The Prevalence and Genetic Variants of the CCHF Virus Circulating among Ticks in the Southern Regions of Kazakhstan.

Crimean-Congo hemorrhagic fever (CCHF) disease cases are registered annually in endemic regions of Kazakhstan. To study the prevalence of various Crimean-Congo hemorrhagic fever virus (CCHFV) genotypes, a total of 694 ticks were collected from southern regions of Kazakhstan in 2021. Hyalomma marginatum (n = 323) (46.5%), Hyalomma anatolicum (n = 138) (19.9%), Hyalomma asiaticum (n = 126) (18.2%), Hyalomma scupense (n = 80) (11.5%) and Ixodes ricinus (n = 27) (3.9%) were collected using the standardized flagging technique from the environment. All the tick samples were analyzed for the presence of CCHFV RNA by RT-PCR. The CCHF-positive samples were found within three Hyalomma asiaticum and one Ixodes ricinus tick sample. For the first time in Kazakhstan, infection of the Ixodes ricinus tick with CCHFV was detected. The results of sequencing and analysis of the S-gene fragment showed that the Asia 1 and Asia 2 CCHF genotypes circulate in the southern regions of Kazakhstan. Viruses isolated in the Zhambyl and Turkestan regions are assigned to the Asia-2 genotype, whereas the virus isolated in the Kyzylorda region to the Asia-1 genotype.

Evidence for flock transmission of individual subtypes and strains of avian influenza viruses: A monitoring study of wild birds in Kazakhstan.

An active surveillance study of avian influenza viruses (AIVs) in wild birds was carried out in Kazakhstan in 2018-2019. In total, 866 samples were collected from wild birds and analyzed for influenza viruses using molecular and virological tests. Genome segments of Asian, European, and Australian lineages were detected in 25 (4.6%) out of 541 waterfowl samples positive for subtype H3N8, and in two (0.6%) out of 325 H3N8 positive samples from terrestrial birds. No highly pathogenic avian influenza virus (AIV) was detected. The results indicated transmission of closely related strains or identical subtypes of AIVs by a flock-unit of migratory birds or annual cyclical pattern of subtype dominance. The simultaneous circulation of genome segments of the Asian, European and Australian genetic lineages of H3N8 AIVs in wild birds in Kazakhstan indicated the important role of Central Asia as a transmission hub of AI viruses linking the East Asian migratory flyways with European flyways and vice versa.

New oligonucleotide microarray for rapid diagnosis of avian viral diseases.

BACKGROUND: We developed a new oligonucleotide microarray comprising 16 identical subarrays for simultaneous rapid detection of avian viruses: avian influenza virus (AIV), Newcastle disease virus (NDV), infection bronchitis virus (IBV), and infectious bursal disease virus (IBDV) in single- and mixed-virus infections. The objective of the study was to develop an oligonucleotide microarray for rapid diagnosis of avian diseases that would be used in the course of mass analysis for routine epidemiological surveillance owing to its ability to test one specimen for several infections. METHODS AND RESULTS: The paper describes the technique for rapid and simultaneous diagnosis of avian diseases such as avian influenza, Newcastle disease, infectious bronchitis and infectious bursal disease with use of oligonucleotide microarray, conditions for hybridization of fluorescent-labelled viral cDNA on the microarray and its specificity tested with use of AIV, NDV, IBV, IBDV strains as well as biomaterials from poultry. Sensitivity and specificity of the developed microarray was evaluated with use of 122 specimens of biological material: 44 cloacal swabs from sick birds and 78 tissue specimens from dead wild and domestic birds, as well as with use of 15 AIV, NDV, IBV and IBDV strains, different in their origin, epidemiological and biological characteristics (RIBSP Microbial Collection). This microarray demonstrates high diagnostic sensitivity (99.16% within 95% CI limits 97.36-100%) and specificity (100%). Specificity of the developed technique was confirmed by direct sequencing of NP and M (AIV), VP2 (IBDV), S1 (IBV), NP (NDV) gene fragments. CONCLUSION: Diagnostic effectiveness of the developed DNA microarray is 99.18% and therefore it can be used in mass survey for specific detection of AIV, NDV, IBV and IBDV circulating in the region in the course of epidemiological surveillance. Rather simple method for rapid diagnosis of avian viral diseases that several times shortens duration of assay versus classical diagnostic methods is proposed.