Vectors and malaria transmission in deforested, rural communities in north-central Vietnam

• Published in: Malaria Journal
• Main Authors: Do Manh Cuong, Beebe Nigel W, Thi Van Van Nguyen, Le Quang Tao, Lein Chau, Van Nguyen Dung, Xuan Thanh, Le Ngoc Anh, Cooper Robert D
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMC 2010
• Subjects: Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Arctic; Khe
• Online Access: https://doi.org/10.1186/1475-2875-9-259; https://doaj.org/article/c7734f58799840a38518aa933a3b6ba1

Abstract Background Malaria is still prevalent in rural communities of central Vietnam even though, due to deforestation, the primary vector Anopheles dirus is uncommon. In these situations little is known about the secondary vectors which are responsible for maintaining transmission. Basic information on the identification of the species in these rural communities is required so that transmission parameters, such as ecology, behaviour and vectorial status can be assigned to the appropriate species. Methods In two rural villages - Khe Ngang and Hang Chuon - in Truong Xuan Commune, Quang Binh Province, north central Vietnam, a series of longitudinal entomological surveys were conducted during the wet and dry seasons from 2003 - 2007. In these surveys anopheline mosquitoes were collected in human landing catches, paired human and animal bait collections, and from larval surveys. Specimens belonging to species complexes were identified by PCR and sequence analysis, incrimination of vectors was by detection of circumsporozoite protein using an enzyme-linked immunosorbent assay. Results Over 80% of the anopheline fauna was made up of Anopheles sinensis , Anopheles aconitus , Anopheles harrisoni , Anopheles maculatus , Anopheles sawadwongporni , and Anopheles philippinensis . PCR and sequence analysis resolved identification issues in the Funestus Group, Maculatus Group, Hyrcanus Group and Dirus Complex. Most species were zoophilic and while all species could be collected biting humans significantly higher densities were attracted to cattle and buffalo. Anopheles dirus was the most anthropophilic species but was uncommon making up only 1.24% of all anophelines collected. Anopheles sinensis , An. aconitus , An. harrisoni , An. maculatus , An. sawadwongporni, Anopheles peditaeniatus and An. philippinensis were all found positive for circumsporozoite protein. Heterogeneity in oviposition site preference between species enabled vector densities to be high in both the wet and dry seasons allowing for year round ...