Measles in the elimination period: the epidemic situation in Voronezh region

Vaccine-preventable diseases, one of which is measles, do not lose their importance and still remain a threat to public health. There is a deterioration in the epidemic situation regarding measles, both in the world and in the Russian Federation. The purpose of the study was to characterize the manifestations of the measles epidemic process in the Voronezh region for the period 1940–2023. The study of morbidity was carried out on the basis of data from Rosstat Form 2, 146 maps of the epidemiological investigation of a case of measles in the Voronezh region for the period 2011–2023 with the calculation of basic statistical indicators. The general availability of effective measles vaccination led to a decrease in the incidence, which by the beginning of the 21st century had become sporadic. However, from 2011 to 2023, there is an upward trend in incidence: rates increased from 0.27 cases (95 % CI 0.06–0.48) to 2.14 per 100 thousand population (95 % CI: 1.54–2,74); the risk group were children (average age 5.70 ± 0.24 years). From 2011 to 2015 imported cases predominated; since 2016 local cases predominated. For 2011–2023 146 cases (81 outbreaks) of measles were registered; among those who fell ill, the majority were not vaccinated against this infection or did not know about their vaccination status. Seroprotection level for the period 2011–2023 averaged 94.09±0.41 %; in certain years, there was an insufficient level of the immune layer in indicator groups of the population 16–17 years old and older. Thus, the pronounced activation of the measles epidemic process in the Voronezh region in recent years is due to a decrease in the immune layer.