Entomological longitudinal surveys in two contrasted eco-climatic settings in Cameroon reveal a high malaria transmission from Anopheles funestus associated with GSTe2 metabolic resistance

BMC Infectious Diseases

Research

Jeannette Tombi¹  Lucia Nkengazong²  Benjamin D. Menze³  Leon M. J. Mugenzi³  Daniel Nguiffo-Nguete³  Magellan Tchouakui³  Derrick Fofie⁴  Brice Natchema S. Fonkou⁴  Charles S. Wondji⁵ 

[1]Faculty of Sciences, University of Yaoundé I, Yaoundé, Cameroon

[2]Institute of Medical Research and Medicinal Plants Studies, (IMPM, P.O.Box 13033), Yaoundé, Cameroon

[3]Medical Entomology Department, Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon

[4]Medical Entomology Department, Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon

[5]Faculty of Sciences, University of Yaoundé I, Yaoundé, Cameroon

[6]Medical Entomology Department, Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon

[7]Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, L3 5QA, Liverpool, UK

关键词: An. funestus;    Sporozoite infection;    Malaria transmission;    Entomological inoculation rate;    GSTe2;    Cameroon;   

DOI  :  10.1186/s12879-023-08698-8

 received in 2023-05-27, accepted in 2023-10-11,  发布年份 2023

来源: Springer

【 摘 要 】

BackgroundThe impact of metabolic resistance to insecticides on malaria transmission remains poorly characterised notably through application of entomological parameters. The lack of resistance markers has been one of the limiting factors preventing a robust assessment of such impact. To this end, the present study sought to investigate how the L119F-Gste2 metabolic gene influences entomological parameters underpinning mosquitos’ propensity to transmit Plasmodium spp.MethodsLongitudinal studies were carried out in Mibellon and Elende, two different eco-climatic settings in Cameroon and mosquitoes were collected using Human Landing Catch (HLC), Centre for Disease Control Light Trap (CDC-LT) and Pyrethrum Spray Catch (PSC) technics. Plasmodium sporozoite parasites were detected by TaqMan and Nested PCR, and blood meal origin by ELISA. The allele-specific PCR (AS-PCR) method was used to genotype the L119F-GSTe2 marker and association with malaria transmission was established by comparing key transmission parameters such as the Entomological Inoculation Rate (EIR) between individuals with different L119F-GSTe2 genotypes.ResultsAn. funestus s.l was the predominant malaria vector collected during the entomological survey in both sites (86.6% and 96.4% in Elende and Mibellon, respectively) followed by An. gambiae s.l (7.5% and 2.4%, respectively). Sporozoite infection rates were very high in both collection sites (8.7% and 11% in Elende and Mibellon, respectively). An. funestus s.s exhibited a very high entomological inoculation rate (EIR) (66 ib/h/month and 792 ib/h/year) and was responsible for 98.6% of all malaria transmission events occurring in both sites. The Human Blood Index was also high in both locations (HBI = 94%). An. funestus s.s. mosquitoes with both 119 F/F (RR) and L119F (RS) genotypes had a significantly higher transmission intensity than their susceptible L/L119 (SS) counterparts (IRR = 2.2, 95%CI (1.1–5.2), p = 0.03; IRR = 2.5, 95% CI (1.2–5.8), p = 0.01 respectively).ConclusionThis study highlights the major role that An. funestus s.s plays in malaria transmission in Cameroon with an aggravation from GSTe2-based metabolic resistance.

【 授权许可】

CC BY   
© The Author(s) 2023

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