The incidence of whooping cough in children in the astrakhan region: a retrospective study

Objective. To determine the dynamics of whooping cough incidence in children in the Astrakhan region (AR) for the period 2000–2023. Materials and methods. The sources of information were statistical data from the Center for Hygiene and Epidemiology on the incidence of whooping cough in the territory of AR for 2000–2023, a retrospective analysis of 40 medical histories of infants with a confirmed diagnosis of whooping cough hospitalized to the Regional Infectious Diseases Hospital named after A.M. Nichoga for the period 2020–2023 was carried out. Results. It was determined that the total number of infants diagnosed with whooping cough in the AR in the period 2000–2023 was 770 cases, 134 (17.4 %) of them with an average number of 22.3 ± 4.1 (2.9 %) cases per year were revealed in 2000–2005; 198 (25.7 %) – in 2006–2010, i.e. – 39.6 ± 4.8 (5.1 %) per year; 54 (7 %) – 13,5 ± 3,7 (1,7 %) in 2011–2014; 208 (27 %) – 41,6 ± 8,5 (5,4 %) in 2015–2019; 20 (2,6 %) – 6,7 ± 4,2 (0,87 %) per year in 2020–2022; and 156 (20.3 %) cases in 2023. It can be assumed that the increase in the incidence of whooping cough was accompanied by its decrease in subsequent years due to an increase of the immune layer in infants and collective immunity of other age groups. The low incidence of whooping cough in 2020–2022 could contribute to a decrease in collective immunity among the population of the region and, as a result, an increase in the incidence of the disease in children. The incidence rate of whooping cough in 2023 was 49.2 per 100,000 people, which is 1.4 times higher than the national rate. According to the results of the analysis of the clinical symptoms of whooping cough in infants, severe forms of the disease were found in 22 (55 %) of the 40 patients included in the study. Conclusions. Severe forms of whooping cough in infants were observed in 55 % of cases, complicated – in 40 %. The decrease in pertussis vaccination coverage for children and adults in contact with infants is one of the reasons for the decrease in collective immunity and the increase in the incidence in infants of the region.