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United States Department of Agriculture

Agricultural Research Service

Research Project: HIGHER DIPTERA PESTS OF LIVESTOCK AND POULTRY: SCREWWORM FLIES

Location: Screwworm Research

Title: Epidemiological modeling and risk analysis of Venezuelan Equine Encephalitis in the human population of Coastal Chiapas, Mexico in 2007-2009

Authors
item Ramierez-Aguilar, Francisco -
item Martinez-Alfaro, Carlos -
item Pimentel-Fernandez, Neftaly -
item Navarro-Lopez, Roberto -
item Phillips, Pamela -
item Weaver, Scott -
item Estrada-Franco, Jose -

Submitted to: American Society of Tropical Medicine and Hygiene
Publication Type: Abstract Only
Publication Acceptance Date: May 23, 2011
Publication Date: N/A

Technical Abstract: Analysis of 101 febrile illness patients sero positive for Venezuelan equine encephalitis (VEEV) was carried out in a retrospective study along 18 municipalities and endemic VEEV pacific coastal regions of the State of Chiapas in southern Mexico. Geographic information systems (GIS), satellite imagery and a detailed questionnaire were used in the analysis. Using ESRI ArcGIS 10.1 software and spatial statistics tools we measured the geographic distribution of VEEV cases along coastal Chiapas. The distribution of VEE cases were principally located along the Pacific coastal plain with the mean center of positive cases to be in the municipality of Huixtla. The directional distribution of cases around the mean were dispersed in a pattern between the Pacific coastline and the coastal mountain range. Temporal and spatial dynamics showed clear separation between cases in the southern and northern regions during the dry season with a peak of positive cases for both regions during the wet season. The analysis was based on Euclidian distances identifying spatially significant clusters as hot spots. The spatial analysis was complemented with relative risk (OR) bivariate and multivariate statistical analytical models showing neck stiffness (OR=6.03; 1.2318-29.5801, p=0.027) multivariate; (OR=13.87, IC 3.1861-60.4217, p=0.000), bivariate, muscle weakness (OR=10.12; IC 2.1633-47.4002, p=0.003) multivariate; (OR=23.05, IC5.3134-100.0692, p=0.000) bivariate, taste dysfunction (OR=3.54; IC 1.1380-11.0234, p=0.029) multivariate; (OR=6.40; IC 2.3449-17.5045, p=0.000) bivariate, and photophobia (OR=16.98, IC 2.2321-129.2713, p=0.006) bivariate and conjunctivitis (OR=3.25, IC 1.3273-7.9948, p=0.010) bivariate, as the most important clinical manifestations associated with VEEV for individuals of coastal Chiapas. Overall, our results indicate a coastal band of endemic VEE extending from the Guatemalan border through the State of Chiapas to the adjacent State of Oaxaca.

Last Modified: 9/10/2014
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