Dynamics of multiple insecticide resistance in the malaria vector Anopheles gambiae in a rice growing area in South-Western Burkina Faso

• Published in: Malaria Journal
• Main Authors: Ouédraogo Jean-Bosco, N'Guessan Raphaël, Ouari Ali, Djogbenou Luc, Diabaté Abdoulaye, Dabiré Kounbobr, Hougard Jean-Marc, Chandre Fabrice, Baldet Thierry
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMC 2008
• Subjects: Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Arctic
• Online Access: https://doi.org/10.1186/1475-2875-7-188; https://doaj.org/article/c9b758a6fc7349b08176369bd9efcc18

Abstract Background Insecticide resistance of the main malaria vector, Anopheles gambiae , has been reported in south-western Burkina Faso, West Africa. Cross-resistance to DDT and pyrethroids was conferred by alterations at site of action in the sodium channel, the Leu-Phe kdr mutation; resistance to organophosphates and carbamates resulted from a single point mutation in the oxyanion hole of the acetylcholinesterase enzyme designed as ace-1 R . Methods An entomological survey was carried out during the rainy season of 2005 at Vallée du Kou, a rice growing area in south-western Burkina Faso. At the Vallée du Kou, both insecticide resistance mechanisms have been previously described in the M and S molecular forms of An. gambiae . This survey aimed i) to update the temporal dynamics and the circumsporozoite infection rate of the two molecular forms M and S of An. gambiae ii) to update the frequency of the Leu-Phe kdr mutation within these forms and finally iii) to investigate the occurrence of the ace-1 R mutation. Mosquitoes collected by indoor residual collection and by human landing catches were counted and morphologically identified. Species and molecular forms of An. gambiae , ace-1 R and Leu-Phe kdr mutations were determined using PCR techniques. The presence of the circumsporozoite protein of Plasmodium falciparum was determined using ELISA. Results Anopheles gambiae populations were dominated by the M form. However the S form occurred in relative important proportion towards the end of the rainy season with a maximum peak in October at 51%. Sporozoite rates were similar in both forms. The frequency of the Leu-Phe kdr mutation in the S form reached a fixation level while it is still spreading in the M form. Furthermore, the ace - 1 R mutation prevailed predominately in the S form and has just started spreading in the M form. The two mutations occurred concomitantly both in M and S populations. Conclusion These results showed that the Vallée du Kou, a rice growing area formerly occupied mainly by M ...