Confirmed clinical and veterinary cases of West Nile virus (WNV) infection in Mexico remain restricted to northern Mexico, supporting a unidirectional transmission model from the US into Mexico. Full-length genomic sequencing of nine WNV isolates obtained from Culex spp. mosquito pools in El Paso, Texas (n=7) and Cuidad Juarez, Mexico (n=2) from 2005 to 2010 demonstrates the co-circulation of t...

Since the emergence of West Nile virus (WNV) in North America in 1999, there have been several reports of WNV activity in Central and South American countries. To detect WNV in Brazil, we performed a serological survey of horses from different regions of Brazil using recombinant peptides from domain III of WNV. Positive samples were validated with the neutralisation test. Our results showed tha...

Lying on my sleeping pad, I warily eye the mosquito perched above my head. I could reach up and squash it, but that would require extracting my arm from the warmth of my sleeping bag. So for now, it clings to the yellow nylon of my tent, unaware of its reprieve. Although I may triumph over this particular mosquito, I am all too aware of being vastly outnumbered outside my tent. Until recently, ...

Despite a cold temperate climate and low human population density, the Northern Great Plains has become a persistent hot spot for human West Nile virus (WNV) disease in North America. Understanding the spatial and temporal patterns of WNV can provide insights into the epidemiological and ecological factors that influence disease emergence and persistence. We analyzed the 1,962 cases of human WN...

To ascertain the presence of West Nile virus (WNV), we sampled mosquitoes in 2006 in locations in southern Spain where humans had been infected. WNV genomic RNA was detected in 1 pool from unfed female Culex pipiens mosquitoes. Phylogenetic analysis demonstrated that this sequence cannot be assigned to previously described lineages of WNV.

INTRODUCTION The objective of this study was to determine the prevalence of West Nile Virus infection in the southern provinces of Morocco. METHODOLOGY A total of 250 sera, collected during 2012 in the province of Dakhla, were analyzed by microneutralisation assay. RESULTS WNV-neutralizing antibodies were detected in 13 samples (5.2%). The participants with WNV-specific antibodies were sign...

BACKGROUND The incidence of West Nile virus (WNv) has remained high in the northern Great Plains compared to the rest of the United States. However, the reasons for the sustained high risk of WNv transmission in this region have not been determined. To assess the environmental drivers of WNv in the northern Great Plains, we analyzed the county-level spatial pattern of human cases during the 200...

Mosquitoes and birds were sampled for West Nile virus (WNV) in suburban Chicago, USA, in a "hot spot" of arboviral transmission. Viral genetic diversity within this area was similar to that within Illinois and the United States. Diversity was higher among viruses from mosquitoes than from birds, higher among viruses from birds in urban "green spaces" than from birds in residential areas, but lo...

To assess environmental and horse-level risk factors associated with West Nile Virus (WNV) circulation in Camargue, Southern France, a serosurvey was conducted on non-vaccinated horses (n = 1159 from 134 stables) in 2007 and 2008. Fifteen Landsat images were examined to quantify areas with open water and flooded vegetation around sampled horses. Mean percentages of areas of open water and flood...

1886 Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 10, No. 10, October 2004 study conducted on French blood donors from September to November 2000 showed low titers of WNV neutralizing antibodies in two donors originating from the Département du Var (6). However, to date, no clinical human cases have been reported in this area. WNV must be considered as a causative agent of meningitis, ...