PCR ASSAY OR CULTURE FOR DIAGNOSIS OF BORDETELLA-PERTUSSIS IN THE ROUTINE DIAGNOSTIC LABORATORY

A nested PCR method was compared with culture for the detection of Bor detella pertussis in a routine clinical diagnostic laboratory, A total of 241 clinical nasopharyngeal aspirates were examined in parallel in the laboratory. Both methods were positive for 75 samples (31%)), eig ht samples were positive by nested PCR only (3.3%), and one sample was positive by culture only (0.4%), The mean time actually required in t he clinical laboratory (not operating with pertussis diagnosis during weekends) from the day of arrival to the diagnosis of a positive or ne gative sample by the nested PCR assay was 1.8 +/- 1.3 days (mean +/- S D), for positive culture 4.5 +/- 1.4 days and for negative culture 10. 5 +/- 1.0 days, The hands-on time in the laboratory to perform the nes ted PCR was 2 h, for a positive culture 25 min, and for a negative cul ture 15 min, The cost analysis of the methods, when running one sample at a time, showed that the laboratory cost for PCR was six times high er than culture, When running four samples together the cost for PCR w as three times higher than culture. In conclusion, the nested PCR is t he more rapid and sensitive method compared to culture, With the prese nt design, the PCR-protocol involves higher material expenditure and c laims more hands-on time.