Phylogenetic analysis of variants of the Puumala virus (Hantaviridae: Orthohantavirus) circulating in the Saratov region.

The objective is to determine the complete nucleotide sequence and conduct a phylogenetic analysis of genome variants of the Puumala virus isolated in the Saratov region. MATERIALS AND METHODS: The samples for the study were field material collected in the Gagarinsky (formerly Saratovsky), Engelssky, Novoburassky and Khvalynsky districts of the Saratov region in the period from 2019 to 2022. To specifically enrich the Puumala virus genome in the samples, were used PCR and developed a specific primer panel. Next, the resulting PCR products were sequenced and the fragments were assembled into one sequence for each segment of the virus genome. To construct phylogenetic trees, the maximum parsimony algorithm was used. RESULTS: Genetic variants of the Puumala virus isolated in the Saratov region have a high degree of genome similarity to each other, which indicates their unity of origin. According to phylogenetic analysis, they all form a separate branch in the cluster formed by hantaviruses from other subjects of the Volga Federal District. The virus variants from the Republics of Udmurtia and Tatarstan, as well as from the Samara and Ulyanovsk regions, are closest to the samples from the Saratov region. CONCLUSION: The data obtained show the presence of a pronounced territorial confinement of strains to certain regions or areas that are the natural biotopes of their carriers. This makes it possible to fairly accurately determine the territory of possible infection of patients and/or the circulation of carriers of these virus variants based on the sequence of individual segments of their genome.

[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.

[Study of the prevalence of antibodies to some arboviruses in the population of the Republic of Guinea].

INTRODUCTION: Acute febrile diseases kill more than 250,000 people annually in West Africa. Malaria and typhoid fever traditionally occupy most of the total structure of registered fevers. However, these data do not fully reflect the true overall disease patterns in the West African region. This is due to the fact that diagnosis is mainly based on the clinical signs of the infectious process, suggesting that a certain number of diseases may be caused by arboviruses. The detection of specific antibodies (ABs) to infectious pathogens in the blood sera of residents of a particular area is a reliable indicator of the circulation of these pathogens in a particular territory.The aim of this study was to determine the prevalence of antibodies to a number of arboviruses: Dengue (DENV), West Nile (WNV) (family Flaviviridae), Crimean-Congo hemorrhagic fever (orthonairo)virus (CCHFV), Batai (Batai virus), Bhanja (BHAV) (order Bunyavirales), Chikungunya (CHIKV), and Sindbis (SINV) (family Togaviridae) in the population of the Republic of Guinea. MATERIAL AND METHODS: In total, a panel of 2,620 blood serum samples from people living in all landscape and geographical areas of Guinea was collected for the study. Detection of IgG antibodies was performed using an enzyme-linked immunoassay (ELISA). RESULTS: In total, ABs to Batai virus were detected in 144 samples (5.5%), BHAV in 58 (2.2%), WNV in 892 (34.0 %), DENV in 659 (25.2 %), CCHFV in 58 (2.2 %), CHIKV in 339 (12.9 %), and SINV in 52 samples (2.0 %). DISCUSSION: The obtained results indicate serological evidence of the spectrum of arboviruses in the population of all landscape and geographical zones of the Republic of Guinea, confirming their active circulation in this territory. CONCLUSION: Given the high epidemiological significance of arbovirus infectious diseases, it is an urgent task to continue studying its share in the structure of febrile diseases in the territory of the Republic of Guinea.

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.

WEST NILE FEVER IN THE SARATOV REGION IN 2013-2015.

West Nile virus (WNV) circulation in the territory of Saratov region and its role in the infectious pathology were investigated. For this purpose, in studies conducted in 2013-2015, suspensions of bloodsucking arthropods, organs of birds and small mammals were analyzed for the presence of WNV markers (antigens and/or RNA). The seroprevalence level in live-stock animals and population of the region was evaluated; clinical samples from patients with symptoms compatible with West Nile fever (WNF) were analyzed. As a result of the investigations, WNV markers were detected in field samples gathered in natural biotopes and in the city of Saratov. Immunity to WNV was detected in horses. A stable domain of persons with immunity to this agent was revealed among regional population. Patients with WNF have been annually registered in the region since 2012. The obtained results confirm active circulation of WNF in the Saratov region, as well as formation of stable natural and anthropourgic foci.