Toure, A. H. | Search bioRxiv

bioRxiv2020

Rhipicephalus microplus and its vector-borne haemoparasites in Guinea: further species expansion in West Africa

AO_SCPLOWBSTRACTC_SCPLOWRhipicephalus microplus is an ixodid tick with a pantropical distribution that represents a serious threat to livestock. West Africa was free of this tick until 2007, when its introduction into Benin was reported. Shortly thereafter, the further invasion of this tick into West African countries was demonstrated. In this paper, we describe the first detection of R. microplus in Guinea and list the vector-borne haemoparasites that were detected in the invader and indigenous Boophilus species. In 2018, we conducted a small-scale survey of ticks infesting cattle in three administrative regions of Guinea: N`Zerekore, Faranah, and Kankan. The tick species were identified by examining their morphological characteristics and by sequencing their COI gene and ITS-2 gene fragments. R. microplus was found in each studied region. In the ticks, we found DNA of Babesia bigemina, Anaplasma marginale, Anaplasma platys, and Ehrlichia spp. The results of this study indicate that R. microplus was introduced into Guinea with cows from Mali and/or Ivory Coast.

zoology↗

bioRxiv2019

Lassa Virus in the Host Rodent Mastomys Natalensis within Urban Areas of N’zerekore, Guinea

Lassa virus is the causative agent of a dangerous zoonotic disease distributed in West Africa. A primary reservoir host of Lassa virus is Mastomys natalensis. These mice associate closely with humans and are commonly found in villages. Consequently, previous studies of Lassa virus have focused on rural areas. The prevalence of the virus in large cities has not been studied.\n\nWe conducted a study in NZerekore city, which has a population of approximately 300,000 residents. Small mammals were captured during a pilot study in May, and the main study was performed in August 2018. Based on the pilot study, we designed and implemented a stratified random sample to investigate the prevalence of Lassa virus among M. natalensis in NZerekore. The total sampling efforts consisted of 45 and 985 trapping nights in May and August, respectively. Samples of rodent tissues were screened for Lassa virus by RT-PCR.\n\nIn May, we trapped 20 rodents, including 19 M. natalensis. Viral RNA was detected in 18 M. natalensis. In August, 149 small mammals were captured, including 43 M. natalensis. The prevalence of Lassa virus among M. natalensis in NZerekore was 23.3% (CI 95%: 11.8-38.6%). Sequencing showed that the isolates belonged to lineage IV. We detected four Lassa virus hotspots located in different parts of the city. The largest Lassa virus hotspot was found in the neighborhood of the central market, which suggests that the virus was originally introduced into the city through the market.

epidemiology↗