Vaccination with live attenuated vaccines is a key element in the prevention of lumpy skin disease. The mechanism of virus attenuation by long-term passaging in sensitive systems remains unclear. Targeted inactivation of virulence genes is the most promising way to obtain attenuated viruses. Four virulence genes in the genome of the lumpy skin disease virus (LSDV) Dermatitis nodulares/2016/Atyrau/KZ were sequentially knocked out by homologous recombination under conditions of temporary dominant selection. The recombinant LSDV Atyrau-5BJN(IL18) with a knockout of the LSDV005, LSDV008, LSDV066 and LSDV142 genes remained genetically stable for ten passages and efficiently replicated in cells of lamb testicles, saiga kidney and bovine kidney. In vivo experiments with cattle have shown that injection of the LSDV Atyrau-5BJN(IL18) at a high dose does not cause disease in animals or other deviations from the physiological norm. Immunization of cattle with the LSDV Atyrau-5BJN(IL18) induced the production of virus-neutralizing antibodies in titers of 4–5 log2. The challenge did not cause disease in immunized animals. The knockout of four virulence genes resulted in attenuation of the virulent LSDV without loss of immunogenicity. The recombinant LSDV Atyrau-5BJN(IL18) is safe for clinical use, immunogenic and protects animals from infection with the virulent LSDV.

In the winter of 2023/2024, the mass death of swans was observed on Lake Karakol on the eastern coast of the Caspian Sea. From 21 December 2023 to 25 January 2024, 1132 swan corpses (Cygnus olor, Cygnus cygnus) were collected and disposed of on the coast by veterinary services and ecologists. Biological samples were collected from 18 birds for analysis at different dates of the epizootic. It was found that the influenza outbreak was associated with a high concentration of migrating birds at Lake Karakol as a result of a sharp cold snap in the northern regions. At different dates of the epizootic, three avian influenza A/H5N1 viruses of clade 2.3.4.4.b were isolated from dead birds and identified as highly pathogenic viruses (HPAIs) based on the amino acid sequence of the hemagglutinin multi-base proteolytic cleavage site (PLREKRRRKR/G). A phylogenetic analysis showed that the viruses isolated from the swans had reassortations in the PB2, PB1, and NP genes between highly pathogenic (HP) and low-pathogenic (LP) avian influenza viruses. Avian influenza viruses A/Cygnus cygnus/Karakol lake/01/2024(H5N1) and A/Mute swan/Karakol lake/02/2024(H5N1) isolated on 10 January 2024 received PB2, PB1, and NP from LPAIV, while A/Mute swan/Mangystau/9809/2023(H5N1) isolated on 26 December 2023 received PB1 and NP from LPAIV, indicating that the H5N1 viruses in this study are new reassortants. All viruses showed amino acid substitutions in the PB2, PB1, NP, and NS1 segments, which are critical for enhanced virulence or adaptation in mammals. An analysis of the genomes of the isolated viruses showed that bird deaths during different periods of the epizootic were caused by different reassortant viruses. Kazakhstan is located at the crossroads of several migratory routes of migratory birds, and the possible participation of wild birds in the introduction of various pathogens into the regions of Kazakhstan requires further study.

Bats carry thousands of viruses from 28 different families. To determine the presence of various pathogens in bat populations in Kazakhstan, 1149 samples (393 oropharyngeal swabs, 349 brain samples, 407 guano) were collected. The samples were collected from four species of bats (Vespertilio murinus, Nyctalus noctula, Myotis blythii, Eptesicus serotinus) in nine regions. The Coronavirus RNA was found in 38 (4.75%) samples, and the rabies virus in 27 (7.74%) samples from bats. Coronaviruses and the rabies virus were found in bats in six out of nine studied areas. The RNAs of SARS-CoV-2, MERS, TBE, CCHF, WNF, influenza A viruses were not detected in the bat samples. The phylogeny of the RdRp gene of 12 samples made it possible to classify them as alphacoronaviruses and divide them into two groups. The main group (n = 11) was closely related to bat coronaviruses from Ghana, Zimbabwe and Kenya. The second group (n = 1) was closely related to viruses previously isolated in the south of Kazakhstan. The phylogeny of the N gene sequence from a bat from west Kazakhstan revealed its close relationship with isolates from the Cosmopolitan group of rabies viruses (Central Asia). These results highlight the need for a continuous monitoring of volatile populations to improve the surveillance and detection of infectious diseases.

Avian influenza caused by influenza A viruses poses a serious threat to industrial poultry farming and human health due to the ability of some virus subtypes to cross the species barrier. According to production data, in 2020, 98 cases of outbreaks of influenza A/H5N8 among birds were registered in the Republic of Kazakhstan. As a result of the analysis, the isolated A/H5N8 viruses at the PLREKRRKR/G gradual change sites were derived from highly pathogenic avian influenza virus (HPAI). Phylogenetic analysis of the isolated isolates based on hemagglutinin allows them to be classified as clade 2.3.4.4b of the Eurasian Lineage II (Eurasian HPAIV H5N8 Lineage II). The homology level of Kazakhstani influenza A virus strains with strains isolated in China in 2020–2021 was 98.42–98.70%.

The causative agents of viral diseases among birds are widespread in nature. The spread of Newcastle among wild and domestic bird populations requires veterinary services to take effective control measures based on molecular epidemiological data.The article presents data from monitoring studies on Newcastle disease in various regions of Kazakhstan. Collection of samples from poultry and wild birds was carried out in private farmsteads in different regions of Kazakhstan.In order to determine the immune status of birds in individual farms and poultry farms, we conducted studies on the presence of antibodies to the Newcastle disease virus in the blood of birds.It has been established that 82.3% of birds from private farms and poultry farms have antibodies to the Newcastle disease virus in the blood sera. In Kostanay, Akmola, Turkestan and North Kazakhstan regions, the percentage of immune birds is above 80%, in Zhambyl, Kyzylorda, West Kazakhstan, Almaty and Abay the percentage of immune birds is within 55-72.1%.In Aktobe and Atyrau regions, 1-32% of birds have antibodies to the ND virus. It is likely that in these areas birds are not vaccinated across the entire population. The risk of developing ND is average.

According to the International Bureau of Epizootics, until recently, the territory of Kazakhstan was considered a free zone from foot-and-mouth disease in animals with vaccination, but there is a risk of the disease virus being introduced from cross-border countries into our republic. Therefore, the veterinary service and scientific community of our state need to conduct constant monitoring with seromonitoring and screening of the immune status of animals throughout the country.It is known that outbreaks of foot and mouth disease cause significant damage to livestock production and the economy of the Republic of Kazakhstan when the virus is likely to be introduced from disadvantaged countries led to the emergence of multiple foci of infection in the country and huge costs for their elimination.The introduction of foot-and-mouth disease into the regions of Kazakhstan that are part of the zone free from foot-and-mouth disease without vaccination, officially recognized by the World Organization for Animal Health, led to the suspension of the status of the entire zone, which in turn led to restrictions on both the export of livestock products and grain, and on trade inside the countryThe purpose of our study is to determine the seroprevalence of foot and mouth disease in Kazakhstan for 2021-2023.It has been established that there is still a high risk of introducing new genotypes of the foot-and-mouth disease virus into the territory of our country.