Application of bacterial culture and nucleic acid detection in the diagnosis of pertussis in children / 中华检验医学杂志

ABSTRACT

Objective:To analyze the clinical characteristics of pertussis cases diagnosed by two pathological detection methods: bacterial culture and real-time polymerase chain reaction (RT-PCR), and to explore the applicable value of two pathological detection methods in the diagnosis of pertussis.Methods:Bilateral nasopharyngeal swabs and clinical information of 165 children suspected of pertussis were collected by Hebei Children′s Hospital from April 2019 to January 2020. The bacterial culture and RT-PCR for nasopharyngeal swab specimens were performed in all cases. Chi-square test was used to analyze the cases of pertussis diagnosed by the above two methods.Results:Based on clinical diagnosis, the sensitivity of bacterial culture and RT-PCR for the diagnosis of pertussis was 61.70% (58/94) and 86.17% (81/94), and the specificity was 92.96% (66/71) and 71.83% (51/71), respectively. The positive rate of RT-PCR in children of all ages, seasons and cough courses is higher than that of bacterial culture. Children with pertussis diagnosed by bacterial culture and RT-PCR were basically similar in age, season, and cough course distribution, with the most common cases ≤3 months old, a high incidence trend in summer and autumn, and the course of coughing in children was mostly within 15-21days. The positive rate of bacterial culture in the diagnosis of pertussis in children is affected by the age of the children, and there are statistical differences between children in different age groups (χ2= 11.929, P=0.036). The positive rate of bacterial culture was the highest in children with >3 years old (51.85% [14/27]), followed by children with ≤3 months old (48.72% [19/39]), and the lowest in children with >6-12 months old (15.00% [3/20]). Moreover, the positive rate of bacterial culture in the diagnosis of pertussis in children is also affected by the cough course of the children, and there are statistical differences between children in different cough course groups (χ2=9.841, P=0.020). The positive rate of bacterial culture was the highest in children with cough course 15-21 days (49.23% [32/65]), followed by 43.59% (17/39) in children with cough course 8-14 days, and the lowest in children with cough course of less than 7 days (22.86% [8/35]). Conclusions:Compared with RT-PCR, bacterial culture has lower sensitivity and higher specificity in the detection of pertussis. These two detection methods have their own advantages and limitations. Medical institutions at all levels should comprehensively analyze different laboratory detection methods. Only by combining the two methods can the diagnostic value and level be effectively improved.