The high prevalence of occult hepatitis B infections among the partners of chronically infected HBV blood donors emphasizes the potential residual risk to blood safety

Combined detection of hepatitis B virus surface antigen and hepatitis B virus DNA using a DNA sensor

Hepatitis B virus (HBV) infection is associated with the progression of liver disease. Occult HBV infection (OBI) is defined as the existence of detectable HBV DNA in HBV surface antigen negative individuals. However, HBV DNA is negative in serum while HBV surface antigen remains positive in incompletely cured chronic HBV infection. Hence, combined detection of HBV surface antigen and HBV DNA is essential for the accurate detection and rehabilitation of HBV infection. Therefore, a multiplex detection strategy based on branched DNA nanostructures was developed. The single-stranded segment of a branched DNA nanostructure (segments of S4 and S2) assembled by four single-stranded DNA was hybridized with the aptamer of HBV surface antigen and DNA hairpin to construct a DNA nanosensor, which can achieve high specificity identification and highly sensitive fluorescence responses to the targets. The detection limits of the developed nanosensor for HBV and HBV DNA are 50 pM and 5 nM, respectively. The combined detection of HBV surface antigen and HBV DNA provides a new insight for more thorough diagnostic evaluation of HBV infection and rehabilitation.

Analysis of hepatitis B Virus Test results among blood donors in Chongqing, China

BACKGROUND

Hepatitis B virus (HBV) infection is a major concern regarding blood safety in countries with a high HBV prevalence, such as China. We aimed to understand the prevalence of HBV infection among blood donors in Chongqing and provide an important basis for developing appropriate blood screening strategies.

METHODS

Dual enzyme-linked immunosorbent assays (ELISAs) for hepatitis B surface antigen (HBsAg) were conducted in parallel with nucleic acid testing (NAT) of donors. All HBsAg-reactive and/or HBV DNA-positive blood samples were tested for HBsAg and hepatitis B DNA levels.

RESULTS

A total of 117,927 blood donor samples were collected from the Chongqing Blood Center between April 2020 and November 2020. In total, 473 HBV-ineligible samples were retained for HBsAg and DNA confirmation. A total of 272 samples were confirmed to be HBsAg+, including 2 HBV DNA - and 270 HBV DNA + samples. A total of 201 donations were HBsAg-, including 72 HBV DNA - samples. The rate of HBV infection was 65.33% (309/473) in men, which was significantly higher than that in women (p < 0.001). The HBV failure rate was higher among the first-time donors (p < 0.05). Of the 182 NAT R/HBsAg N/N samples (Nucleic acid test reactivity/2 anti-HBsAg tests negative), 37.91% (69/182) were false positives. The proportion of hepatitis B infections in the 18 NAT R/HBsAg N/R (Nucleic acid test reactivity/1 anti-HBsAg tests negative) samples was 94.44% (17/18), of which 50% (9/18) were occult HBV infection. A total of 95.83% (69/72) of the false positives were from the NAT R/HBsAg N/N group, and 58.33% (42/72) were first-time donors.

CONCLUSION

Our data showed a strikingly high HBV infection rate among blood donors in Chongqing. Double ELISA and single NAT can effectively prevent HBV leakage and improve blood safety. First-time donors have a high rate of HBV transplant failure; therefore, donors should be retained and recruited from low-risk groups.

Prevalence and Residual Risk of HIV in Volunteer Blood Donors of Zhejiang Province, China, from 2018 to 2022

Background

Blood safety levels have been significantly improved since the implementation of nucleic acid amplification technology (NAT) testing for blood donors. However, there remains a residual risk of transfusion transmission infections. This study aimed to evaluate the prevalence of HIV and its residual risk transmission among volunteer blood donors of Zhejiang Province, China, for five years after NAT implementation.

Materials and Methods

All specimens and information were collected from voluntary unpaid donors at all blood services in Zhejiang Province, China, from January 2018 to December 2022. The HIV antibody or antigen and HIV RNA were detected using enzyme-linked immunosorbent assay and NAT, respectively. The HIV residual risk transmission was calculated using the incidence or window period model.

Results

A total of 3,375,678 voluntary blood donors were detected, revealing an HIV prevalence of 9.92/100000. The HIV prevalence of blood donors in 12 blood services in Zhejiang Province was 6.11, 6.98, 7.45, 8.21, 8.36, 8.94, 9.04, 9.66, 9.73, 10.22, 11.80, and 12.47 per 100000 donors, without statistically significant difference observed among the services (p > 0.05). The HIV prevalence of males (15.49/100000) was significantly higher compared to females (1.95/100000; p < 0.05). There was an insignificant difference in HIV prevalence among blood donors of all different age groups (p > 0.05), but the HIV prevalence in the 26-35 age group and 18-25 age group was significantly higher compared to the 36-45 age group (p < 0.05). The difference in HIV prevalence between first-time blood donors (13.65/100,000) and repeat blood donors (6.78/100,000) was statistically significant (p < 0.05). From 2018 to 2022, the HIV residual risk in blood transfusion transmission was 0.266/100000.

Conclusion

The prevalence of HIV among blood donors in Zhejiang Province, China, is associated with age, gender, and times of blood donation. The HIV residual risk in blood transfusion transmission remains low in the province, and increasing the rate of repeat blood donors is beneficial to improve blood safety.

Serological and Molecular Characterization of Occult HBV Infection in Blood Donors from South Italy

Despite good vaccine coverage and careful blood donor selection policies, hepatitis B virus (HBV) is still the most frequent viral infection among blood donors (BDs) in Italy, mostly in the occult form (OBI). We studied the virological features of OBI in BDs from South Italy by serology, molecular testing for HBV-DNA, and sequencing for HBV genotypes and mutations. One hundred and two samples from 95 BDs (22.1% first time, 87.9% regular, median age 57 years) positive for HBV-DNA and negative for HBsAg were retrospectively analyzed. HBV biomarkers were detected in 96.9% (anti-HBc in 44.2%, anti-HBc plus anti-HBs in 49.5%, anti-HBs alone in 3.2%). No risk factor was declared by 45.3% of donors. HBV-DNA levels were very low (median: 7 IU/mL). All samples harbored HBV genotype D and single or multiple mutations in the S gene were found in 28/36 sequences analyzed and in 75% of donors. Mutations were unrelated to gender, donor group or serological patterns. An HBsAg assay with enhanced sensitivity was positive in samples from seven donors (7.4%), two of which negative for HBV-DNA by real-time PCR. OBI still represents a risk for HBV transmission from blood donations; screening by highly sensitive serological and molecular assays is warranted.