RESUMEN
OBJECTIVES: To investigate the incidence, clinical characteristics and cost associated with pertussis in Thai children with persistent cough. METHODS: A prospective study was conducted among children aged 0-18 years with persistent cough for ≥7days with at least one of the following: paroxysm, inspiratory whooping, or post-tussive emesis. Nasopharyngeal swabs were obtained and tested for pertussis real time polymerase chain reaction (RT-PCR). RESULTS: 19.6% of children (28 out of 143) had pertussis confirmed by RT-PCR, 75% of cases occurred in children who were too young to complete their primary series of vaccine. Paroxysm and post-tussive emesis were the most consistent clinical features, identified in 96% and 93% of cases, respectively, whooping was found in only 18%. Pertussis cases were more likely to have household cough contact (64% versus 30%, p<0.001), be hospitalized (79% versus 58%, p=0.048) and experience protracted duration of cough (47 vs. 20 days, p<0.001) compare to their counterpart. CONCLUSION: Pertussis in Thai children is not infrequent and the common age group is young infant before completion of primary series of pertussis vaccine at six months of age, underline the importance of maternal pertussis immunization.