Detection of occult hepatitis B virus infection among blood donors in Sudan

Genetic diversity and occult hepatitis B infection in Africa: A comprehensive review

BACKGROUND

Occult hepatitis B infection (OBI) is a globally prevalent infection, with its frequency being influenced by the prevalence of hepatitis B virus (HBV) infection in a particular geographic region, including Africa. OBI can be transmitted through blood transfusions and organ transplants and has been linked to the development of hepatocellular carcinoma (HCC). The associated HBV genotype influences the infection.

AIM

To highlight the genetic diversity and prevalence of OBI in Africa.

METHODS

This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and involved a comprehensive search on PubMed, Google Scholar, Science Direct, and African Journals Online for published studies on the prevalence and genetic diversity of OBI in Africa.

RESULTS

The synthesis included 83 articles, revealing that the prevalence of OBI varied between countries and population groups, with the highest prevalence being 90.9% in patients with hepatitis C virus infection and 38% in blood donors, indicating an increased risk of HBV transmission through blood transfusions. Cases of OBI reactivation have been reported following chemotherapy. Genotype D is the predominant, followed by genotypes A and E.

CONCLUSION

This review highlights the prevalence of OBI in Africa, which varies across countries and population groups. The study also demonstrates that genotype D is the most prevalent.

Transfusion Transmissible Infections in Blood Donors in the Province of Bié, Angola, during a 15-Year Follow-Up, Imply the Need for Pathogen Reduction Technologies

Transfusion transmissible infections (TTIs), caused by hepatitis B virus (HBV), human immunode-ficiency virus (HIV), hepatitis C virus (HCV), and syphilis, have a high global impact, especially in sub-Saharan Africa. We evaluated the trend of these infections over time in blood donors in Angola. A retrospective cross-sectional study was conducted among blood donors in Angola from 2005 to 2020. Additionally, frozen samples obtained from blood donors in 2007 were investigated to identify chronic HCV carriers and possible occult HBV infection (OBI). The overall prevalence of HBV, HCV, HIV, and syphilis was 8.5, 3, 2.1, and 4.4%, respectively, among 57,979 blood donors. HBV was predominant among male donors, while the remaining TTIs were predominant among women. Donors >50 years had a significantly high prevalence for all TTIs. Chronic HCV infection was ab-sent in 500 samples tested and OBI was present in 3%. Our results show the continued high prev-alence of TTIs among blood donors in Angola. Most infections showed a significantly low preva-lence in years with campaigns seeking voluntary blood donors, thus, reinforcing the importance of this type of donor to ensure safe blood. Africa, with a high prevalence of diverse pathogens, should consider cost-effective pathogen reduction technologies, once they are commercially accessible, to increase the availability of safe blood.

Occult hepatitis B virus infection in Sudan: A systematic review and meta-analysis

In its occult form, hepatitis B virus infection can only be detected using molecular techniques such as polymerase chain reaction, increasing the cost of the screening process. Certain population subgroups are considered to have a higher risk of transmission and reactivation of occult hepatitis B virus infection (OBI). This review aims to estimate the prevalence of OBI among these high‐risk groups in Sudan. It was conducted under the PRISMA guidelines, targeting the literature available in MEDLINE/PubMed, ScienceDirect, Google Scholar, and Cochrane Library databases. Full‐text articles published in the last 10 years that provide prevalence estimates of OBI in Sudan were examined for fulfillment of eligibility criteria. Quality assessment of selected articles was performed using the critical appraisal tool reported by Munn et al. Publication bias was assessed by visual examination of the funnel plot. Meta‐analysis using the random‐effects model with 95% confidence interval was used to calculate the overall and subgroup pooled prevalence of OBI. Literature search yielded a total of 717 studies, of which only 11 articles fulfilled all selection criteria. The overall pooled prevalence of OBI was found to be 15.51%, with a high level of heterogeneity. Subgroup analysis demonstrated a prevalence of 16.48% among blood donors, 13.36% among hemodialysis patients, and 12.59% among febrile patients. Evidence for possible publication bias was detected. This review provides crucial evidence for health authorities in Sudan, outlining the necessity for re‐evaluation of the current screening strategies, especially among these high‐risk groups.

Molecular Detection of Occult Hepatitis B virus in plasma and urine of renal transplant patients in Khartoum state Sudan

OBJECTIVE

The aim of this study was to determine the OBI in plasma and urine samples from renal transplant patients using Multiplex Nested PCR.

METHOD

A total of 100 samples (plasma and urine) were collected from renal transplant patients admitted to the renal transplant center in Khartoum north, Sudan in 2019. For each sample, HBsAg, HBeAg and anti HBcAg were detected using Enzyme linked Immune sorbent assay (ELISA). The viral DNA was then extracted using viral DNA extraction kit and were then tested for HBV DNA by using multiplex nested PCR. Statistical analysis was done using statistical package of social science (IBM SPSS version 20.0) considering a P value ≤ 0.05 as a level of significance.

RESULTS

HBsAg were not detected in al patient but, HBeAg were 14 (14%) and anti HBcAg were 36 (36%)were detect by using ELISA. A total 18 (18%) and 3 out of 100 were found positive in plasma and urine samples, respectively. Regarding the virus genotypes, D, E and mixed D/E genotypes were detected in all positive samples. Females were significantly (P value=0.013) higher detectable with HBV than males in plasma samples CONCLUSION: OBI incidence in renal transplant patients is high in Sudan. The multiplex nested PCR had identified OBI with a high rate supporting the efficiency of using molecular techniques in detecting of HBV. This will lead to an appropriate diagnosis and minimizing the risk to be infected by HBV.

Characterization of occult hepatitis B in high-risk populations in Kenya

Occult hepatitis B infection (OBI) is defined as the presence of hepatitis B virus (HBV) DNA in the liver or serum in the absence of detectable HBV surface antigen (HBsAg). OBI poses a risk for the development of cirrhosis and hepatocellular carcinoma. The prevalence of OBI in Kenya is unknown, thus a study was undertaken to determine the prevalence and molecular characterization of OBI in Kenyan populations at high risk of HBV infection. Sera from two Nairobi cohorts, 99 male sex workers, primarily having sex with men (MSM-SW), and 13 non-MSM men having HIV-positive partners, as well as 65 HBsAg-negative patients presenting with jaundice at Kenyan medical facilities, were tested for HBV serological markers, including HBV DNA by real-time PCR. Positive DNA samples were sequenced and MSM-SW patients were further tested for hepatitis C virus (HCV) infection. Of the 166 HBsAg-negative samples tested, 31 (18.7%; 95% confidence interval [CI] 13.5–25.3) were HBV DNA positive (i.e., occult), the majority (20/31; 64.5%) of which were HBV core protein antibody positive. HCV infection was not observed in the MSM-SW participants, although the prevalence of HBsAg positivity was 10.1% (10/99; 95% CI 5.6–17.6). HBV genotype A was predominant among study cases, including both HBsAg-positive and OBI participants, although the data suggests a non-African network transmission source among MSM-SW. The high prevalence of HBV infection among MSM-SW in Kenya suggests that screening programmes be instituted among high-risk cohorts to facilitate preventative measures, such as vaccination, and establish entry to treatment and linkage to care.

Significance of HBV NAT Among HBs Antigen-Negative Blood Donors in Saudi Arabia

Background

Bloodborne hepatitis B virus (HBV) transmission from asymptomatic donors with acute HBV infections who have undetectable surface antigen of HBV (HBsAg), or from donors with chronic infections in whom serological markers were not detected, could cause residual infections leading to relevant transfusion-transmitted infections (RTTIs). HBV nucleic acid testing (NAT) can detect HBV DNA in the HBsAg-negative and total hepatitis B core antibody (anti-HBc)-negative window period of infection and in chronic cases.

Objective

To assess the presence or absence of HBV DNA in blood donors with HBsAg negativity.

Methods

We collected 3014 blood specimens from volunteer blood donors at the blood bank of King Khalid University Hospital in Riyadh, Saudia Arabia. Specimens from each donor were tested for HBsAg, anti-HBc, and hepatitis B surface antibody (anti-HBs) by commercial immunoassays and for qualitative assessments of HBV-DNA by HBV-NAT testing.

Results

Of the 3014 donors, 7 (0.23%) tested positive for HBsAg and anti-HBc, 1 for HBsAg (0.03%) only, and of those 264 donors (8.8%) for anti-HBc. Of these last, 6.9% also tested positive for anti-HBs and 1.9% tested negative for anti-HBs. HBV-NAT testing was reactive in 75.0% of subjects who tested HBsAg positive, and nonreactive in 100% of subjects who tested anti-HBc positive/HBsAg negative (with or without anti-HBs). Among 2742 donors who tested seronegative, 1 specimen was determined to be reactive via HBV-NAT testing.

Conclusions

The frequency of HBV DNA in blood donors who tested seronegative was low. This finding may indicate the significance of the HBV NAT technique in reducing the residual risk of transfusion-transmitted HBV infection.

Prevalence of Hepatitis B Virus (HBV) Among Blood Donors in Eastern Saudi Arabia: Results From a Five-Year Retrospective Study of HBV Seromarkers

Background

Transfusion-transmissible hepatitis B virus (HBV) infection is a major problem worldwide. Recently, confirmatory nucleic acid tests (NATs) for HBV DNA have been employed in several countries. We assessed the prevalence and yearly trends of HBV infection in blood donors in the Eastern Province of Saudi Arabia, screening for HBV surface antigen (HBsAg), antibody against HBV core antigen (anti-HBc), and HBV DNA.

Methods

Between 2011 and 2015, a total of 22,842 donors were screenedfor HBsAg, anti-HBc, and HBV DNA using the HBsAg Qualitative II kit (Abbott, Ireland Diagnostics Division, Sligo, Ireland), ARCHITECT Anti-hepatitis B core antigen antibody (HBc) II Assay kit (Abbott GmbH & Co. KG, Wiesbaden, Germany), and NAT Procleix Ultrio Elite Assay kit (Grifols Diagnostic Solutions Inc., Los Angeles, CA, USA), respectively.

Results

A total of 739 (3.24%) donors were HbsAg(+), anti-HBc(+), or HBV DNA(+); 63 (0.28%) were HbsAg(+), anti-HBc(+), and HBV DNA(+). Twelve (0.05%) were anti-HBc(+) and HBV DNA(+) but HBsAg(−); they were considered to have occult infection. Further, 664 (2.91%) were HBsAg(−) but anti-HBc(+), indicating chronic or resolving infection. HBV prevalence increased significantly from 2011 to 2012, increased marginally till 2013, and showed a decreasing trend from 2013 (P>0.05).

Conclusions

The five-year prevalence of HBV infection among blood donors in the Eastern Province of Saudi Arabia (3.24%) is lower than that reported for other regions in the country. The occult HBV infection rate of 0.05% emphasizes the importance of NATs in isolating potential infectious blood units.

Systematic review and meta-analysis of HIV, HBV and HCV infection prevalence in Sudan

Viral hepatitis constitutes a global health problem; previous studies have affirmed a considerable morbidity and mortality from both acute infections and chronic complications. On the other hand, Human Immunodeficiency Virus (HIV) infection is also of known burden. Determining prevalence measures of these viruses is crucial for establishing appropriate country specific strategies regarding prevention, diagnosis, and containment. This systematic review was aimed to provide pooled seroprevalence estimates of the three viruses in Sudan. Structured review of the literature was conducted to obtain relevant studies published in both national and international databases. After assessment of quality and bias in all proposed studies, 57 prevalence studies were included. Meta-analysis was conducted for all studies and subgroup analysis was also approached. The total sample size of participants in included studies providing HIV antibodies prevalence was 15,479. Based on information retrieved from these studies, HIV prevalence ranged from 0 to 18.3% among different study populations. However, pooled prevalence estimate for HIV antibodies was 1%. Kassala, Eastern Sudan was the most endemic State (4.18%). The HBV reported seroprevalence rates ranged from 5.1 up to 26.81% among different populations and the overall pooled prevalence was 12.07%. For HCV antibodies; 2.74% was determined to be the pooled prevalence. Khartoum State was the most endemic State of both HBV and HCV with seroprevalence of 12.69% and 6.78%, respectively.Based on data reviewed and synthesized; there is no evidence for an HIV endemic in the general population of Sudan. However, both HBV and HCV seroprevalence rates are indicating otherwise. Reducing the overall burden of HIV, HBV and HCV infections will require new measures and national strategies and the recognition of the infections as one of the country's priority issues.

Prevalence of antibody to Hepatitis B core antigen and Hepatitis B virus DNA in HBsAg negative healthy blood donors

Background

Hepatitis B virus is one of the most important blood born viruses. Although the sensitivity of screening tests has been considerably increased, transmission may still occur due to window period or occult hepatitis B infections (OBIs). This study was aimed at evaluating the prevalence of the anti-HBc and identifying the HBV DNA in HBsAg negative blood donors.

Methods

The Blood samples from 2031 HBsAg-negative blood donors were divided into three aliquots and tested for anti-HBc, anti-HBs and HBV DNA. Serologic screening including anti-HBc and anti-HBs was performed. As a confirmatory test, all positive results for anti-HBc were retested with another kit. Two positive results were considered for anti-HBc positivity. All HBsAg negative selected donations were tested by PCR assay on pooled specimens (five samples per pool), plasma samples found to be HBsAg negative but anti-HBc positive were selected for a single-unit specimen Real-Time assay.

Results

The study population had a mean age of 33.25 ± 10.09 years were mainly composed of males (94.8 %). The seroprevalance rate was 4.9 % for Anti-HBc and 31.9 % for HBsAb. The majority (58.6 %) of Anti-HBc positive cases were regular blood donors with 42–49 years being the largest age group (41.4 %). Neither individual NAT nor pooled NAT test detected any HBV DNA.

Conclusion

However, Screening of anti-HBc Ab is proposed as a method to identify previous contact with HBV, but there is controversy in literature data regarding the cost-benefit of exclusion of positive anti-HBc Ab in blood donors. Our data does not suggest HBc-Ab test as a screening tool in the study setting.