Insecticide susceptibility of Anopheles coluzzii and Anopheles gambiae mosquitoes in Ibadan, Southwest Nigeria.

The emergence of insecticide resistance in Anopheles (Diptera: Culicidae) mosquitoes has great implications for malaria control in Nigeria. This study aimed to determine the dynamics of insecticide susceptibility levels and the frequency of knock-down resistance (kdr) mutations (L1014F) in wild Anopheles coluzzii Coetzee & Wilkerson sp. n. and Anopheles gambiae Giles from the Ojoo and Bodija areas of Ibadan, in southwest Nigeria. Insecticide susceptibility to pyrethroids, organophosphates, carbamates and organochlorines was assessed using World Health Organization (WHO) bioassays. A subset of the mosquitoes exposed to pyrethroids and DDT was used for species and molecular form identification; kdr genotyping was determined using the TaqMan real-time polymerase chain reaction assay. The mosquitoes were resistant to pyrethroids and DDT but completely susceptible to organophosphates and carbamates. Bodija samples (n = 186) consisted of An. gambiae (91.4%) and An. coluzzii (8.1%) and included one An. coluzzii/An. gambiae hybrid specimen. All mosquitoes screened in Ojoo (n = 26) were An. gambiae. The 1014F kdr mutation was detected at frequencies of 24.5 and 5.8% in Bodija and Ojoo, respectively. No correlation was observed between kdr genotypes and resistance phenotypes. The results indicate that metabolic resistance probably plays an important role in the development of resistance and highlight the need to implement insecticide resistance management strategies.

Application of geographical information system for lymphatic filariasis and malaria control in Nigeria.

Geographical Information System (GIS) is defined as an information system used to capture, store, edit, retrieve, analyze and visualize geographically referenced data. The use of GIS is one technology that is very useful in the prevention and control of Vector Borne Diseases (VBDs) such as lymphatic filariasis (LF) and malaria which cause high morbidity and mortality in Nigeria. This paper focuses on how the use of Geographical Information System (GIS) can be harnessed for surveillance, prevention and control of LF and malaria in Nigeria. GIS can be used as an operational tool to assist with resource allocation, as a monitoring and evaluation tool and as a tool to investigate various research projects on spatial aspects of LF and malaria epidemiology. This paper provides information on the benefits and potential of using GIS as a tool for the national malaria and LF control programmes with particular reference to Nigeria.