The detection rate of pertussis in children and infants with persistent cough in Beijing during 2011-2016

Objective To investigate the prevalence of pertussis in infants and children with persistent cough in Beijing during 2011-2016. Methods The eligible infants and children from over ten hospitals who were suspected to have pertussis from 2011 to 2016 were enrolled for detection. Nasopharyngeal secretions and blood samples were collected. Multiplex-PCR was performed for Bordetella pertussis and real-time PCR was performed for nucleic acid of Bordetella pertussis. Results A total of 1 318 eligible cases were enrolled, including 820 males and 498 females. Pertussis was detected positive in 534 cases, including 81.3% (434/534) of B. pertussis positive cases and 31.8% (170/534) of IgG positive cases. There were 13.1% (70/534) had double positive for bacteria and antibodies. From 2011 to 2016, the enrolled patients were increased from 103 cases per year to 460 cases per year, and the test positive patients were increased from 29 cases to 194 cases. Among the pertussis patients, 466 (87.3%) cases were younger than one year old. From the first quarter to the fourth quarter of the year, There were 65 cases, 151 cases, 205 cases, and 113 cases, respectively. In further analysis of the 268 cases from Children′s Hospital affiliated to Capital Institute of Pediatrics, 90.7% of the patients who had whooping cough were scattered children; 185 cases (69.0%) of the patients had not begun programmed immunization, 71 cases (26.5%) did not complete programmed immunization and 12 cases (4.5%) completed the programmed immunization. Of all the inpatients, 21.6% were critical ill, 0.8% (2 cases) dead, and the remaining patients were recovered and discharged. Conclusions The prevalence of pertussis is increasing, especially in summer. Infants are the most susceptible population. Bordetella pertussis is one of the most important pathogen that can induce persistent and chronic cough. Key words: Whooping cough; Epidemiology; Polymerase chain reaction