ABSTRACT
<p><b>OBJECTIVE</b>To understand the age distribution of pertussis patients admitted in the children hospital and to analyze the source of infection as well as its transmission patterns.</p><p><b>METHODS</b>Patients visiting to the Children Hospital and epidemiologically related cases during Feb. 2012 to Aug. 2013 were tested to confirm the diagnosis. Excel 2007 software was used to analyze the age distribution and clinical symptoms of clinic cases, the source of infection or subsequent cases.</p><p><b>RESULTS</b>165 out of 254 clinically suspicious pertussis cases and 38 out of the 54 epidemiologically related cases were confirmed of having pertussis infection. There were 138 (83.6%) cases under 1 year of age in the confirmed clinical cases and 36 (94.7%) cases older than 20 years of age among the confirmed epidemiologically related pertussis cases. All the confirmed epidemiologically related cases were misdiagnosed or missed for diagnosis. As the source of pertussis infection in confirmed clinical cases, parents played an imported role among 25 of the 32 cases. Transmission from infants and/or little children to adults were also observed in this study.</p><p><b>CONCLUSION</b>Infants accounted for the most among the pertussis patients that visiting the clinics. Adults, being misdiagnosed or missed diagnosed, were the main sources of infection to infants. Epidemics of pertussis occurred under family aggregation. Further study was in need to develop the proper strategy for pertussis booster vaccination.</p>