Pertussis in Poland in 2018-2019.

Abstract

INTRODUCTION Pertussis is an endemic, highly contagious disease that can be prevented through vaccination. In Poland, since the second half of the nineties, changes in the epidemiology of pertussis have been observed - an increase in the number of cases, despite the high level of vaccination of the population. The highest percentage of registered cases of pertussis concerned people aged 15 and over. The causes of the increased incidence of pertussis are a complex problem. Immunity after pertussis vaccination is unstable, disappears within 4-12 years, and the risk of the disease increases with time after the last dose of the vaccine. Due to the loss of protection against pertussis in adults, it is important to repeat immunization with dTpa every 10 years. OBJECTIVE The aim of the study was to assess the epidemiological situation of pertussis in Poland in 2018-2019 compared to the situation in previous years, with particular emphasis on the assessment of the vaccination status of children against pertussis. MATERIAL AND METHODS The assessment of the epidemiological situation of pertussis in Poland was performed on the basis of the results of the analysis of unit reports of pertussis registered in the NIPH-NIH through the SRWE system and data from the bulletins "Infectious diseases and poisonings in Poland" for 2018 and 2019 and the bulletins "Vaccinations in Poland" for 2018 and 2019. RESULTS In 2018, 1 548 were registered, and in 2019 - 1 629 cases of pertussis. The incidence was respectively: 4.0 and 4.2 per 100 000 population and was lower compared to the incidence in 2017 (8.0). The highest incidence of pertussis was in the age group 0-4 years (20.6 and 23.6 respectively), and high in children and adolescents aged 5-9 (10.9 and 11.5 respectively) and 10-14 years (respectively: 12.2 and 11.2 - per 100 000 population). About half of the cases concerned people over 15 years of age. In general, a higher incidence among women was observed than in men, as well as a higher incidence in cities than in rural areas. In 2018, among people with pertussis, 434 people (i.e. 28%) and in 2019 - 482 people (i.e. 29.6%) were hospitalized. In 2019, one fatal case of the disease was reported to the epidemiological surveillance system. SUMMARY AND CONCLUSIONS In Poland, in the years 2018-2019, there was a decrease in the number of cases of pertussis, the most common were children under the age of four (the highest incidence). A worrying trend is the decreasing number of vaccinations in children aged 2 years against pertussis covered by compulsory primary vaccinations in individual provinces. In the current epidemiological situation, the best way to prevent new cases of pertussis is to use vaccination according to the current regimen and to recommend to adults a single dose of dTpa vaccination, which should be repeated every 10 years.