Yard Flooding by Irrigation Canals Increased the Risk of West Nile Disease in El Paso, Texas

Abstract

Purpose To investigate the effects of use of water from irrigation canals to flood residential yards on the risk of West Nile disease in El Paso, Texas. Methods West Nile disease confirmed cases in 2009–2010 were compared with a random sample of 50 residents of the county according to access to and use of water from irrigation canals by subjects or their neighbors, as well as geo-referenced closest distance between their home address and the nearest irrigation canal. A windshield survey of 600 meters around the study subjects’ home address recorded the presence of irrigation canals. The distance from the residence of 182 confirmed cases of West Nile disease reported in 2003–2010 to canals was compared to that of the centroids of 182 blocks selected at random. Results Cases were more likely than controls to report their neighbors flooded their yards with water from canals. Irrigation canals were more often observed in neighborhoods of cases than of controls. Using the set of addresses of 182 confirmed cases and 182 hypothetic controls the authors found a statistically significant inverse relation with risk of West Nile disease. Conclusions Flooding of yards with water from canals increased the risk of West Nile disease.

Serosurvey for dengue virus infection among pregnant women in the West Nile virus enzootic community of El Paso Texas

“…Although 271 human cases of WN were reported annually between 2003 and 2016 in El Paso Texas, serosurveys have not been conducted to determine estimates of WNV IgG antibody as evidence of past infections in the population [ 19 , 78 ]. Our serosurvey provided further evidence of WNV human infection in the El Paso community, but was focused on rates among child-bearing age females.…”

“…The first WN human cases were reported during 2003 in El Paso, Texas, where Culex quinquefasciatus and Culex tarsalis are the primary vectors [16,18]. Estimates based on passive surveillance in El Paso indicated that 271 cases of WN occurred between 2003 and 2016, with cases occurring during late June to early November, and peaking in August during each year [17,19] Although DENV have not been reported to be associated with human infections and/or disease in the El Paso community, such cases and/or infections may not have been detected because of the reliance on passive surveillance to detect symptomatic cases. As an example, the use of passive surveillance during a 1980 dengue outbreak in Brownsville, TX failed to detect any dengue cases in El Paso, but 63 cases were detected by active surveillance.7 Another possibility for not detecting human cases is because DENV, like most arboviruses more commonly cause asymptomatic infections or infections that cause a mild influenza-like illness [20].…”

“…The first WN human cases were reported during 2003 in El Paso, Texas, where Culex quinquefasciatus and Culex tarsalis are the primary vectors [ 16 , 18 ]. Estimates based on passive surveillance in El Paso indicated that 271 cases of WN occurred between 2003 and 2016, with cases occurring during late June to early November, and peaking in August during each year [ 17 , 19 ]…”

Risk factors for West Nile virus infection and disease in populations and individuals

“…Similarly, in El Paso, Texas, where Cx. tarsalis is the primary vector, WNV case-patients were close to yards that were flooded regularly by irrigation canals (35). In northern Colorado, where Cx.…”

Detection and Characterization of Enteric Viruses in Flood Water from the 2011 Thai Flood

“…The pattern of prevalence of waterborne diseases such as typhoid fever, cholera, leptospirosis, diarrheal diseases, and hepatitis appears to have changed after the flood (2)(3)(4). The prevalence of not only waterborne diseases but also vectorborne diseases such as malaria, West Nile fever, and dengue fever has increased after the flood (5,6).…”