CLINICAL FINDINGS IN BORDETELLA-PERTUSSIS INFECTIONS - RESULTS OF A PROSPECTIVE MULTICENTER SURVEILLANCE STUDY

Objective. To study the clinical presentation of culture-confirmed per tussis in children and their contacts with cough illnesses in an outpa tient setting. Methodology. In conjunction with a large pertussis vacc ine efficacy trial in Germany, a central laboratory to isolate Bordete lla species from nasopharyngeal specimens was established in Erlangen in October 1990. Pediatricians in private practices in southern German y, the Saar region, and Berlin were encouraged to obtain nasopharyngea l specimens and clinical characteristics from patients with cough illn esses 7 days' duration. Bordetella species were isolated by use of cal cium alginate swabs, Regan-Lowe agar, and modified Stainer-Scholte bro th. Clinical characteristics were determined by initial and follow-up questionnaires. Results. From October 1990 to September 1996, 20 972 s pecimens were submitted, and B pertussis was isolated in 2592 instance s (12.4%). Of the culture-proven cases, 50.7% were female, and the age range was 6 days to 41 years, with a mean and median of 4.3 years and 4.1 years, respectively. The following characteristics were noted. On ly 4% of the patients had received pertussis vaccine. Of unvaccinated patients, 90.2% had paroxysmal cough, 78.9% demonstrated whooping, and 53.3% presented with posttussive vomiting; 5.7% had fever 38 degrees C. The duration of cough was 4 weeks in 37.9% and 3 weeks in 17.4%. Le ukocytosis and lymphocytosis (values above the age-specific mean) were observed in 71.9% and 75.9% of unvaccinated patients, respectively. T he overall complication rate was 5.8%, and pneumonia (29%) was the mos t frequent complication. In infants < 6 months of age, the rate of com plications was 23.8%. One death in a 7-month-old infant occurred. Conc lusions. Typical symptoms of pertussis were observed in the great majo rity of patients regardless of age group. However, the duration of cou gh was surprisingly short in one sixth of the patients. These short il lness cases would not be classified as pertussis according to the Worl d Health Organization clinical case definition, which requires 21 days of spasmodic cough.