Pertussis: an update on primary prevention and outbreak control.

Pertussis is a highly contagious respiratory disease. Infected adolescents and adults with mild illness are the source of potentially life-threatening illness in infants and young children. The incidence of pertussis has been rising steadily in recent years. Primary vaccination is 80 percent effective, but protection is transient. Pertussis can be difficult to diagnose because classic whooping cough is uncommon, disease manifestations are often atypical, and laboratory and radiologic aids are frequently nonspecific. Diagnosis is usually based on the clinical picture, but culture, direct fluorescent antibody tests and serology can be helpful. Antibiotic therapy can decrease the duration and severity of illness, and prevents secondary spread if started early. Effective management of pertussis outbreaks requires early diagnosis and treatment of cases, antibiotic prophylaxis of contacts and accelerated vaccination of susceptible infants and children. Acellular pertussis vaccine preparations have recently been recommended for the entire primary vaccination series.