Diversity in breeding sites and distribution of Anopheles mosquitoes in selected urban areas of southern Ghana

Abstract

Background Anopheles vectors of malaria are supposedly less common in urban areas as a result of pollution, but there is increasing evidence of their adaptation to organically polluted water bodies. This study characterized the breeding habitats of Anopheles mosquitoes in the two major urban areas in southern Ghana; Accra (AMA) and Sekondi-Takoradi (STMA) Metropolitan Areas, during dry and wet seasons.Methods Anopheles mosquito larvae were sampled using standard dipping methods to determine larval densities. The origin, nature and stability of 21 randomly selected sites were observed and recorded. Mosquito larvae were reared to adults and Anopheles species identified by both morphological and molecular means.ResultsSixty-six percent of Anopheles habitats were permanent and 34% temporal, and 74.5% man-made while 25.5% were natural. Puddles and urban farm sites accounted for over 51% of all Anopheles mosquitoes sampled. The mean larval densities among the habitat types was highest of 13.7/dip for puddles and lowest of 2.3/dip for stream/river, and the variation between densities were significant (P = 0.002). The mean larval densities were significantly higher in the wet season than in the dry season for the two study areas combined (P = 0.0191) and AMA (P = 0.0228). Over 99% of the 5,802 morphologically identified Anopheles species were An. gambiae (s.l.) of which more than 99% of the studied 898 were An. coluzzii (62%) and An. gambiae (s.s.) (34%). Urban farms, puddles, swamps and ditches/ dugouts accounted for approximately 70% of all An. coluzzii identified. Conversely, drains, construction sites, streams/rivers and “others” contributed 80% of all An. gambiae (s.s.) sampled. The wet season had significantly higher proportion of Anopheles larvae compared to the dry season (Z = 8.3683, P < 0.0001). Also, the proportion of Anopheles mosquitoes produced by permanent breeding sites was 61.3% and that of temporary sites was 38.7%.ConclusionTaken together, the data suggest that man-made and/ or permanent habitats were the main contributors to Anopheles larval populations in the cities and that regulation of the anthropogenic processes that lead to development of breeding places and proper environmental management can drastically reduce mosquito breeding sites in urban areas of Ghana.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1941-3) contains supplementary material, which is available to authorized users.

Artificial Aquatic Ecosystems

“…Many artificial waterbodies support species-poor [60] or otherwise undesirable communities or organisms, including disease vectors [58,61,62], and can spread pest species to natural habitats [63,64]. Some have also contributed to, accelerated, or facilitated flow of excess nutrients and other pollutants [65,66], activation of toxicants [58], interrupted desirable species' movement and dispersal [67], increased greenhouse gas emissions [27,68], yielded bad smells [69], and even concealed crime [70].…”

Perbedaan Dataran Tinggi dan Dataran Rendah terhadap Keberagaman Spesies Anopheles spp. di Provinsi Nusa Tenggara Timur

“…3 Nyamuk Anopheles dapat hidup di kondisi lingkungan yang spesifik seperti di daerah pegunungan, hutan, rawa-rawa, pantai dan persawahan. 4 Populasi nyamuk Anopheles dipengaruhi oleh faktor predator, parasit, suhu, curah hujan dan iklim. 5 Tiap spesies Anopheles memiliki ciri khas ekosistem, spesies An.…”

Decision Making within the Built Environment as a Strategy for Mitigating the Risk of Malaria and Other Vector-Borne Diseases

“…(3) Detailed Design: Certain types of material on housing features, such as mud walls, thatched roofs, and earth, sand, dung, and stone flooring, increase vector attraction into the site [61]; (4) Construction: Excavation work results in opportunities for several pools of stagnant water to form-such pools are ideal breeding grounds for mosquitoes; (5) Facilities Management: Drains and ditches are common habitats for mosquitoes to breed [62];…”

“…The largest window of opportunity for making an impact in a cost-effective and efficient manner is during the conceptual design phase [62] (see Figure 7). There is a cost associated with changes made in subsequent phases that increases exponentially with time.…”

“…It is, therefore, more beneficial to engage with professionals responsible for making critical design decisions during the formative stage of a project. The largest window of opportunity for making an impact in a cost-effective and efficient manner is during the conceptual design phase [62] (see Figure 7). There is a cost associated with changes made in subsequent phases that increases exponentially with time.…”