Occult Hepatitis B Virus Infection and Its Risks of Cryptic Transmission in Southern Ethiopia

Global prevalence of occult HBV infection in children and adolescents: A systematic review and meta-analysis

INTRODUCTION AND OBJECTIVES

Occult HBV infection (OBI) is a specific form of hepatitis B virus (HBV) infection and has the possibility of developing into hepatocellular carcinoma (HCC) in adults. This study aimed to estimate the global prevalence of occult HBV infection in children and adolescents.

MATERIALS AND METHODS

We systematically searched PubMed, Embase, Web of Science, and Cochrane databases for relevant studies on the prevalence of OBI in children and adolescents. Meta-analysis was performed using STATA 16 software.

RESULTS

Fifty studies were included. The overall prevalence of OBI in children and adolescents was 7.5% (95% CI: 0.050-0.103). In different risk populations, OBI prevalence was remarkably high in the HIV-infected population (24.2%, 95% CI: 0.000-0.788). The OBI prevalence was 0.8% (95% CI:0.000-0.029) in the healthy population, 3.8% (95% CI:0.012-0.074) in the general population, and 6.4% (95% CI: 0.021-0.124) in children born to HBsAg-positive mothers. Based on different serological profiles, the prevalence of OBI in HBsAg-negative and anti-HBc-positive patients was 6.6% (95% CI: 0.016-0.136), 3.0% (95% CI: 0.009-0.059) in HBsAg-negative and anti-HBc-negative patients, 4.6% (95% CI: 0.015-0.088) in HBsAg-negative and anti-HBs-positive patients, and 3.7% (95% CI: 0.001-0.102) in HBsAg-negative and anti-HBs-negative patients.

CONCLUSIONS

Despite HBV vaccination and hepatitis B immunoglobulin (HBIG), OBI is common in children and adolescents in high-risk groups.

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.

Frequency of viral infections in adolescent and adult in-patient Ethiopians with acute leukemia at presentation to a tertiary care teaching hospital: a cross-sectional study

BACKGROUND

Leukemic patients are prone to infectious agents such as viruses due to dysregulated immune system resulting from infiltration of the bone marrow by malignant cells, chronic stimulation, reactivation of some viruses and viral pathogenicity as well as rarely from acquisition of a new infections leading to severe complications. However, the prevalence of these infections has not been systematically documented in resource-limited settings such as Ethiopia.

OBJECTIVE

To determine the prevalence of HBV, HCV, and HIV among adult and adolescent in-patients with acute leukemia before the administration of chemotherapy, at the Tikur Anbessa Specialized Hospital (TASH) in Addis Ababa, Ethiopia.

METHODS

A cross sectional study was conducted on 176 adult and adolescent inpatient Ethiopians, who were diagnosed with acute leukemia from April 2019 to June 2021. Socio-demographic characteristics and relevant clinical data were collected. Peripheral blood samples were collected and tested for HBV, HIV, and HCV using Enzyme-Linked Immunosorbent Assay (ELISA) and real-time PCR. Chi-square tests were used to assess associations between variables.

RESULTS

Of the 176 patients, 109(62%) were males. The median age was 25[IQR,18-35] yr, with a range from 13 to 76 year. The prevalence of HBV (positivity for HBsAg plus HBV DNA), HCV and HIV was 21.6%, 1.7%, and 1.7%, respectively. HBsAg was positive in 19 cases (10.8%). Among 157 HBsAg negative patients, 52(33.1%) were positive for Anti-HBcAg; of these seropositive cases, 47.5% were positive for HBV DNA. Most DNA positive, HBsAg negative cases (79.0%) had DNA concentrations below 200 IU/ml indicating true occult HBV infection (OBI). Of the 176 cases, 122 had a history of blood transfusions, but no statistically significant association was found between HBV infection and blood product transfusion history (P = 0.963).

CONCLUSIONS

The prevalence of HBV, HIV and HCV in patients with acute leukemia was similar to the national prevalence level of these infections. Given the HBsAg positivity and the high prevalence of occult hepatitis B infection in our study, these patients may be at increased risk for chemotherapy related hepatitis flares. Hence, clinicians caring these patients are strongly advised to screen their patients for HBV and also for HIV and HCV infections routinely.

High Prevalence of Occult Hepatitis B Virus Infection among Iranian Hemodialysis Patients

Considering the potential risks associated with occult hepatitis B virus (HBV) infection, this study was designed to investigate the magnitude and genotypic pattern of occult HBV infection among hemodialysis patients. All patients on regular hemodialysis attending the dialysis centers located in southern Iran and 277 nonhemodialysis controls were invited to participate in this study. Serum samples were tested for detection of hepatitis B core antibody (HBcAb) and hepatitis B surface antigen (HBsAg) by competitive enzyme immunoassay and sandwich ELISA, respectively. The molecular evaluation of HBV infection was conducted by two nested polymerase chain reaction (PCR) assays, targeting S, X, and precore regions of HBV genome, and sequencing by Sanger dideoxy sequencing technology. Moreover, HBV viremic samples were tested for hepatitis C virus (HCV) coinfection by HCV Ab ELISA and seminested reverse transcriptase PCR. Of 279 hemodialysis patients, five (1.8%) were positive for HBsAg, 66 (23.7%) were positive for HBcAb, and 32 (11.5%) had HBV viremia with HBV genotype D, sub-genotype D3 and subtype ayw2. Moreover, 90.6% of the hemodialysis patients with HBV viremia had occult HBV infection. Hemodialysis patients (11.5%) had significantly higher prevalence of HBV viremia than nonhemodialysis controls (1.08%; P = 0.0001). The prevalence of HBV viremia among hemodialysis patients was not statistically associated with duration of hemodialysis, age and gender distribution. In contrast, HBV viremia was significantly associated with place of residency and ethnicity, with residents of Dashtestan and Arab having had significantly higher prevalence of HBV viremia compared with the residents of other cities and Fars patients. Notably, 27.6% and 6.9% of hemodialysis patients infected with occult HBV infection were also positive for anti-HCV antibodies and HCV viremia, respectively. High prevalence of occult HBV infection was detected in hemodialysis patients, whereas 62% of patients with occult HBV infection were negative for HBcAb. Therefore, screening of all hemodialysis patients by sensitive molecular tests, regardless of the pattern of HBV serological markers, is recommended to increase the diagnosis rate of HBV infection.