Twenty years of surveillance for Eastern equine encephalitis virus in mosquitoes in New York State from 1993 to 2012

Abstract

BackgroundThe year 1971 was the first time in New York State (NYS) that Eastern equine encephalitis virus (EEEV) was identified in mosquitoes, in Culiseta melanura and Culiseta morsitans. At that time, state and county health departments began surveillance for EEEV in mosquitoes.MethodsFrom 1993 to 2012, county health departments continued voluntary participation with the state health department in mosquito and arbovirus surveillance. Adult female mosquitoes were trapped, identified, and pooled. Mosquito pools were tested for EEEV by Vero cell culture each of the twenty years. Beginning in 2000, mosquito extracts and cell culture supernatant were tested by reverse transcriptase-polymerase chain reaction (RT-PCR).ResultsDuring the years 1993 to 2012, EEEV was identified in: Culiseta melanura, Culiseta morsitans, Coquillettidia perturbans, Aedes canadensis (Ochlerotatus canadensis), Aedes vexans, Anopheles punctipennis, Anopheles quadrimaculatus, Psorophora ferox, Culex salinarius, and Culex pipiens-restuans group. EEEV was detected in 427 adult mosquito pools of 107,156 pools tested totaling 3.96 million mosquitoes. Detections of EEEV occurred in three geographical regions of NYS: Sullivan County, Suffolk County, and the contiguous counties of Madison, Oneida, Onondaga and Oswego. Detections of EEEV in mosquitoes occurred every year from 2003 to 2012, inclusive. EEEV was not detected in 1995, and 1998 to 2002, inclusive.ConclusionsThis was the first time in NYS that EEEV was detected in Cx. salinarius, Ps. ferox and An. punctipennis. The detection of EEEV in mosquitoes every year for 10 years was the longest time span since surveillance began in 1971. The calendar date of the earliest annual appearance of EEEV in mosquitoes did not change during surveillance spanning 42 years.

Spatial and temporal expansions of Eastern equine encephalitis virus and phylogenetic groups isolated from mosquitoes and mammalian cases in New York State from 2013 to 2019

“…In New York State, EEE disease emerged first in pheasants in 1952 [19]; next in horses in 1970 [20] with a total of 151 horse cases through 2012 [8,15,18,21]; then in humans in 1971 [22] with a total of six human cases through 2012 [23]. Previous surveillance for EEE virus in mosquitoes from 1971 to 2012 found virus in 11 mosquito species [14,24]. This present work describes aspects of this disease and virus in our subsequent surveillance.…”

“…Within New York State EEE virus was not detected in mosquitoes in any of the years from 1998 to 2002. Then, EEE virus was detected in mosquitoes every year from 2003 to 2012 [14], which included the period of time, 2005-2012, when EEE virus emerged in the nearby states of Maine, Vermont, and New Hampshire.…”

“…Culiseta melanura is the first species of mosquito in which EEE virus is detected each season in our geographic region of central New York State [18]. EEE virus has appeared in new species of mosquitoes [14].…”

Sensitivity and specificity of metatranscriptomics as an arbovirus surveillance tool

“…Arboviruses represent a significant burden to human and animal health and include pathogens such as dengue, yellow fever, Zika, chikungunya, bluetongue and equine encephalitis viruses, with dengue virus alone infecting an estimated 390 million people per year 5 . Surveillance programs act as an early warning system for increased transmission risk and enlist tools such as mosquito trapping, virus isolation in cell culture, and targeted molecular virus detection using quantitative PCR (qPCR) assays [6][7][8] . Metatranscriptomics is a nontargeted method that offers many advantages for arbovirus surveillance programs.…”

Cases of Eastern equine encephalitis in humans associated with Aedes canadensis, Coquillettidia perturbans and Culiseta melanura mosquitoes with the virus in New York State from 1971 to 2012 by analysis of aggregated published data

“…Occurrences of human cases [1,9,11,13,15] along with the presence of mosquito species having the virus [8,13,14,16] have had a notable intermittency. Various mosquito species have been suggested as the transmitters of the virus to humans, or causative vectors [8,[16][17][18][19][20][21][22][23].…”