EPIDEMIOLOGY OF PERTUSSIS IN THE YAROSLAVL REGION DURING PLANNED MASS IMMUNIZATION

Objective. To identify the regularities of the epidemic process of whooping cough during planned mass immunization for children in the Yaroslavl Region under the current sociodemographic conditions and to elaborate measures to reduce the incidence of this infection. Materials and methods. The authors performed a comparative retrospective epidemiological analysis of the incidence of pertussis, the demographic situation, and the quality of vaccination in the Yaroslavl Region, by using data from the state infectious diseases reports by the Directorate for the Yaroslavl Region, Russian Federal Service for Supervision of Consumer Rights Protection and Human Welfare, and those by the Russian Federal Service for Supervision of Consumer Rights Protection and Human Welfare, statistical observation forms No. 2 «Information on Infectious and Parasitic Diseases» and No. 6 «Information on Contingents of Children and Adults Vaccinated Against Infectious Disease» over 2004-2016. Results. Whatever the coverage and timeliness of immunization, whooping cough was shown to be characterized by common epidemiological patterns: long-term dynamics, periodic upsurges of morbidity rates, changes in the structure of morbidity, and pronounced territorial irregularity. It was established that the intensity of the epidemic process of pertussis and the features of its manifestations were largely determined by the demographic situation, the size of the pediatric population, social conditions, and the insufficient duration of postvaccination immunity. Thus, in 2016, the incidence of pertussis increased by 8.7% compared to 2015, amounting to 23.1 per 100,000 population, which was 4.1 times the average level in the Russian Federation (5.6 per 100,000 population). The highest morbidity rates were noted among infants under 1 year of age (206.5 per 100,000 babies of this age) and schoolchildren (167.8 per 100,000 children in this category). Conclusion. The features of the present-day epidemiology and clinical course of pertussis necessitate changing the vaccination tactics and introducing revaccination with acellular vaccines in children and adults. In order to protect newborns from whooping cough, it is advisable to promptly vaccinate all family members without a history of this infection, including adults. This will be able to protect a baby in the first 6 months of life before he/she develops postvaccination immunity.

pertussis, vaccination, morbidity, epidemic process, periodic upsurges, anti-epidemic measures, postvaccination immunity