Analysis of etiology and clinical manifestations of 90 patients with suspected pertussis under 2 years old / 中华传染病杂志

ABSTRACT

Objective To investigate the etiology and clinical manifestations of patients with suspected pertussis under 2 years old.Methods A total of 90 patients under 2 years old with suspected pertussis were collected prospectively from July 2015 to June 2016.Nasopharyngeal secretions and clinical data were obtained.Bordetella pertussis was detected by polymerase chain reaction (PCR).Patients were classified into pertussis group if the PCR was positive,or pertussis syndrome group if negative.Other 13 respiratory viruses and atypical pathogens were also detected,and bacterial culture was performed.Pathogens and clinical manifestations were compared between groups.For normal distributed data,continuous variables between groups were compared using two-sample t-test,while categorical variables between groups were compared using chi-square test.Results A total of 90 suspected cases were included,including 46 males and 44 females.Age ranged from 33 days to 18 months,and the median age was 3 months.Thirty-five cases (38.9％) were positive for Bordetella pertussis PCR (the pertussis group),the age ranged from 34 days to 13 months,the median age was 2 months.Fifty-five cases (61.1 ％) were negative (the pertussis syndrome group),with the age ranging from 33 days to 18 months,and the median age was 4 months.In pertussis group,there was a higher percentage of hospitalization history in 1 month before onset than that of the pertussis syndrome group,and the difference was statistically significant (x2=4.496,P＜0.05).Patients in pertussis group were more likely to have cyanosis and cough at night (x2=4.234 and 10.960,both P＜0.05),and the course of pertussis was longer than that in pertussis syndrome (t=3.402,P＜0.05).The length of hospital stay before pertussis onset in pertussis group was longer than that in the pertussis syndrome group (P＜0.05).The mean white blood count in pertussis group was (22.00±9.42) × 109/L,and that in pertussis syndrome group was (16.31±8.10) × 109/L,and the difference between the two groups was statistically significant (t=3.049,P＜0.05).In pertussis group and pertussis syndrome group,influenza virus A was detected in 22 and 44 cases,respectively;rhinovirus in 16 and 25 cases,respectively;parainfluenza virus in 5 and 12 cases,respectively;respiratory syncytial viruses in 3 and 6 cases,respectively.Conclusions Patient who presents with cyanosis,cough at night and high white blood cell count is more likely to have pertussis.Influenza viruses A,humanrhinovirus and human parainfluenza viruses are common pathogens to be found in patients with suspected pertussis under 2 years of age.