Clinical analysis of children with pertussis and significance of respiratory virus detection in the combined diagnosis

Abstract

Objective: To analyze the clinical data of children with pertussis and explore the necessity of respiratory virus detection in the combined diagnosis so as to improve the clinician's understanding and standardize the diagnosis and treatment of pertussis in children. Method: Clinical data and laboratory examination of 195 suspected pertussis children between Jan. 2015 and Dec. 2016 in Children's Hospital Affiliated to Capital Institute of Pediatric were analyzed retrospectively. Result: The nasopharyngeal secretions were collected from 195 suspected pertussis children, PCR was employed to detect the nucleic acid of Bordetella pertussis. Meanwhile, 172 of 195 cases were screened for antigens of 7 common respiratory viruses by direct immunofluorescence (DIF) (respiratory syncytial virus(RSV), adenovirus(ADV), influenza virus A and B, parainfluenza viruses type Ⅰ-Ⅲ). (1) Eighty cases were positive in pertussis nucleic acid detection (positive rate was 41.0%), 47 males and 33 females, age ranged from one month to ten years, all of them had paroxysmal cough (100.0%), 50 cases with spasmodic cough (62.5%), 9 cases with vomiting after cough(11.2%), 22 cases with cyanosis after cough(27.5%), 13 cases with roaring after cough(16.2%), 4 cases with dyspnea(5.0%), 18 cases were diagnosed as pneumonia by chest radiography(22.5%) and 1 case was diagnosed as pertussis encephalopathy(1.2%); (2) 172 cases of respiratory virus DIF detection were completed and 69 of them were positive(positive rate was 40.1%), including 32 cases positive for RSV(18.6%), 29 cases for PIVⅢ(16.8%); (3) In 80 confirmed pertussis children, 66 cases of respiratory virus DIF detection were completed and 9 were positive(9/66, 13.6%), including 7 cases positive for PIVⅢ. The clinical manifestations were cyanosis after cough(6 cases), dyspnea(2 cases) and pneumonia were diagnosed by chest radiography in 3 cases, the clinical symptoms of these children were more prominent than children with general pertussis; (4) Patients were divided into three groups according to the pathogens: 57 cases in single pertussis group, 32 cases in RSV infection group, 22 cases in single PIVⅢ infection group.The cases of spasmodic cough in Pertussis group was 35 (61.4%), RSV infection group was 7(21.9%), single PIVⅢ infection group was 8(36.4%), compared with the other two groups, the incidence of spasmodic cough were higher in Pertussis group (χ(2) =12.850, 4.013, P<0.05). The cases of roaring in Pertussis group was 11 (19.3%), RSV infection group was 1(3.1%), single PIVⅢ infection group was 0, and the incidence were higher in Pertussis group (χ(2)=4.596, 4.932, P<0.05). The cases of dyspnea in Pertussis group was 2 (3.5%), RSV infection group was 11(34.4%), single PIVⅢ infection group was 0, and the incidence was higher in RSV infection group (χ(2)=15.654, 9.487, P<0.01). Conclusion: Pertussis is common in children, especially in unvaccinated or incompletely vaccinated infants. The typical clinical manifestation is paroxysmal spasmodic cough; complicated with PIVⅢ infection is a risk factor for sever pertussis. Early detecting of Bordetella by PCR is helpful for the diagnosis of pertussis, RSV and PIVⅢ are the main pathogen for Pertussis-like syndrome. The detection of respiratory virus is helpful for differential diagnosis and medication guidance.