Difference between Nested-polymerase chain reaction and virus isolation in detection of respiratory syncytial virus and their clinical significances / 中华实用儿科临床杂志

ABSTRACT

Objective To observe the differences between Nested-polymerase chain reaction(N-PCR) and virus isolation methods used for detection of respiratory syncytial virus(RSV),and to reveal the potential clinical features of them.Methods From Jan.2010 to Aug.2012,nasopharyngeal aspirates (NPAs) were collected from the children with respiratory infection in the Department of Respiratory,the Children's Hospital of Chongqing Medical University.Both N-PCR and virus isolation were applied to detect RSV,and clinical data were collected for statistical analysis.Results A total of 1143 specimens were used for RSV detection by N-PCR and virus isolation.The male-female ratio was 2.16 vs 1.00.The age of patients was ranged from 1 month to 165 months(median7 months).The most common diagnoses were as followsbronchopneumonia [478 cases (41.8％)],chronic fibrous pneumonia [223 cases (19.5％)],bron-chiolitis [221 cases (19.3％)],bronchitis [71 cases (6.2％)] and upper respiratory infection [21 cases(1.8％)].For N-PCR,458 cases were RSV positive (total positive rate was 40.1％ ; 31.7％ for RSV-A,7.7％ for RSV-B,0.7％ for both RSV-A and RSV-B).With virus isolation method,204 cases were positive (17.8％).Comparison result of N-PCR and virus isolation showed165 cases were positive (P+ I+) and 646 cases were negative (P-I-) by both methods (identity was 70.1％),and the most difference was N-PCR positive but virus isolation negative group (P+ I-) (293 cases,25.6％).When compared to P-I-group,the clinical features of P+ I-group were as followsyounger,longer hospital stays,remarkable season distribution (with peak in winter and lowest in summer),lower percentage of fever,higher percentage of cough,wheezing,dyspnea,severe pneumonia and respiratory failure,all these differences were statistically significant(all P ＜ 0.05),the ma-nifestations matched the clinical features of RSV infection.When compared to P + I + group,the symptoms in the P + I-group had longer duration before they were admitted to hospital (P =0.005) and lower percentage of wheezing (P =0.009).Conclusions The differences between N-PCR and virus isolation for the detection of RSV existed in duration of symptoms prior to hospitalization.Both the sensibility and specificity of N-PCR are desirable for RSV detection.