First confrmed occurrence of the yellow fever virus and dengue virus vector Aedes (Stegomyia) luteocephalus (Newstead, 1907) in Mozambique

Abstract

BACKGROUND: Mozambique, same as many other tropical countries, is at high risk of arthropod-borne virus (arbovirus) diseases and recently two dengue virus (DENV) outbreaks occurred in the northern part of the country. The occurrence of some important vector species, such as Aedes (Stegomyia) aegypti (Linnaeus) and Ae. (Stg.) albopictus (Skuse), besides several other sylvatic vectors, have been reported in the country, which may indicate that the transmission of some arboviruses of public health importance may involve multiple-vector systems. Therefore, knowing the occurrence and distribution of existing and the new important vectors species, is crucial for devising systematic transmission surveillance and vector control approaches. The aim of this study was to map the occurrence and distribution of mosquito species with potential for transmitting arboviruses of human and veterinary relevance in Niassa Province, Northern Mozambique. METHODS: Field entomological surveys were undertaken in April 2016 in Lago District, Niassa Province, northern Mozambique. Breeding sites of mosquitoes were inspected and immature stages were collected and reared into adult. Mosquitoes in the adult stages were morphologically identifed using taxonomic keys. Morphological identifcation of Aedes (Stegomyia) luteocephalus (Newstead) were later confrmed using dissected male genitalia and molecular based on the phylogenetic analyses of the sequenced barcode (cox1 mtDNA) gene. RESULTS: A total of 92 mosquito larvae collected developed into adults. Of these, 16 (17.39%) were morphologically identifed as Ae. luteocephalus. The remaining specimens belonged to Ae. (Stg.) aegypti (n=4, 4.35%), Ae. (Aedimorphus) vittatus (n=24, 26.09%), Anopheles garnhami (n=1, 1.09%), Culex (Culiciomyia) nebulosus (n=28, 30.43%), Eretmapodites subsimplicipes (n=18, 19.57%) and Toxorhynchites brevipalpis (n=1, 1.09%), taxa already known to the country. Male genitalia and phylogenetic analyses confrmed the identity of Ae. luteocephalus specimens collected in this study. CONCLUSIONS: To our knowledge, this is the frst detection of Ae. luteocephalus in Mozambican territory, a vector species of yellow fever virus (YFV), Zika virus (ZIKV) and dengue virus (DENV) in Africa. Further studies are encouraged to investigate the role of Ae. luteocephalus in the transmission of arboviral diseases in Mozambique.