Multi-Marker Mitochondrial DNA Analysis Reveals Broad Vertebrate Host Use by Mansonia Mosquitoes in Baringo County,...

Mosquitoes of the genus Mansonia are widely distributed in wetland ecosystems of sub-Saharan Africa and feed on humans and domestic animals, creating opportunities for zoonotic pathogen transmission. We characterized vertebrate host use by Mansonia africana and M. uniformis in Baringo County, Kenya, evaluated three mitochondrial markers for blood-meal identification, and screened blood-fed and unfed mosquitoes for detectable arboviral RNA.

Mosquito sampling was conducted at Logumgum, Sandai, and Ntepes in 2019 and 2020 using CO₂-baited CDC light traps. Mansonia mosquitoes were recovered from all three sites in 2019 but only from Ntepes in 2020. Blood-fed specimens were analyzed using cytochrome b (cytb), cytochrome oxidase I (cox-1), and vertebrate 16S rRNA in 2019 (vert 16S rRNA), whereas cytb alone was applied in 2020. Blood-fed and unfed mosquitoes were screened for arboviral RNA using pan-RT-PCR assays.

Of 802 blood-fed mosquitoes analyzed in 2019, host-identification success was highest with cytb (87.9%), followed by cox-1 (20.3%) and vert 16S rRNA (5.5%). The additional loci increased overall host resolution by approximately 12% beyond cytb alone. In the 2019 cytb-based dataset, human DNA was detected in 61.8% of identified blood meals when mixed human-animal feeds were included. Separately, 63 of 69 identified blood meals (91.3%) from Ntepes in 2020 were goat-derived. Ma. africana and Ma. uniformis exhibited overlapping host-use profiles. No arboviral RNA was detected.

Ma. africana and Ma. uniformis in Baringo County fed on humans, livestock, rodents, and other vertebrates and showed broadly overlapping host-use profiles. Cytb provided the highest blood-meal identification success, while cox-1 and vert 16S rRNA resolved additional meals, supporting the complementary value of a multilocus approach. Feeding across the human-livestock interface identifies potential exposure pathways supporting the continued inclusion of both species in integrated entomological and One Health surveillance.