Ongoing Threats for Older Europeans: Diphtheria, Pertussis and Tetanus
Diphtheria, tetanus and pertussis represent an ongoing health threat across the world, and long-term immune protection does not exist for these diseases. Tetanus is the only non-communicable vaccine-preventable disease (VPD). It occurs mainly in older patients, during the warmer months when outdoor activity is higher, and its current epidemiology in Europe may be explained by lack of vaccination or waning immunity. Despite the low number of cases, tetanus is severe with high mortality, and thus, maintaining high vaccination coverage is important. Diphtheria is a potentially acute disease caused by exotoxin-producing Corynebacterium diphtheriae. It is affected by waning immunity, although the majority of reported cases are in unvaccinated adults or those with unknown vaccination status. It is therefore important to maintain high coverage rates as immunisation is the only effective method of preventing this toxin-mediated disease. Particular attention should also be given to revaccination of healthcare and social workers due to waning immunity. Finally, pertussis continues to represent a major cause of death in infants worldwide despite high vaccination coverage, whereas the clinical presentation of pertussis in adolescents and adults can be mild and often goes unrecognised. Indeed, reported pertussis incidence has increased markedly in recent years in almost all European countries, despite sustained high vaccine coverage, again highlighting the effect of waning vaccine immunity. Outbreaks in areas of high vaccination coverage highlight that vaccination strategies may need to be revisited and that consideration should be given to adolescent and adult boosters.