Pertussis outbreak in Austin and Travis County, Texas, 1975

An outbreak of bacteriologically proven pertussis occurred in Austin and Travis County, Texas, over a 7-month period in 1975. Eighty persons were cultured for pertussis in our laboratory. A total of 62% of specimens from 34 individuals with suspected pertussis was positive for Bordetella pertussis. Diagnosis of acute cases by both culture and fluorescent antibody was attempted, and the correlation of the methods is given. Analyses of cases by age, sex, immunization status, and antibiotic treatment prior to culture are included in this report. Two asymptomatic, culture-positive adults were found.