EPIDEMIOLOGICAL FEATURES OF THE SPREAD AND DIAGNOSIS OF INFLUENZA AND ACUTE RESPIRATORY VIRAL INFECTIONS IN VOLYN AND MYKOLAIV REGIONS (2020–2022)

Abstract

Topicality. Influenza and acute respiratory viral infections (ARVI) remain the predominant infectious diseases in Ukraine, accounting for up to 90 % of all infectious morbidity annually. Despite their prevalence and potentialfor severe complications, vaccination coverage remains critically low. Studying regional epidemiological characteristics,particularly in the contrasting climates of Volyn and Mykolaiv regions, provides insights into the influence of environmentaland socio-demographic factors on the dynamics of respiratory infections and aids in improving preventive strategies.The goal – to analyze the regional peculiarities of the spread and diagnosis of influenza and acute respiratory viral infections in Volyn and Mykolaiv regions in 2020–2022.Materials and Methods. An epidemiological analysis of official statistics from the Center for Public Health (CPH) on the incidence of influenza and ARVI in Ukraine, Volyn and Mykolaiv regions (2020–2022) was used. Intensity indicators, epidemic thresholds, age structure, hospitalization rates, and vaccination coverage were taken into account. A comparative analysis of laboratory monitoring data from the regional centers for disease control and prevention (RDCP) using PCR, ELISA, and ELISA to detect pathogens was conducted. Comparison of regional data allowed us to identify thepeculiarities of the epidemic process.Research results. In 2020–2022, influenza and ARVI remained the leading infectious pathology in Ukraine, accounting for up to 90% of infectious morbidity. Volyn region had higher rates of reported cases, while Mykolaiv region had a higher proportion of laboratory-confirmed cases. It was found that climatic conditions affect seasonality: epidemics start earlier in Volyn compared to Mykolaiv region. The COVID-19 pandemic and military events have led to a change in the structure of pathogens, an increase in the proportion of SARS-CoV-2, and in 2021–2022, the return of influenza A(H1N1)pdm09 and B. Diagnostics was based mainly on PCR, supplemented by ELISA and MFA in Mykolaiv. Vaccination coverage in both regionsremained critically low. The results emphasize the feasibility of a regionalized approach to surveillance and prevention.Conclusions. Influenza and ARVI remain the main infectious diseases in Ukraine, accounting for up to 90 % of cases each year. In 2020–2022, the incidence rate was consistently high. The COVID-19 pandemic has changed the seasonal dynamics: in 2020–2021, SARS-CoV-2 dominated, and in 2021–2022, influenza partially returned. More cases were registered in Volyn region, while Mykolaiv region had a higher percentage of laboratory-confirmed cases. The influence of climatic differences was identified: epidemics start earlier in Volyn and later in Mykolaiv, which should be taken into account when planning prevention. PCR remained the main diagnostic method, with ELISA and MFA used additionally in the south. The pathogens identified included SARS-CoV-2, influenza A(H1N1)pdm09, H3N2, and B/Victoria. Low vaccination rates require increased access to vaccinations and education. The study confirmed the effectiveness of aregionalized approach to controlling respiratory infections.