Updating Anopheles funestus group members in Burkina Faso: species distribution and contribution to malaria transmission.

BACKGROUND

Anopheles funestus group and Anopheles gambiae complexes are among the most efficient malaria vectors in Africa, thriving in a variety of environments and well adapted to develop in semi-permanent and permanent water bodies. This study investigated the spatial distribution of the An. funestus group and their contribution to malaria transmission in Burkina Faso.

METHODS

An entomological survey was conducted from October to December 2022 across 67 sites within the ecological zones of Burkina Faso (once a month); An. funestus was detected in 22 of these sites. Mosquitoes were collected using pyrethrum spray catches (PSC) and identified at the species complex level using morphological keys. A polymerase chain reaction (PCR) was performed for species identification among An. funestus group, blood meal sources and Plasmodium falciparum infection.

RESULTS

A total of 617 members of the An. funestus group (45 males and 572 females) were collected across eight regions of Burkina Faso. Anopheles funestus s.s. was the most prevalent specie identified with a frequency of up to 95% (589/617). Most An. funestus s.s. were found in the Hauts-Bassins and the Sud-Ouest regions with 30% (177/589) and 55% (329/589), respectively. Hybrids between An. rivulorum and An. rivulorum-like were identified at a frequency of 3.57% (22/617). Additionally, results showed a high prevalence of zoophilic behaviour (64.3% of the blood source) in An. funestus. Plasmodium falciparum infection was detected in 5.76% (33/572) of the An. funestus s.l. populations with a frequency of 5.6% (32/572) and 0.174% (1/572) in An. funestus s.s. and An. rivulorum-like, respectively.

CONCLUSIONS

This study updates the distribution of the An. funestus group and its potential role in malaria transmission in Burkina Faso. It emphasizes the need to strengthen malaria vector surveillance and highlights the importance of incorporating An. funestus in developing innovative vector control interventions.