INTRODUCTION: The advent of a novel pathogen, such as SARS-CoV-2, and the subsequent implementation of a range of non-pharmaceutical interventions have resulted in alterations in disease prevalence, particularly in cases transmitted through an airborne mechanism.
AIM: The aim of the present study was to analyze the changes in the incidence of influenza and acute respiratory infections (ARIs), varicella (chickenpox), and scarlet fever, which occurred as a result of the spread of COVID-19 in Bulgaria.
MATERIALS AND METHODS: Official sources of epidemiological information (NCIPD, NCPHA, etc.) and a set of normative documents for the introduced anti-epidemic measures (AEMs) were used. The analysis of the distribution of varicella and scarlet fever covered the 2012–2022 period, and that of influenza and SARS-CoV-2: 2019–2022.
RESULTS: The incidence of varicella in the pre-pandemic period (2012–2019) ranged from 379.11%ooo to 437.54%ooo, and the incidence trend was upward. The addition to the data model for the 2020–2022 period radically changed the trend line to a downward one, with an average rate of decline of 18.5%ooo, although in 2022, with the liberalization of AEMs, there was a rise (388.82%ooo), characteristic for the pre-pandemic period. The incidence of scarlet fever in the 2012–2022 period had a downward trend with an average value of 43.08%ooo and varied from 42.15%ooo in 2012 to 15.62%ooo in 2022, with the lowest indicator in 2021 (2.66%ooo). The most pronounced changes were observed in influenza infection, when no influenza epidemic was registered in 2021.
CONCLUSION: The imposed 16 types of AEMs, mainly until February 2022, modeled the epidemic process of the presented respiratory pathogens.
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