Mosquito Surveillance and Polymerase Chain Reaction Detection of West Nile Virus, New York State

Abstract

West Nile (WN) virus was detected in the metropolitan New York City (NYC) area during the summer and fall of 1999. Sixty-two human cases, 7 fatal, were documented. The New York State Department of Health initiated a departmental effort to implement a statewide mosquito and virus surveillance system. During the 2000 arbovirus surveillance season, we collected 317,676 mosquitoes, submitted 9,952 pools for virus testing, and detected 363 WN virus-positive pools by polymerase chain reaction (PCR). Eight species of mosquitoes were found infected. Our mosquito surveillance system complemented other surveillance systems in the state to identify relative risk for human exposure to WN virus. PCR WN virus-positive mosquitoes were detected in NYC and six counties in the lower Hudson River Valley and metropolitan NYC area. Collective surveillance activities suggest that WN virus can disperse throughout the state and may impact local health jurisdictions in the state in future years.

Dead Crow Densities and Human Cases of West Nile Virus, New York State, 2000

“…This pattern was supported by data from Connecticut showing moderate dead crow densities in a county that had viral activity in both 1999 and 2000 and one WN virus-positive person with a mild illness in 2000 (8). Similarly, Staten Island had a higher proportion of birds that tested positive and higher mosquito infection rates (9,10). These and other analyses of WN virus in the northeastern United States in 2000 (3,(8)(9)(10) indicate that dead bird and mosquito surveillance can be useful for monitoring viral activity and the potential for human cases in this geographic area.…”

“…Similarly, Staten Island had a higher proportion of birds that tested positive and higher mosquito infection rates (9,10). These and other analyses of WN virus in the northeastern United States in 2000 (3,(8)(9)(10) indicate that dead bird and mosquito surveillance can be useful for monitoring viral activity and the potential for human cases in this geographic area. Tracking dead crow density avoids delays inherent in specimen collection and testing and thus may be more helpful on a weekly basis to permit rapid recognition of trends in viral activity and the potential for occasional human cases or an outbreak.…”

Virus Detection Protocols for West Nile Virus in Vertebrate and Mosquito Specimens

“…no. 2236335-2), each containing one 4.5-mm-diameter zincplated steel BB (Daisy brand), and shipped to the Arbovirus Laboratories on dry ice (15). For evaluation of RNA purification with the use of a robotic workstation, Culex pipiens mosquitoes were inoculated with 10 PFU of WNV, incubated for 4 days at 27°C, and subsequently frozen at Ϫ80°C.…”

Development of Multiplex PCR-Ligase Detection Reaction Assay for Detection of West Nile Virus

“…It made its first appearance in the western hemisphere in 1999, when 62 cases of WNV encephalitis and seven fatalities were reported in New York City (10,22,26). A surveillance program of mosquito pools was initiated by the New York City Department of Health and Mental Hygiene in 2000 (36,37), and blood donor screening was introduced in the United States in June 2003 after the report of WNV transmission to 23 individuals from 16 viremic donors in the preceding year (8,33). Since its introduction into the United States, the virus has rapidly spread and it is now endemic in 41 states and the District of Columbia (11).…”