Extensive new Anopheles cryptic species involved in human malaria transmission in western Kenya

Daibin Zhong,Andrew K Githeko,Guiyun Yan,Ming-Chieh Lee,Solomon Kibret,Xiaoming Wang,Yaw A Afrane,Harrysone Atieli,Guofa Zhou,Elizabeth Hemming-Schroeder

doi:10.1038/s41598-020-73073-5

Daibin Zhong, Andrew K Githeko + Show 8 more

Open Access

https://doi.org/10.1038/s41598-020-73073-5

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Abstract

A thorough understanding of malaria vector species composition and their bionomic characteristics is crucial to devise effective and efficient vector control interventions to reduce malaria transmission. It has been well documented in Africa that malaria interventions in the past decade have resulted in major changes in species composition from endophilic Anopheles gambiae to exophilic An. arabiensis. However, the role of cryptic rare mosquito species in malaria transmission is not well known. This study examined the species composition and distribution, with a particular focus on malaria transmission potential of novel, uncharacterized Anopheles cryptic species in western Kenya. Phylogenetic analysis based on ITS2 and COX1 genes revealed 21 Anopheles mosquito species, including two previously unreported novel species. Unusually high rates of Plasmodium sporozoite infections were detected in An. funestus, An. gambiae and eight cryptic rare species. Plasmodium falciparum, P. malariae and P. ovale sporozoite infections were identified with large proportion of mixed species infections in these vectors. This study, for the first time, reports extensive new Anopheles cryptic species involved in the malaria transmission in western Kenya. These findings underscore the importance of non-common Anopheles species in malaria transmission and the need to target them in routine vector control and surveillance efforts.

Highlights

A thorough understanding of malaria vector species composition and their bionomic characteristics is crucial to devise effective and efficient vector control interventions to reduce malaria transmission
A subset of 21 randomly selected individuals from each major species identified by PCRs were confirmed by internal transcribed spacer 2 (ITS2) sequencing based on similarity (> 98%) to the sequences of anopheline voucher species retrieved from NCBI GenBank database (Supplementary Fig. S2)
Except for two species groups (An. sp.[18] and An. sp.19), the ITS2 sequences of all the species were identified as different species based on their similarity (> 98%) to the sequences of Anopheles voucher species retrieved from NCBI GenBank database (Supplementary Fig. S2)

Summary

Introduction

A thorough understanding of malaria vector species composition and their bionomic characteristics is crucial to devise effective and efficient vector control interventions to reduce malaria transmission. To understand the role of cryptic rare vector species in malaria transmission, the present study examined the composition, distribution, and bionomics of Anopheles species in western Kenya. The study determined Plasmodium sporozoite infection status of cryptic rare Anopheles species in highland and lowland settings of western Kenya.

Results

Conclusion