title: Sentinel site-enhanced near-real time surveillance documenting West Nile virus circulation in two Culex mosquito species indicating different transmission characteristics, Djibouti City, Djibouti.
abstract: The Horn of Africa represents a region formerly known to be highly susceptible to mosquito-borne infectious diseases. In order to investigate whether autochthonous WNV transmission occurs in the Djibouti City area, in how far, and which of, the endemic Culex mosquito species are involved in WNV circulation activity,and whether sentinel site-enhanced near-real time surveillance (SSE-NRTS) may increase WNV detection sensitivity, mosquito vector monitoring was conducted from January 2010 to June 2012. Six monitoring locations, including two identified sentinel sites, considered most probable for potential anthroponotic and zoonotic virus circulation activity, have been continuously employed. Among the 20431 mosquitoes collected, 19069 (93.4%) were Cx. quinquefasciatus, and 1345 (6.6%) Cx. pipiens ssp. torridus. WNV lineage 2 circulation activity was detected between December 20th, 2010 and January 7th, 2011. Overall, 19 WNV RNA-positive mosquito pools were detected. Generally, urban environment-specific WNV-RNA circulation took place in Cx. pipiens ssp. torridus, whereas periurban and rural area-linked circulation was detected only in Cx. quinquefasciatus. Serological investigation data from 10 volunteers employed at the dislocated zoonotic WNV transmission sentinel site suggest that six persons (60%) had an acute, or recent, WNV infection. Results show that WNV should be considered endemic for Djibouti and sentinel site-enhanced near-real time surveillance is an elegant and highly effective epidemiological tool. In Djibouti, the endemicity level, public health impact and transmission modes of vector-borne diseases in concordance with locally optimized monitoring and control regimen deserve further investigation.
authors.affiliation: Department of Medical Entomology/Zoology, Central Institute of the Bundeswehr Medical Service, PO Box 7340, 56065 Koblenz, Germany. MichaelFaulde@bundeswehr.org
authors.forename: Michael K
authors.initials: MK
authors.lastname: Faulde
authors.forename: Michael
authors.initials: M
authors.lastname: Spiesberger
authors.forename: Babiker
authors.initials: B
authors.lastname: Abbas
mesh_terms: D000818:Animals; D003465:Culex / Q000821:virology*; D015730:Djibouti / Q000453:epidemiology; D019353:Endemic Diseases; D005260:Female; D006801:Humans; D007303:Insect Vectors / Q000821:virology*; D008297:Male; D012367:RNA, Viral / Q000302:isolation & purification; D018571:Sentinel Surveillance; D014901:West Nile Fever / Q000453:epidemiology / Q000635:transmission*; D014902:West Nile virus / Q000235:genetics / Q000302:isolation & purification*; D015047:Zoonoses / Q000635:transmission / Q000821:virology
chemical_list: D012367:RNA, Viral