Occult hepatitis B virus infection is a worldwide public health problem,which seriously affects the clinical diagnosis of hepatitis B and threatens the safety of blood transfusion.The concept of occult hepatitis B virus infection,the pathogenesis of occult hepatitis B virus infection,the prevalence of occult hepatitis B virus infection in different groups,including healthy population and different patients,and the possibility of transmission were summarized.The prevalence of occult hepatitis B virus infection was found in healthy population and different patients,and there is possibility of occult hepatitis B virus infection to be transmitted through blood transfusion.The paper provides a comprehensive introduction of the pathogenesis and prevalence of occult hepatitis B virus infection.More attention should be paid to occult hepatitis B virus infection.

Objective:To monitor nucleic acid contamination and evaluate the biosecurity risk in a temporary 2019-nCoV nucleic acid testing laboratory situated within designated infectious disease care facilities.Methods:Quantitative real-time PCR technology was used to detect nucleic acid contamination in samples collected from high-risk experimental activity areas and the surface of the laboratory staff′s personal protective equipment. Sampling was conducted every Monday from March 14 to May 16, 2022, both during and after disinfection procedures.Results:A total of 760 samples were collected from 40 sampling sites. A total of 27 out of 100 samples (27%) collected from 8 sampling sites in the sample processing area were positive. Among them, the contaminated area of biological safety cabinet, the outer surface of the sample transport box, and the sample rack were found to have the highest positive detection rates, with rates of 5/10, 4/10, and 6/10, respectively. Ten out of 140 samples (7.1%) obtained from 7 sampling sites in the nucleic acid detection area showed positive results. The inner wall of sample transfer window and the door handle of the nucleic acid detection area had the highest positive detection rates, both at 4/20. The Ct values for the target genes from the positive samples in the sample processing area were significantly higher than those from the nucleic acid detection area. The detection rate for nucleic acid contamination on the surface of the personal protective equipment of the laboratory staff was 20% (16/80), and the positive detection rate of the outer gloves from operator during the experiment reached 9/10. After disinfection, the nucleic acid residues on the surfaces of the various areas of the 2019-nCoV nucleic acid laboratory and the surfaces of the personal protective equipment of the laboratory staff were observed to be effectively removed.Conclusions:During experimental operation, the positive detection rate and nucleic acid contamination intensity of 2019-nCoV are higher in the sample processing area compared to those in the nucleic acid detection area. The laboratory staff are exposed to high biosecurity risk during the experiment. Implementing a scientific disinfection process can significantly reduce the risk of 2019-nCoV residues from the laboratory environment and the surface of the personal protective equipment of the laboratory staff, ensuring the accuracy of inspections and the safety of the laboratory staff.