AVAILABILITY OF DATA AND MATERIALS :
All data generated or analyzed during this study are included in this article and its additional files.ADDITIONAL FILE 1: FIGURE S1. Host-biting networks for A) reserve network and B) rural network of mosquitoes and their vertebrate hosts from the north-eastern KZN.ADDITIONAL FILE 2: FIGURE S2. The phylogenetic tree generated using from 64 mosquito sequences of COI was inferred by the Maximum Likelihood method and Tamura-Nei model with 1000 bootstrap replicates.ADDITIONAL FILE 3: TABLE S1. Generated mosquito sequences, their GenBank (Submission: SUB14487250) accession numbers, highest percentage similarity to their homologous sequences and query covers.BACKGROUND :
Rift Valley fever virus (RVFV) is a zoonotic mosquito-borne virus with serious implications for livestock health, human health, and the economy in Africa, and is suspected to be endemic in north-eastern KwaZulu-Natal (KZN), South Africa. The vectors of RVFV in this area are poorly known, although several species, such as Aedes (Neomelaniconion) mcintoshi, Aedes (Neomelaniconion) circumluteolus, Aedes (Aedimorphus) durbanensis, and Culex (Lasioconops) poicilipes may be involved. The aim of the study was to determine the vertebrate blood meal sources of potential RVFV mosquito vectors in north-eastern KZN and to characterize the host-biting network.
METHODS :
Blood-fed mosquitoes were collected monthly from November 2019 to February 2023 using a backpack aspirator, CO2-baited Centers for Disease Control and Prevention (CDC) miniature light traps and tent traps, in the vicinity of water bodies and livestock farming households. The mosquitoes were morphologically identified. DNA was extracted from individual mosquitoes and used as templates to amplify the vertebrate cytochrome c oxidase I (COI) and cytochrome b (cytb) genes using conventional polymerase chain reaction (PCR). Amplicons were sequenced and queried in GenBank and the Barcode of Life Data systems to identify the vertebrate blood meal sources and confirm mosquito identifications. All mosquitoes were screened for RVFV using real time reverse transcription (RT)-PCR.
RESULTS :
We identified the mammalian (88.8%) and avian (11.3%) blood meal sources from 409 blood-fed mosquitoes. Aedes circumluteolus (n = 128) made up the largest proportion of collected mosquitoes. Cattle (n = 195) and nyala (n = 61) were the most frequent domestic and wild hosts, respectively. Bipartite network analysis showed that the rural network consisted of more host-biting interactions than the reserve network. All mosquitoes tested negative for RVFV.
CONCLUSIONS :
Several mosquito species, including Ae. circumluteolus, and vertebrate host species, including cattle and nyala, could play a central role in RVFV transmission. Future research in this region should focus on these species to better understand RVFV amplification.The project depicted was sponsored by the US Department of Defense, Defense Threat Reduction Agency. AgriSETA and National Research Foundation of South Africa.https://parasitesandvectors.biomedcentral.com/hj2024Centre for Veterinary Wildlife StudiesMedical VirologyProduction Animal StudiesSDG-03:Good heatlh and well-bein
