEVER: BACKGROUND
AND EPIDEMIOLOGY (1)
Worldwide distribution
(cid:102)
Enzootic many parts of the world:
(cid:102)
Africa, Middle East, West Asia,
Australia
Caused primarily outbreaks of
(cid:102)
febrile illnesses: soldiers,
children, and healthy adults
DHS
Acute Communicable Disease Control Unit
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WEST NILE FEVER: BACKGROUND
AND EPIDEMIOLOGY (2)
Commonly found in humans and birds
(cid:102)
and other vertebrates
Basic transmission cycle involves
(cid:102)
mosquitoes feeding on birds infected
with the West Nile Virus
Infected mosquitoes then transmit
(cid:102)
West Nile Virus to humans and
animals when taking a blood meal
DHS
Acute Communicable Disease Control Unit
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WEST NILE VIRUS (WNV)
TRANSMISSION CYCLE
Mosquito Vector
Incidental Infections
West
Nile
Incidental Infections
Virus
Bird Reservoir
Hosts
DHS
Acute Communicable Disease Control Unit
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