Pertussis in Germany: regional differences in management and vaccination status of hospitalized cases

The incidence of pertussis requiring hospitalization in children younger th an 16 years was estimated by the use of an active surveillance-system. Of s pecial interest were differences between West and East Germany following di fferent vaccination strategies before reunification. In 1997 and 1998, 754 pertussis cases required a total of 11151 hospital inpatient days. The inci dence of hospitalized pertussis was 2.68/100 000 person years and this was significantly higher in East than in West Germany. In East Germany an unusu ally high percentage of hospitalized cases was found in children aged 6-15 years (45 % versus 13 % in West Germany). The difference between the region s may be due either to a different perception of the disease or to an incre ased immunity induced by prior disease or vaccination. In East Germany, per tussis was rare until reunification but it has increased significantly sinc e then. Older children may thus represent a population at risk of pertussis having not had previous exposure to pertussis antigens.