Analysis of changes in pertussis incidence dynamics in Poland in 2010–2021

Background
Whooping cough caused by Bordetella pertussis was a major threat to infants under 1 year of age. The introduction of the pertussis vaccination reduced the morbidity. In recent years, there are more cases in adults than children.

Objectives
The aim of this work is to analyze the epidemiological situation of pertussis in Poland from 2010 to 2021, including: increase of cases of whooping cough in 2015–2016, vaccination calendar recommended in Poland, vaccination rate in children aged 3 and 8 years old, and other factors influencing pertussis epidemiology.

Material and methods
We analyzed data from the National Institute of Hygiene during the period from January 1, 2010, to December 31, 2021. Data was also collected from the annual bulletins ‘Infectious diseases and poisoning in Poland’ ‘Epidemiological review’ and ‘Vaccinations in Poland’ for the years 2010–2021, published by the National Institute of Hygiene and the Polish Society of Epidemiology and Infectious Diseases.

Conclusions
The study results identified multiple causes of increasing cases of pertussis in Poland between 2010 and 2021. These include: a significant correlation between decreasing vaccination rates and increased cases of whooping cough, periodic increase in adult pertussis linked to reduced post-vaccination immunoglobulin levels and delayed treatment due to atypical symptoms, as well as the immigration of people with uncertain vaccination status. We find promotion and popularization of vaccination as the most effective way to fight the rate of pertussis.