Next generation sequencing improves the resolution of detecting mixed host blood meals sources in field collected arboviral mosquito vectors

Authors: TCHOUASSI, DAVID - International Centre Of Insect Physiology And Ecology; KISERO, ROBINSON - International Centre Of Insect Physiology And Ecology; ROTICH, GILBERT - International Centre Of Insect Physiology And Ecology; Dunlap, Christopher; TORTO, BALDWYN - International Centre Of Insect Physiology And Ecology; Muturi, Ephantus

Submitted to: Medical and Veterinary Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/1/2024
Publication Date: 5/15/2024
Citation: Tchouassi, D.P., Kisero, R.O., Rotich, G., Dunlap, C.A., Torto, B., Muturi, E.J. 2024. Next generation sequencing improves the resolution of detecting mixed host blood meals sources in field collected arboviral mosquito vectors. Medical and Veterinary Entomology. https://doi.org/10.1111/mve.12725.
DOI: https://doi.org/10.1111/mve.12725

Interpretive Summary: Mosquitoes transmit some of the world’s most devastating diseases such as malaria, dengue, and yellow fever. Mosquitoes acquire these diseases from an infected human or animal host during a blood meal and transmit them to a susceptible host during a subsequent blood meal. More than 100 species of mosquitoes are known to transmit diseases and each species has its preferred blood meal hosts. Therefore, knowing the animal hosts that different mosquito species feed on is critical to understanding the role of different mosquito species in transmission of disease-causing pathogens. We developed a method for mosquito blood meal identification using next-generation sequencing (NGS). Unlike conventional blood meal analysis approaches, this NGS method can process large number of samples within a short time and can reliably identify mosquito blood meal hosts including blood meals taken from multiple animal hosts in a single egg-laying cycle. This method can be used to improve surveillance and control of mosquito-borne diseases through accurate and rapid identification of mosquito species that pose the greatest threat to the transmission of mosquito-borne diseases.

Technical Abstract: Accurate knowledge of blood meal hosts of different mosquito species is critical for identifying potential vectors and establishing the risk of pathogen transmission. We compared the performance of Miseq next generation sequencing approach relative to conventional sanger sequencing approach in identification of mosquito blood meals using genetic markers targeting the 12S rRNA and cytochrome oxidase I (COI) genes. We analysed the blood meals of three mosquito vector species (Aedes aegypti, Aedes bromeliae and Culex pipiens s.l.) collected outdoors, and compared the frequency of single-versus multiple-blood feeding. Single host blood meals were mostly recovered for Sanger-based sequencing of the mitochondrial 12S rRNA gene whereas Miseq sequencing employing this marker and the COI marker detected both single and multiple blood meal hosts in individual mosquitoes. Multiple blood meals (two or more hosts) which mostly included humans were detected in 19–22.7% of Ae. aegypti samples. Most single host blood meals for this mosquito species were from humans (47.7–57.1%) and dogs (9.1–19.0%), with livestock, reptile and rodent hosts collectively accounting for 4.7–28.9% of single host blood meals. The frequency of two or more host blood meals in Ae. simpsoni s.l. was 26.3–45.5% mostly including humans, while single host blood meals were predominantly from humans (31.8-47.4%) with representation of rodent, reptile, and livestock blood meals (18.2-68.2%). Single host blood meals from Cx. pipiens s.l. were mostly from humans (27.0-39.4%) and cows (11.5-27.36%). Multiple blood meal hosts that mostly included humans occurred in 21.2-24.4% of Cx. pipiens s.l. samples. Estimated human biting rates ranged from 53–76% for Ae. aegypti, 32–82% for Ae. simpsoni s.l. and 26–61% for Cx. pipiens s.l. and were consistently lower for Sanger-based sequencing approach compared to Miseq-based sequencing approach. These findings demonstrate that Miseq sequencing approach is superior to sanger sequencing approach as it can reliably identify mixed host blood meals in a single mosquito, improving our ability to understand the transmission dynamics of mosquito-borne pathogens.