Assessment of the duplicate notifiable reporting of hepatitis B infection in Zhejiang province, China, 2005-2015.

BACKGROUND

Hepatitis B virus (HBV) infection control has seen improvements since the introduction of the HBV vaccination program in China. However, the reported incidence rate of HBV infection remains high owing to the large pool of individuals infected before the start of the HBV immunization program. The duplicated reporting of HBV had a remarkable effect on the overestimation of HBV disease burden, according to the Chinese National Notifiable Diseases Report System (NNDRS).

METHODS

We analyzed the data of HBV in Zhejiang province, China, collected for the years 2005-2015 from the NNDRS. The duplicate reporting cases of HBV were captured according to the same identification number or the same name, sex and date of birth, or the same name, sex and resident town/street code. We assessed the magnitude of duplicated reporting of HBV and explored the possible factors contributing to duplicated reporting.

RESULTS

There were 20,078 redundant HBV cases reported from the NNDRS during 2005-2015, which accounted for 6.33% (19,272/305,654) of all patients owing to duplicate reporting in Zhejiang province, China. Some risk factors, including male sex, age ≥20years, chronic cases, residence in outside counties, and farming as an occupation (odds ratio [OR]=1.06; 95% confidence interval [CI]: 1.02-1.11) were positively associated with the risks on duplicate reporting.

CONCLUSIONS

Our results demonstrated that the duplicated reporting of HBV infection is common in Zhejiang, China, which has contributed to a higher HBV infection prevalence than its real value. Some characteristics might affect the probability of duplicate reporting, including sex, occupation, place of residence, HBV type, and hospital type. These findings indicated the strong need to improve the data collection, deletion of duplications, and HBV classification during HBV surveillance, in order to obtain an accurate estimate of HBV disease burden in China. We also suggest establishing a specialized system to achieve high-quality HBV infection surveillance effectively and practically.