Searching the B. pertussis (Real Time PCR) in Cases with Prolonged Cough (andgt;2 weeks) in Population with Unvaccinated Adult: A Cross Sectional Study. Tehran, Iran

Aims: searching the B. pertussis-DNAs by Real time PCR in nasopharyngeal samples of cases with prolonged cough (>2 weeks) in population with unvaccinated adult. Study design: A cross sectional/analytic study done in Rasoul Akram hospital (May 2007-March 2009); Tehran, Iran. Methodology: According to WHO criteria; 170 cases with cough (>2 weeks) with either paroxysm of cough, inspiratory whoop, or post-tussive vomiting and other cases with cough (in contact with the index case) selected for study. B.pertussis searched in nasopharyngeal samples by conventional and Real time- PCR. Results: Out of 170 studied cases (mean age 27.3 years). 34.3% had previous contact with other cases with prolonged cough. 50% was febrile. 67.6% presented with WHO criteria and 32.4% had not any other symptom except prolonged cough. Abnormal chest x-ray reported in 61.6%. Positive B.pertussis -DNAs detected in samples by conventional -PCR and Real time-PCR was 20% and 2.4% respectively. 2 cases with positive Real time-PCR were <6 month and 2 adults in contact with chronic cough children. Conclusion: Whooping cough caused by the bacteria B. pertussis and B.parapertussis. High false positive (20% and 2.4%) results by conventional PCR usually indicated to nasopharyngeal carriage state not B.pertussis disease so It is preferred to use Real time- PCR for definite diagnosis of B. pertussis in suspected cases. For disease prevention in adolescents and control the circulation of the organism, booster vaccination (with acellular pertussis vaccines) in older children, adolescents, and adults are needed