Bordetella pertussis surveillance in England and Wales: 1995-7

Available data sources on disease due to Bordetella pertussis, including no tifications, hospital admissions, deaths, and an enhanced laboratory-based surveillance system commenced in January 1994, were reviewed for the period 1995-7. Pertussis notifications continued their approximately 3-year cycle although at historically reduced levels. A slight seasonal increase in lat e summer/early autumn existed over and above a relatively constant backgrou nd rate. Over time, the proportion of pertussis cases in younger, unvaccina ted children, and to a lesser extent, adolescents and young adults, is incr easing. There is a continuing significant and under-reported mortality asso ciated with pertussis in the very young age group. Disease due to serotype 1,2 is on the increase despite persistent high vaccination levels and this serotype causes more severe disease. The provision of preventative antibiot ics prior to disease onset reduced the severity of the disease but its use remains uncommon in England and Wales. While overall levels of pertussis no tifications have declined in recent times, vaccination efficacy wanes with increasing age, and pertussis remains a significant cause of mortality and severe morbidity in the very young. This could be. reduced by timely booste r vaccination and increased recognition of mild disease in older cases foll owed by early antibiotic therapy for the very young household contacts.