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Resistance Status of Anopheles Gambiae S.l. to Insecticides Following the 2011 Mass Distribution Campaign of Long-lasting Insecticidal Nets (LLINs) in the Plateau Department, South-eastern Benin

Abstract

Background: In 2011, Benin's National Malaria Control Programme (NMCP) organized a nationwide mass distribution campaign of LLINs throughout the country. Following this intervention, it was important to assess whether the level of susceptibility of malaria vectors to insecticides had remained the same as compared to the pre-intervention period. The current study investigated this.

Methods: Larval collections were conducted in Ifangni, Sakété, Pobè and Kétou districts located in Plateau department, Southeastern Benin before (2009) and after (2012-2013) LLIN distribution. Anopheles gambiae sensu lato (s.l.) larvae from the 4 study districts were reared to adulthood and WHO susceptibility tests were conducted. The insecticides tested were deltamethrin (0.05%), permethrin (0.75%), bendiocarb (0.1%) and DDT (4%). Molecular species identification as well as, the characterization of the kdr L1014F mutation were also performed in the An. gambiae s.l. complex using PCR method.

Results: Overall, a significant decrease in mortality rates of An. gambiae s.l. to deltamethrin (0.05%), permethrin (0.75%) and DDT (4%) was observed post-LLIN distribution, respectively: (100% vs 80.9%, p < 0.0001), (77.5% vs 70%, p = 0.01) and, (47.8% vs 4.4%, p < 0.0001). By contrast, susceptibility of vectors to bendiocarb (0.1%) remained the same (100% mortality in the WHO susceptibility tube tests) pre- and post-intervention. An increase in the kdr L1014F frequency was observed post-LLIN distribution [F(kdr) = 0.91)] compared to the pre-intervention period [F(kdr) = 0.56], p < 0.0001. Anopheles coluzzii and An. gambiae were the two molecular species identified in the study area.

Conclusion: The decrease susceptibility to pyrethroids and DDT as well as, the increase in the frequency of the kdr L1014F mutation after the intervention stressed at the time, the need for the development and implementation of effective insecticide resistance management strategies. At present, an update of the vectors resistance status in the area is also necessary for decision-making.

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References
1.
Aikpon R, Agossa F, Osse R, Oussou O, Aizoun N, Oke-Agbo F . Bendiocarb resistance in Anopheles gambiae s.l. populations from Atacora department in Benin, West Africa: a threat for malaria vector control. Parasit Vectors. 2013; 6:192. PMC: 3698110. DOI: 10.1186/1756-3305-6-192. View

2.
Reimer L, Fondjo E, Patchoke S, Diallo B, Lee Y, Ng A . Relationship between kdr mutation and resistance to pyrethroid and DDT insecticides in natural populations of Anopheles gambiae. J Med Entomol. 2008; 45(2):260-6. DOI: 10.1603/0022-2585(2008)45[260:rbkmar]2.0.co;2. View

3.
Padonou G, Sezonlin M, Osse R, Aizoun N, Oke-Agbo F, Oussou O . Impact of three years of large scale Indoor Residual Spraying (IRS) and Insecticide Treated Nets (ITNs) interventions on insecticide resistance in Anopheles gambiae s.l. in Benin. Parasit Vectors. 2012; 5:72. PMC: 3379941. DOI: 10.1186/1756-3305-5-72. View

4.
Damien G, Djenontin A, Chaffa E, Yamadjako S, Drame P, Ndille E . Effectiveness of insecticidal nets on uncomplicated clinical malaria: a case-control study for operational evaluation. Malar J. 2016; 15:102. PMC: 4759848. DOI: 10.1186/s12936-016-1156-2. View

5.
Ibrahim S, Manu Y, Tukur Z, Irving H, Wondji C . High frequency of kdr L1014F is associated with pyrethroid resistance in Anopheles coluzzii in Sudan savannah of northern Nigeria. BMC Infect Dis. 2014; 14:441. PMC: 4147187. DOI: 10.1186/1471-2334-14-441. View