Molecular identification and wing variations among malaria vectors in Akure North Local Government Area, Nigeria

Abstract

Members of the Anopheles gambiae complex and Anophelesfunestus group are significant vectors of the malaria parasite Plasmodium species in the Afro-tropical region of the world. Molecular identification and variation in the wing were studied among female An.Gambiae complex and An. funestus group, to investigate morphological variations in the wing of local vectors populations of adult female mosquitoes found in five different locations in Akure North Local Government Area of Ondo State (Oba—Ile, Igoba, Isinigbo, Ita—Ogbolu and Iju). The variations in the wing character were found in the 3rd main dark spot area (Pre-apical dark spot—character 8) on the coastal region (Vein region I) of Anopheles gambiae complex wing; with two types (A and B) of wings identified with An. gambiae complex in the study area. Molecular study shows that all the wing type A are Anopheles gambiae s.s., they represent 53.39% of the total An. gambiae complex in the study area. Some of the Anopheles gambiae s.s. (28.30%) and all An. arabiensis (18.30%) were found with wing type B. Among 750 individual Anopheles mosquito species identified using Polymerase Chain Reaction (PCR method), 433 samples representing 57.73% were An. gambiae s.s. while 97 (12.93%) samples were An. arabiensis. Anopheles leesoni was the only member of the An. funestus group identified in the study area. Anopheles leesoni mosquitoes identified in the study location were 182, representing 24.27% of the total Anopheles mosquito species identified using the molecular method. Anopheles gambiae s.s., An. arabiensis, and An. leesoni are only Anopheles mosquito species responsible for malaria transmission in the study area. Anopheles leesoni was the only member of the An. funestus group identified in the study area.

Revolutionizing Malaria Vector Control: The Importance of Accurate Species Identification through Enhanced Molecular Capacity

“…Although these suggest that utilizing molecular techniques in vector management is gaining ground in sub-Saharan Africa, this is not without some attending challenges and limitations. Some of the challenges associated with using molecular identification methods for studying mosquito vectors in SSA are as follows: the presence of species complexes in Anopheles vectors making it difficult to distinguish between sibling species (isomorphic species) using morphological methods alone [188], the lack of adequate funding for vector control activities in malariaendemic nations, which limits the implementation of molecular identification methods [14], the need for specialized equipment and expertise to perform molecular identification, which is often unavailable in all regions of SSA [190], the lack of comprehensive databases of molecular markers for all mosquito vector species in sub-Saharan Africa, which can make it difficult to identify unknown or newly emerging vector species [150], and the susceptibility of mosquitoes in sub-Saharan Africa to presently employed vector control techniques needing to be examined rapidly [191] and incorporated into malaria control programs, particularly in the face of the pressing global elimination drive.…”

“…As a result, most previous research seeking to prevent malaria by characterizing mosquitoes relied more on morphological characterization than molecular characterization [ 187 ]. A prior study, however, showed that morphological characterization is susceptible to several restrictions that make it difficult to correctly identify malaria vectors, which results in the incorrect treatment of malaria vectors in specific regions [ 188 ]. Some African regions where malaria is endemic include Nigeria, the Democratic Republic of the Congo, Uganda, Mozambique, Zimbabwe, and South Africa [ 189 ].…”

“…There are several ongoing studies on the molecular identification and categorization of malaria carriers in sub-Saharan Africa (SSA), as evident in the published literature. Some of the studies include molecular technologies and genetic methodologies developed to investigate the genetic structure of important mosquito vectors in SSA [ 190 ], the use of genetic and morphological techniques for the molecular classification of various and unidentified mosquito vectors in the western Kenyan highlands [ 150 ], the characterization of potential Plasmodium vivax vectors using molecular and morphological methods in central and eastern Sudan [ 191 ], genetic characterization, the composition of species and dispersion maps of mosquito species in Benue State, Nigeria [ 5 ], the molecular identification of the Anopheles nili group of African malaria vectors, which are recognized to be important malaria carriers in SSA [ 124 ], and genetic classification and wing distinctions amongst mosquito vectors in the Akure North Local Government Area, Nigeria, which focuses on the main vector of Plasmodium in Africa, the Anopheles gambiae complex [ 188 ]. Although these suggest that utilizing molecular techniques in vector management is gaining ground in sub-Saharan Africa, this is not without some attending challenges and limitations.…”

Physico-chemical characterization of Anopheles gambiae s.l. breeding sites and kdr mutations in urban areas of Cotonou and Natitingou, Benin

“…This alarming situation underscores the urgent need to intensify prevention and control efforts across the continent. Malaria control primarily involves managing three interconnected entities: humans (the secondary host), Anopheles mosquitoes (the primary host), and the aquatic stages of the vector (eggs, larvae, and pupae) confined to specific habitats [2].…”