Comparison of throat and nasopharyngeal swab specimens for culture diagnosis of Bordetella pertussis infection

Abstract

During a 9-month period, we evaluated the relative sensitivity of throat and nasopharyngeal swab cultures for isolation of Bordetela pertussis. Of 38 pertussis cases, 36 (95%) had positive nasopharyngeal cultures, while only 16 of 36 (44%) had positive throat cultures. There were no cases of nasopharyngeal-negative, throat-positive cultures. The sensitivity of the direct fluorescent-antibody test was 70% when compared with culture.

Comparison of nasopharyngeal aspirates with swabs for culture of Bordetella pertussis

“…The fact that repeated cultures in clinically suspected cases of pertussis increased the number of positive cultures by 25% also supports suspicions that sampling often is inappropriate (3). The collection procedure (1,7,10) and swab material (1, 6, 13) are factors that have a great impact on the recovery of Bordetella pertussis. Al-though it is regarded as less practical than nasopharyngeal swabbing, sampling by aspiration has been advocated by some authors (1,14).…”

Comparison of three kinds of blood and two incubation atmospheres for cultivation of Bordetella pertussis on charcoal agar

“…Bordetella pertussis has no C02 requirement (4), but some authors have used an atmosphere with 5 to 10% C02 for cultivation (1,3). To our knowledge, no study that compares the two incubation atmospheres with respect to charcoal agar has been published (2).…”

“…The manufacturer of charcoal agar base (Oxoid Ltd., Basingstoke, United Kingdom) recommends supplementing the agar with 10% whole defibrinated horse blood. Some authors have used sheep blood instead (1,3). Comparative studies of horse and sheep blood seem to be lacking.…”