Clinical characteristics of pertussis and no-pertussis in children and adolescents with chronic cough

Objective To compare the clinical manifestations and complications of pertussis and no-pertussis in children and adolescents with chronic cough.Methods Subjects aged above 6 years old with chronic cough for more than 2 weeks had been recruited in Shanghai,Chongqing,Kunming,and Yinchuan.Subjects were divided into pertussis and no-pertussis groups according to laboratory test.The laboratory test for identification of B.pertussis included culture,multiplex PCR,and specific toxin antibody of B.pertussis(PTIgG) assay by ELISA.Results A total number of 1 001 subjects were enrolled.Among them,113 subjects were pertussis positive,and 888 subjects were pertussis negative.The positive rate was 11.3%.In pertussis positive group,40.7% subjects had intermittent paroxysmal cough,but no subjects had roaring,vomiting,cyanosis,and apnea.18.6% pertussis positive subjects were complicated with pneumonia.Compared with the pertussis positive group,no-pertussis subjects had a significantly lower rate of intermittent paroxysmal cough(29.7%)(P 0.01).Conclusions Paroxysmal cough is the predominant clinical manifestation in older children and adolescents with pertussis,but the typical complications of pertussis are rare.Diagnosis of pertussis by clinical manifestations may lead to a missed diagnosis and delay proper treatment.