Sentinel surveillance quality of influenza and influencing factors for influenza virus nucleic acid detection in Jingzhou, Hubei

ObjectiveTo evaluate the surveillance quality of influenza and influencing factors for influenza virus nucleic acid detection in two influenza sentinel hospitals in Jingzhou of Hubei province, and provide evidence for the improvement of the quality of influenza surveillance.

MethodsThe surveillance data of influenza-like illness (ILI) and pathogens from two influenza sentinel hospitals (hospital A and hospital B) in Jingzhou from 2010 to 2018 were collected from the China Influenza Surveillance Information System, ILI case proportion (ILI rate) and nucleic acid positive rate of ILI cases were used to evaluate the surveillance quality. Factors such as hospital, case sex, season, interval between onset and sampling, interval between sampling and detection were used as independent variables. Pathogen test result of ILI case was used as dependent variables, and the influencing factors was analyzed by two-category Logistic regression.

ResultsThe ILI rates of hospital A and hospital B were 2.34% and 1.34%, respectively, and the difference was significant (χ²＝3 096.26, P＝0.000). The influenza virus nucleic acid positive rates of hospital A and hospital B were 13.63% and 14.84%, respectively, and the difference was significant (χ²＝4.69, P＝0.030). The change trends of ILI rate and nucleic acid positive rate of the two sentinel hospitals were consistent (r_s＝0.568, P=0.000; r_s＝0.824, P＝0.000). Hospital A and Hospital B had consistent change trends of ILI rate and nucleic acid positive rate (r_s＝0.306, P＝0.026; r_s＝0.477, P＝0.000). Logistic regression results showed that sentinel hospital (OR＝1.15, 95% CI: 1.05–1.26) and season (OR＝3.19, 95% CI: 2.88–3.52) were associated with the positive rate of influenza virus nucleic acid detection.

ConclusionThe overall performance of influenza sentinel surveillance was well in Jingzhou. There were differences in ILI rate and positive rate of influenza virus nucleic acid detection between two influenza sentinel hospitals. Sentinel hospital and season were the main factors affecting the positive rate of influenza virus nucleic acid detection.