Longitudinal Studies of West Nile Virus Infection in Avians, Yucatán State, México

Abstract

Following the introduction of West Nile virus (WNV) into North America in 1999, surveillance for evidence of infection with this virus in migratory and resident birds was established in Yucatán State, México in March 2000. Overall, 8611 birds representing 182 species and 14 orders were captured and assayed for antibodies to WNV. Of these, 5066 (59%) birds were residents and 3545 (41%) birds were migrants. Twenty-one (0.24%) birds exhibited evidence of flavivirus infection. Of these, 8 birds had antibodies to WNV by epitope-blocking enzyme-linked immunosorbent assay. Five (0.06%) birds (gray catbird, brown-crested flycatcher, rose-breasted grosbeak, blue bunting and indigo bunting) were confirmed to have WNV infections by plaque reduction neutralization test. The WNV-infected birds were sampled in December 2002 and January 2003. The brown-crested flycatcher and blue bunting presumably were resident birds; the other WNV seropositive birds were migrants. These data provide evidence of WNV transmission among birds in the Yucatán Peninsula.

Prevalencia de infección por el virus del Nilo Occidental en dos zoológicos del estado de Tabasco

“…[21][22][23][24][25][26][27] por estudios llevados a cabo principalmente en aves, equinos y mosquitos. [40][41][42] Hasta la fecha se han aislado y caracterizado genéticamente una variedad de virus de seres humanos, animales y mosquitos. [40][41][42][43][44]54,55 Los zoológicos incluidos en este estudio se encuentran ubicados en sitios donde la densidad vectorial y el considerables, lo cual representa un riesgo de infección por VNO en diversas especies.…”

“…[40][41][42] 44 Los zoológicos ubicados en zonas endémicas o de riesgo son sitios adecuados para el monitoreo del -puso un sistema de vigilancia epidemiológica donde se obtuvieron datos importantes sobre los principales mosquitos vectores del virus y las especies animales susceptibles a la infección, lo cual permitió fortalecer las acciones de prevención y control. 45 El objetivo de este trabajo fue determinar la prevalencia de infección por VNO en animales, mosquitos y personal que labora en dos zoológicos del estado de 232 aves, y otras 29 de 335 mamíferos; ninguno de los animales manifestó enfermedad alguna en los tres meses previos a la toma de la muestra.…”

West Nile Virus Ecology in a Tropical Ecosystem in Guatemala

“…2,3 Culex mosquitoes and passerine birds appeared to be responsible for WNV amplification in Puerto Rico in 2007. 4,5 By 2007, serologic evidence for WNV circulation in free-ranging birds and/or horses was reported in numerous tropical locations around the rim of the Caribbean Basin, including Mexico, [6][7][8] Guatemala, 9,10 Costa Rica, 11 Colombia, 12 Venezuela, 13 Guadaloupe, 14 Puerto Rico, 15 Dominican Republic, 16,17 Haiti, 18 Jamaica, 19 and Cuba. 15 Ecological parameters of WNV transmission have yet to be clearly defined in tropical ecosystems typical of the Caribbean Basin countries.…”

“…1 Serosurveys of free-ranging birds in several countries have identified infections in numerous species of birds but with the exception of a recent report in Puerto Rico, 4 none of these studies were focused in time and place coincident with active transmission. 7,8,16,17,19 Similarly, several isolates were derived from various species of Culex mosquitoes in tropical America, but except for Puerto Rico, 5 insufficient data were available to incriminate them as WNV vectors. [20][21][22] To determine vectors and amplifying hosts, it is necessary to study WNV ecology within a transmission focus.…”

Evaluation of an Epitope-Blocking Enzyme-Linked Immunosorbent Assay for the Diagnosis of West Nile Virus Infections in Humans

“…Serological diagnosis of WNV infections is complicated by the high rates of both primary DENV infections and secondary DENV infections in inhabitants of Thailand and Yucatan, Mexico, with seroprevalence rates of Ͼ85% in Thailand (1) and 72% in the Yucatán in 1985 (12,28). WNV introduction into the Yucatán in 2002 was revealed by detection of antibodies in horses (29) and then later in migratory and resident birds (10) and in zoo animals (11). However, no WNV infections of humans have been diagnosed in the Yucatán.…”