[Molecular and genetic characteristics of the multicomponent flavi-like Kindia tick virus (Flaviviridae) found in ixodes ticks on the territory of the Republic of Guinea].

INTRODUCTION: Ixodes ticks are vectors for pathogens of many infectious diseases. Recently, during the study of Rhipicephalus geigyi ticks collected from livestock in the Republic of Guinea, a new multicomponent flavi-like RNA virus, called Kindia tick virus (KITV), was discovered with an unusual mechanism for the implementation of genetic information. The aim of the work is to detect and study the genetic diversity of KITV in ixodes ticks collected in the territory of the Kindia province of the Republic of Guinea. MATERIAL AND METHODS: In 2021, 324 specimens of ticks of the species Amblyomma variegatum, Rh. geigyi, Rh. annulatus, Rh. decoloratus, Rh. senegalensis were collected from cattle. The detection of viral RNA was carried out in individual samples of ticks by RT-PCR, followed by the determination of the nucleotide sequence and phylogenetic analysis. RESULTS AND DISCUSSION: KITV detection rates in ticks of the species Rh. geigyi was 12.2%, Rh. annulatus 4.4%, Rh. decoloratus 3.3%. However, the KITV genetic material has not been identified in Am. variegatum ticks, which are one of the dominant species in West Africa. For all virus isolates, a partial nucleotide sequences of each of the four viral segments (GenBank, OK345271OK345306) were determined. The phylogenetic analysis showed a high level of identity (98.599.8%) for each of the four segments of the viral genome with those previously found in the Republic of Guinea. The obtained KITV isolates are most genetically close to Mogiana tick virus, which was previously detected in South America in Rh. microplus ticks and significantly differed from other multicomponent viruses circulating in Europe and Asia, including the Russian Federation. CONCLUSION: KITV genetic material was found in three species of ixodid ticks collected from livestock in a number of prefectures of the Republic of Guinea. The infection rate in ticks was 3.312.2%. The continuation of research in this direction remains relevant.

Prevalence of Crimean-Congo hemorrhagic fever virus in rural areas of Guinea.

This article presents the results of a comprehensive survey of Guinea with the aim of assessing the burden of Crimean-Congo hemorrhagic fever virus (CCHFV) in rural areas of the country. Human serum samples (n = 2207) were studied using enzyme-linked immunosorbent assay (ELISA) for the presence of specific IgG against CCHFV. In addition, 4273 samples of partially- or fully-engorged ticks from several sources (cattle, domestic and roving dogs, and small mammals) were collected and studied using ELISA and RT-qPCR to detect CCHFV antigen and specific RNA. The data obtained show that 3.0 % of the population in rural Guinea was seropositive, without significant geographical or sexual differences. Seropositive individuals, however, were mainly in the 'active age' group (16-45 years old). Among ticks studied, the estimated prevalence of CCHFV was 1.3 ± 0.4 %. Five out of eight tick species studied were identified as CCHFV carriers in Guinea. Therefore, it can be assumed that the territory of Guinea is a single, continuous, natural focus of CCHFV. This identified medium intensity focus merits further study.

[Formation of focus of West Nile fever on the territory of Saratov Region].

AIM: Detection of circulation of West Nile virus (WNV) on the territory of Saratov Region and prerequisites for formation of natural focus of West Nile fever (WNF), determination of the role of WNV in infectious pathology on the territory of the region. MATERIALS AND METHODS: of organs of small mammals, birds, blood-sucking arthropods for the presence of WNV markers (antigens and/or RNA) were studied. Clinical material from patients with symptoms not excluding WNF was studied. Donor blood sera samples were analyzed with the aim of detection of immune layer against WNV in population of Saratov Region. RESULTS: In 2010 WNV antigens were detected by EIA in 12 samples (7.1%) of mammal organ suspensions. In 2012 by using RT-PCR and EIA, markers of WNV were detected in 6 samples of bird brain suspensions (6.3%) and 1 sample of mammal organ suspension. Immune layer of population against WNV was 4% in 2011, 2.8% in 2012. In 2012 in 11 of 27 examined patients IgM against WNV in diagnostic titers and/or serconversion of IgG in paired sera were detected. In addition in 5 individuals virus RNA was detected in blood. Based on clinical, laboratory data and epidemiologic anamnesis 11 patients were diagnosed with WNF. CONCLUSION: The results obtained give evidence on the circulation of WNV on the territory of Saratov Region in 2010 - 2012. With the development of complications of WNF epidemiologic situation in 2012 an expansion of WNV areal onto the territory of the region took place and the process of formation of WNF natural foci is ongoing.