Application of bacterial culture, polymerase chain reaction and serum antibody detection in the diagnosis of pertussis in children / 中华实用儿科临床杂志

ABSTRACT

Objective:To evaluate the auxiliary diagnosis value of bacterial culture, polymerase chain reaction (PCR) and serum anti-pertussis toxin immunoglobulin G (AntiPT-IgG) level detection in suspected pertussis.Methods:A total of 110 suspected cases of pertussis treated in the Department of Pediatrics of Wuhu No.1 People′s Hospital from June 2018 to May 2019 were recruited for the study.The nasopharyngeal swabs of all cases were collected for Bordetella pertussis culture and specific nucleic acid PCR detection.Serum samples of 78 cases were collected for the detection of AntiPT-IgG level by enzyme linked immunosorbent assays.Results:The positive rates of bacterial culture group and PCR group were 21.8% and 30.0%, respectively, with no statistically significant difference ( χ2=1.198, P>0.05). The culture positive rate of cases with the duration of cough<2 weeks was 32.1%, which was signi-ficantly higher than that of cases with the duration of cough about 2-4 weeks (14.3%) or >4 weeks (9.1%) ( χ2=6.522, P<0.05). The PCR positive rate of cases with the duration of cough <2 weeks was 39.6%, which was also significantly higher than that of cases with the duration of cough about 2-4 weeks (25.7%) or > 4 weeks (13.6%) ( χ2=6.126, P<0.05). The mean value for serum AntiPT-IgG level of 78 cases was (75.727±78.454) IU/mL, the median AntiPT-IgG levels of cases with the duration of cough<2 weeks and about 2-4 weeks were 5.909 IU/mL and 20.948 IU/mL, respectively, and the positive rates were 14.7% and 38.1%, respectively.The AntiPT-IgG level of cases with the duration of cough> 4 weeks and that at convalescent stage were (79.281±68.254) IU/mL and (107.242±75.750) IU/mL, and the positive rates were 39.1% and 57.1%, respectively. Conclusions:In the vaccine era, the results of pathogenic and serological tests should be combined to assist the clinical diagnosis of pertussis.The positive rate of bacterial culture and specific nucleic acid pathogen detection in children with cough duration less than 2 weeks is high, and the serological diagnosis is more effective after the duration of cough is over 4 weeks.