Viral Encephalitis. Dan Karlin, Jenny Richmond, Chiemi Suzuki BIO 4158: Microbiology and Bioterrorism Dr. Zubay April 20, 2004. Roadmap. Introduction History and epidemiology Molecular biology Weaponization Clinical manifestations Preparednes and continued surveillance. Introduction.
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Dan Karlin, Jenny Richmond, Chiemi Suzuki
BIO 4158: Microbiology and Bioterrorism
April 20, 2004
Flaviviridae: West Nile Virus
Togaviridae: Eastern and Western Equine Encephalitis
Bunyaviridae: La Crosse Virus
Japanese Encephalitis Virus
St. Louis encephalitis virus
West Nile Virus
Eastern Equine Encephalitis Virus
Western Equine Encephalitis Virus
Venezuelan Equine Encephalitis Virus
La Crosse Virus
Transmission Cycle is Key to Weaponization from a crow found in New York.
West Nile virus
Bird reservoir hosts
Source: Dr. Ilya Trakht
In August 2002, a 91 year old male from Northern Staten Island who presented initially with sudden onset of fever, left lower extremity weakness, inability to walk, and possibly some transient and mild AMS, was admitted to a Staten Island hospital.
He was not considered to have aseptic meningitis or encephalitis and WN virus infection was not considered at that time. After being discharged, he was evaluated by a neurologist for persistent left leg weakness and inability to walk.
In April 2003, the neurologist reported this case to the DOHMH as a possible polio case. Serological specimens were forwarded to the NYSDOH where they tested positive for WN virus.
Fever Uncommon Common
Headache Uncommon Common
AMS Steady deterioration May fluctuate
Focal Neurologic Signs Uncommon Common
Types of seizures Generalized Both
Blood: Leukocytosis Uncommon Common
CSF: Pleocytosis Uncommon Common
EEG: Diffuse slowing Common +Focal
MRI Often normal Focal Abn.
NEW YORK STATE DEPARTMENT OF HEALTH (NYSDOH)
Viral Encephalitis Letter of Agreement for
Physician Ordered Testing by Polymerase Chain Reaction (PCR)
NYSDOH's Wadsworth Center offers the following tests on CSF for viral encephalitis:
PCR testing for a panel of viruses, including: herpes simplex, varicella zoster, cytomegalovirus, Epstein-Barr virus, enteroviruses, St. Louis encephalitis (SLE), eastern equine encephalitis (EEE), California encephalitis (including LaCrosse and Jamestown Canyon viruses), Powassan and West Nile (WN) viruses, and
Enzyme-linked immunoassay (ELISA) for WN virus.
If there is insufficient quantity of CSF (less than 1.0 ml) to conduct both ELISA and PCR for WN virus, please consider the following in determining which test is most appropriate for your patient:
ELISA is more sensitive than PCR for WN viral testing and should be considered when there is stronger suspicion of WN virus than other viruses.
PCR is less sensitive for WN virus, but tests for a wide range of viruses. PCR should be considered if viruses other than WN virus are suspected.
Please note your testing priority below or on the viral encephalitis/meningitis case report form. If PCR testing is desired, the agreement below must be completed.
Viral Encephalitis PCR Panel West Nile Virus ELISA Antibody Testing
“To reduce WN transmission through blood components…. Blood donations will be screened for WN virus RNA… using nucleic acid amplification tests (NAT). In the event of a NAT-reactive donation, blood centers will remove and quarantine all blood components associated with the donation and notify the state or local health department. In addition, blood testing centers have added screening questions to identify and exclude persons with fever and headache in the week prior to donation.”
NYC DOHMH Statement:
“ We hope that spraying of adulticides will not be required this summer. However, if there is a threat of an outbreak of human illness and spraying is deemed necessary, targeted adult mosquito control measures (via ground or aerial spraying of pesticides) may be required.”
Confirmed or suspected cases of pesticide poisoning must be reported to the New York State Department of Health’s Pesticide Poisoning Registry at (800)-322-6850, and to the New York City Poison Control Center at (212)-764-7667.
“Since 2000, the NYC DOHMH has conducted comprehensive arthropod-borne disease surveillance and control. In 2003, efforts will again focus on mosquito control through reduction of breeding sites and application of larvicides. In addition, comprehensive mosquito, avian and human data collected during the 2000-2002 seasons have allowed NYC DOHMH to develop more sensitive surveillance criteria for determining the level of WN viral activity in birds and mosquitoes that may indicate a significant risk for a human outbreak. These indicators will be monitored citywide to identify areas at risk for human transmission.”
The Department of Health & Mental Hygiene is now accepting reports of standing water. However, we will not be able to visit and treat all reported nuisances. Therefore we are encouraging City residents and business owners to take immediate action to eliminate standing water on their property.
“Five pools of mosquitoes collected in New York City have tested positive for West Nile (WN) virus. These include a pool of Culex salinarius, a human biting mosquito, collected on July 15, in the Willowbrook Park area of Staten Island, a pool of Culex restuans, primarily a bird-biting mosquito, collected from Brookville Park, Queens on July 17, a pool of Culex pipiens, a mosquito that bites both birds and humans, collected from the Hunts Point area of the Bronx on July 18, a pool of Culex species collected from Jamaica Bay, Queens on July 16, and a pool of Culex salinarius collected from Greenwood Cemetery, Brooklyn on July 21. These positive pools are the first evidence of West Nile (WN) virus in New York City in 2003”
“The New York City Department of Health and Mental Hygiene (NYC DOHMH) is again requesting that during the peak adult mosquito season, from June 1 – October 31, 2003, all suspected cases of viral encephalitis (all ages) and viral meningitis (adults only) be reported immediately by telephone or facsimile and that appropriate laboratory specimens (cerebrospinal fluid and sera) be submitted promptly for testing for West Nile (WN) virus.”