Browsing by Author "Noutcha, M. A. E."

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Anopheles gambiae complex: Molecular forms and occurrence of the KDR gene in rural Southwestern Nigeria
(Ibadan, Entomological Society of Nigeria, 2011) Noutcha, M. A. E.; Anumudu, C. I.
An investigation focusing on the molecular forms of Anopheles gambiae complex and occurrence of the knockdown resistance (kdr gene) was carried out from June to July 2001 and August to September 2002 at Igbo-Ora, Nigeria usirig aspirator and DNA analyses. Of the 127 An. gambiae s. l. analysed, there were 66 (51:9%)M and 61 (48.03%) S forms, both recorded in An. gambiae s.s. and Anopheles arabiensis. The forms were virtually sympatric throughout the study. Two of the An. gambiae s.s. examined harboured the kdr gene (RR, RS). The occurrence of the kdr gene at Igbo-Ora indicated the existence of the gene in the savanna woodland populations; earlier records were from the rain forest and Guinea savanna. The implications of these results, within the context of incipient speciation in Anopheles gambiae s.s. are discussed.
Entomological indices of Anopheles gambiae sensu lato at a rural community in south-west Nigeria
(National Institute of Malaria Research, New Delhi on behalf of Indian Council of Medical Research, 2009) Noutcha, M. A. E.; Anumudu, C. I.
Background & objectives: Investigations were conducted to obtain key entomological indices of Anopheles gambiae s.l. at Igbo-Ora, a rural community in south-west Nigeria. Methods: Mosquitoes were caught daily for a week from rooms where tenants had slept the previous night in each of the four months June, July (2001), and August, September (2002). Anopheles gambiae s.l. sibling species were PCR-identified, the blood meal origin was determined by direct ELISA, and the circumsporozoite antigen by sandwich ELISA. Mean weekly rates were calculated. Results: The mean human biting rates were 0.90 and 1.6 in 2001 and 2002 respectively. The mean weekly anthropophilic rates for An. gambiae s.l. were 82 and 86% in 2001 and 2002 respectively; they were high in An. gambiae s.s., An. arabiensis and non-identified species in the complex. The mean weekly circumsporozoite rates were 6.70% in 2001 and 6.30% in 2002. The mean weekly entomological inoculation rates (EIR) were 4.95 and 5.05 in 2001 and 2002 respectively; the seasonal (6-month) rates were high: 128.7 in 2001 and 131.3 in 2002, compared to data from other rural communities on the continent. Interpretation & conclusion: The implications of these findings on the role of An. gambiae s.l. in the holoendemicity of malaria at Igbo-Ora are discussed.
Genetic variants of Plasmodium falciparum infective Anopheles gambiae s.l. at a rural community in southwest Nigeria
(Faulty of Science, University of Port Harcourt, Nigeria., 2009) Noutcha, M. A. E.; Ngoundou-Landji, J.; Anumudu, C. I.
During studies on the epidemiology of malaria at a rural community, Igbo-Ora, Southwest Nigeria, genotyping of Plasmodium falciparum extracted from infective Anopheles gambiae s.l. was undertaken. Circumsporozoite (CSP) ELISA was used on crushes from head-thorax for DNA extraction and PCR amplification for the determination of P. falciparum genotypes on merozoite surface protein-I and 2 (MSP-I & 2). Of the 65 infective anophelines, P. falciparum genotypes were positively identified in 41. Mono-infections constituted 73.4% of all infections; the dominant mono-infections on MSP-1 and MSP-2 were MAD20 (18) and ICI (09) respectively; the rare RO33 (01) was recorded. Double infections were 20.20% (09) with both markers, while only one triple infection was observed on MSP-1. An anopheles was found with two double infections, one on each of the two blocks. Eight of the 12 multiple infections were on MSP-1, five on both MSP-1 and MSP-2. In addition to the multiplicity of proteins in these vectors, size polymorphism was observed in alleles, indicating vector/parasite interactions and environmental variations. These results were compared to those from human sera.
Variations in species composition and infection rates in Anopheles gambiae s.l. across eco-vegetational zones in Nigeria and Cameroon
(National Institute of Malaria Research, New Delhi on behalf of Indian Council of Medical Research, 2010-03) Noutcha, M. A. E.; Anumudu, C. I.