[Pertussis in year 2000].

Reemergence of pertussis in a form of epidemic was observed in Poland in 1997/1998. After some decrease of incidence in 1999, year 2000 brought another increase in pertussis morbidity (2,269 cases; incidence 5.9/100,000), most of them in the older age group of 10-14. It indicates rather sustained trend of increased incidence and shift in the age of infected. It may be due to decrease of immunity with age. According to the vaccination calendar in Poland, last pertussis vaccination is given before the age of two. More cases occurred among females (6.3/100,000) than among males (5.4/100,000) and in urban areas (7.8/100,000) than in the rural ones (2.8/100,000). Big differences in numbers of cases reported between different districts and between urban and rural populations bring strong possibility of insufficient sensitivity of the surveillance in many regions of Poland. It is concluded that increase of pertussis incidence in Poland, causes urgent need of additional vaccination in the age of 5 to secure protection for the older age groups.