Epidemiology of Zoonotic Coxiella burnetii in The Republic of Guinea.

BACKGROUND: Q fever is a zoonotic infectious disease characterized by fever, malaise, chills, significant weakness, and muscle pain. In some cases, the disease can become chronic and affect the inner membranes of the heart, such as the valves, leading to endocarditis and a high risk of death. Coxiella burnetii (C. burnetii) is the primary causative agent of Q fever in humans. This study aims to monitor the presence of C. burnetii in ticks collected from small mammals and cattle in the Republic of Guinea (RG). METHODS: Rodents were trapped in the Kindia region of RG during 2019-2020, and ticks were collected from cattle in six regions of RG. Total DNA was extracted using a commercial kit (RIBO-prep, InterLabService, Russia) following the manufacturer's instructions. Real-time PCR amplification was conducted using the kit (AmpliSens Coxiella burnetii-FL, InterLabService, Russia) to detect C. burnetii DNA. RESULTS AND CONCLUSIONS: Bacterial DNA was detected in 11 out of 750 (1.4%) small mammals and 695 out of 9620 (7.2%) tick samples. The high number of infected ticks (7.2%) suggests that they are the main transmitters of C. burnetii in RG. The DNA was detected in the liver and spleen of a Guinea multimammate mouse, Mastomys erythroleucus. These findings demonstrate that C. burnetii is zoonotic in RG, and measures should be taken to monitor the bacteria's dynamics and tick prevalence in the rodent population.

Detection of Babesia caballi, Theileria mutans and Th. velifera in ixodid ticks collected from cattle in Guinea in 2017-2018.

Intraerythrocytic protozoan parasites from the genera Babesia and Theileria may infect a wide range of animals and humans. The purpose of this study was to detect the 18S ribosomal RNA gene of Babesia spp. and Theileria spp. in ticks collected from household cows in the Republic of Guinea from 2017 to 2018 by PCR and then genotype the gene fragments by sequencing. A total of 907 ticks from 319 cows were collected in seven prefectures of Guinea (Boke, Faranah, Kankan, Kindia, Labe, Mamou and N'Zerekore). The following tick species on cattle were identified: Amblyomma variegatum (44.2%), Rhipicephalus decoloratus (34.7%), Rh. annulatus (10.3%), Rh. geigyi (7.3%) Hyalomma truncatum (2.4%), Rh. senegalensis (0.8%) and Haemaphysalis leachi (0.6%). Genetic markers for piroplasms were found in Am. variegatum, Rh. decoloratus, Rh. annulatus, and Rh. geigyi ticks, and the total infection rate for these ticks was 4.2%. The highest infection rate was found in Rh. annulatus ticks (10.9%). The piroplasms were genotyped as Babesia caballi, Theileria mutans and Theileria velifera by phylogenetic analysis of the 1150 bp 18S ribosomal RNA gene fragments. These pathogens were discovered in practically all studied prefectures in Guinea except for Mamou Prefecture. We propose that these ixodid ticks might play a major role in the transmission of piroplasm infections in domestic animals in Guinea.

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

Rhipicephalus 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, further invasion of this tick species into other West African countries was identified. In this paper, we describe the first detection of R. microplus in Guinea and list the vector-borne haemoparasites that were detected in the invading 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 the DNA of Babesia bigemina, Anaplasma marginale, Anaplasma platys, and Ehrlichia sp. The results of this study indicate that R. microplus was introduced into Guinea in association with cows from Mali and/or the Ivory Coast.

Ngari virus (Orthobunyavirus, Peribunyaviridae) in ixodid ticks collected from cattle in Guinea.

Ngari virus is a mosquito-borne virus belonging to the genus Orthobunyavirus (Peribunyaviridae family). This virus is pathogenic to humans and causes severe illness. Ngari virus is present in several African countries, including Madagascar. Here, we report the detection of Ngari virus in ixodid ticks collected from cows in Guinea. A tick survey was conducted in March-November of 2018 in six regions of Guinea. The sample comprised 710 pools, with a total of 2067 ticks belonging to five species collected from 197 cows. At the initial stage, we screened a subsample of tick pools of vector-borne viruses with a multiplex genus-specific primer panel. In the second stage of the study, we narrowed the search and screened all the samples by qPCR for the detection of Ngari virus. All positive samples were sequenced with primers flanking Ngari virus-specific fragments on the S and M segments. We found Ngari virus in 12 pools that were formed from engorged ticks collected from livestock in three villages of the Kindia and Kankan regions. Sequencing of the S and M segments confirmed that the detected viruses belong to Ngari virus, and the viruses were most similar to the strain Adrar, which was isolated in Mauritania. We detected viral RNA in ticks of the following species: Amblyomma variegatum, Rhipicephalus geigyi, and Rh. (Boophilus) spp. There is no evidence that ixodid ticks are competent vectors of the Ngari virus. Most likely, the ticks obtained the virus through blood from an infected host. The study of engorged ticks can be recommended as a simpler approach for the wide screening of the Ngari virus and subsequent testing of cattle and mosquitos in those locations where the PCR-positive ticks were collected.

Bombali Virus in Mops condylurus Bats, Guinea.

In 2018, a previously unknown Ebola virus, Bombali virus, was discovered in Sierra Leone. We describe detection of Bombali virus in Guinea. We found viral RNA in internal organs of 3 Angolan free-tailed bats (Mops condylurus) trapped in the city of N'Zerekore and in a nearby village.