Hepatitis D Virus Infection Among Hepatitis B Surface Antigen Carriers and in "Isolated anti-HBc" Antibodies Profile in Central Tunisia

Improving Access to Anti-HDV Testing: Development and Validation of an Affordable In-House ELISA Assay

In certain low-income nations, the hepatitis Delta virus and hepatitis B virus (HBV) pose a serious medical burden, where the prevalence of hepatitis B surface antigen (HBsAg) is greater than 8%. Especially in rural places, irregular diagnostic exams are the main restriction and reason for underestimation. Utilizing serum samples from a Pakistani isolate, an internal ELISA for the quick identification of anti-HDV was created, and the effectiveness of the test was compared to a commercial diagnostic kit. HDV-positive serum samples were collected, and a highly antigenic domain of HDAg antigen was derived from them. This antigenic HDAg was expressed in a bacterial expression system, purified by Ni-chromatography, and confirmed by SDS-PAGE and Western blot analysis. The purified antigen was utilized to develop an in-house ELISA assay for anti-HDV antibody detection of the patient's serum samples at very low cost. Purified antigens and positive and negative controls can detect anti-HDV (antibodies) in ELISA plates. The in-house developed kit's efficiency was compared with that of a commercial kit (Witech Inc., USA) by the mean optical density values of both kits. No significant difference was observed (a P value of 0.576) by applying statistical analysis. The newly developed in-house ELISA is equally efficient compared to commercial kits, and these may be useful in regular diagnostic laboratories, especially for analyzing local isolates.

No Hepatitis Delta Virus Seropositivity among Blood Donors with Overt and Occult Hepatitis B Infection in Dalian, Liaoning Province, China

Hepatitis delta virus (HDV) is an obligate satellite of hepatitis B virus (HBV). Dual HDV/HBV infection is associated with down-regulated HBV replication and fast progression to severe liver disease. Although HDV is transmissible through exposure to infected blood, data about HDV infection in blood donors remain scarce. Between 2011 and 2021, 869,633 donations were collected from prequalified donors in Dalian, China. In total, 1060 (0.12%) were confirmed HBsAg and/or HBV DNA-reactive. Subsequently, anti-HDV IgG was tested in 2175 donations, including 65 that tested HBsAg+ pre donation, 1017 confirmed HBV-positive (507 HBsAg+/HBV DNA+, 33 HBsAg+/DNA-, 477 HBsAg-/DNA+ (451 occult (OBI) and 26 acute infections)), 327 viral DNA non-repeated-reactive, 397 anti-HBc-only, and 369 anti-HBs-only. Two (0.09%) samples tested anti-HDV IgG weakly reactive but were unconfirmed by IgM and IgG repeat testing with alternative assays, suggesting an initial false reactivity. In addition, HDV testing in a subgroup of confirmed OBI donors, comprising 451 donors from Dalian and 126 archived samples of OBI donors from around the world, showed only one non-Chinese donor to be repeatedly anti-HDV-reactive, suggesting that HDV/HBV coinfection does not play a significant role in the genesis of OBI. The overall data suggested an extremely low prevalence of HDV infection among blood donors in Liaoning province, Northeast China.

The changing context of hepatitis D

The global epidemiology of hepatitis D is changing with the widespread implementation of vaccination against hepatitis B. In high-income countries that achieved optimal control of HBV, the epidemiology of hepatitis D is dual, consisting of an ageing cohort of domestic patients with advanced liver fibrosis who represent the end stage of the natural history of HDV, and of a younger generation of immigrants from endemic countries who account for the majority of new infections. As observed in Europe in the 1980s, the distinctive clinical characteristic of chronic hepatitis D in endemic countries is the accelerated progression to cirrhosis and hepatocellular carcinoma. Despite some recent progress, the therapeutic management of HDV remains unsatisfactory, as most patients are not cured of HDV with currently available medicines. This review article describes the current epidemiology and clinical features of chronic hepatitis D, based on the literature published in the last 10 years.

Prevalence of Hepatitis Delta Virus Infection among Hepatitis B Virus-Infected and Exposed Patients

Background:

Hepatitis delta virus (HDV) infection is a cause of coinfection and superinfection among hepatitis B virus (HBV)-infected patients. The global prevalence of HDV may vary drastically depending on the geographical location. In India, serological techniques form the basis for the determination of HDV prevalence in majority of the studies with very limited literature based on molecular techniques. In addition, sparse data on HDV infection among HBV-exposed group, i.e., patients with total antibodies to core antigen (anti-hepatitis B core [HBc]) positive and negative hepatitis B surface antigen (HBsAg), are available.

Objective:

This study was aimed to determine the prevalence of HDV in both HBV-infected and HBV-exposed groups, utilizing both serological and molecular methods.

Settings and Design:

This was a retrospective cross-sectional study conducted from January till June 2018 where samples of 142 patients were retrieved and were categorized into two groups: Group A included patients with both HBsAg and anti-HBc positivity (n = 120/142 [85%]), i.e., confirmed HBV infection, and Group B included patients with anti-HBc positivity and HBsAg negativity (n = 22/142 [15%]), i.e., exposed to HBV.

Materials and Methods:

All the specimens were retrieved from −80°C and were tested for anti-HDV immunoglobulin (Ig) M (IgM), anti-HDV IgG, and HDV RNA.

Results:

HDV infection was observed in only one patient in Group A and none in Group B, making an overall prevalence of 0.78% (95% confidence interval = 0.02%–3.9%). The infected patient was reactive for both IgM and IgG with a viral load of 2log₁₀IU/ml.

Conclusion:

The present study provides evidence that HDV infection is very low(0.78%) in this part of India. However further prospective studies with larger sample size are warranted.

The Epidemiology of Hepatitis D Virus in North Africa: A Systematic Review and Meta-Analysis

BACKGROUND

Hepatitis D virus (HDV) infection has been considered a serious neglected pandemic, particularly in developing countries. The virus causes a more severe disease than mono infection with hepatitis B virus (HBV). The epidemiology of HDV is not well documented in North Africa, which is known to be endemic for HBV. In this study, we explored the prevalence of HDV infection and also attempted to identify factors associated with hepatitis D positive status among chronic hepatitis B patients in North Africa.

METHODS

The electronic databases PubMed, Embase, Scopus, Science Direct, Web of Science, and Google Scholar were comprehensively searched for all papers published between January 1, 1998, and December 31, 2017, using appropriate strategies containing all related keywords, including North Africa, names of countries in the region, and all permutations of hepatitis D virus. The estimated prevalence of HDV in North Africa was calculated as an average of the pooled infection prevalence in each country weighted by the ratio of the country's hepatitis D virus population to the study's sample size in the survey data analysis.

FINDINGS

A total of 312 studies were identified and 32 were included in this study, with a total sample of 4907 individuals screened for HDV. There was considerable variability in the prevalence estimates of HDV within the countries of the region. The overall prevalence of HDV in the general population of North Africa was 5·01% (95% CI: 1·25-8·27) and in liver disease patients it was 20.7% (95% CI:9.87-44.53). Genotype-1 was the most prominent genotype reported in five published studies. Ten studies reported on HDV RNA in participants who were seropositive for HDV, and four studies highlighted the impact of demographic factors (sex and age). No study showed the impact of risk factors on the prevalence of HDV in North Africa.

INTERPRETATION

This review provides a comprehensive assessment of the burden of HDV in Northern Africa. There were significant differences in seroprevalence, study population, and diagnostic testing between the countries in the region. The results presented here will alert health professionals to implement clear policies based on evidence to diminish the burden of HDV infection. Such measures may include but are not restricted to improving the laboratory diagnostic tests and initiating patient data registries and blood screening. Further epidemiological and research studies are needed to explore the risk factors, coinfections, and approaches to increase testing for HDV, particularly in high-risk subpopulations, such as intravenous drug users and immigrants, and to define the consequences of HDV infection in North Africa.

Prevalence and risk factors of hepatitis B and C among hemodialysis patients in Tunisia

OBJECTIVE

Hemodialysis patients are at increased risk of infection by hepatitis C and B viruses, which are significant causes of mortality and morbidity. Prevention of their transmission in hemodialysis units remains a challenge worldwide. We aimed to investigate the prevalence of these two infections and to explore major risk factors among patients on chronic hemodialysis.

MATERIALS AND METHODS

We performed a cross-sectional study of 109 hemodialysis patients (mean duration of hemodialysis of seven years) between 2012 and 2014 in a Teaching Hospital of Monastir, Tunisia. Hepatitis B and C serological markers were searched for using a chemiluminescent assay. Genome detection was performed using a commercially available quantitative real-time PCR test.

RESULTS

A total of 109 hemodialysis patients were enrolled (75 males and 34 females). Ages ranged from 21 to 81 years. Six (5.5%) of these 109 patients had HBV infection defined by a positive HBsAg in four (3.7%) patients and by a detectable DNA associated with an "isolated anti-HBc" profile in the remaining two patients. Hepatitis C was observed in eight patients (7.3%) and five of them had detectable RNA. Hemodialysis duration ˃5years was the main risk factor for hepatitis C infection (P=0.01; OR: 3.11; 95% CI [1.57-13.71]).

CONCLUSION

Our findings confirm the downward trend of the prevalence of both hepatitis B and C infections among Tunisian hemodialysis patients. Hemodialysis duration remains the main risk factor for hepatitis C infection. Occult hepatitis B infection should be suspected and investigated, especially among patients with an "isolated anti-HBc" profile.

Prevalence and risk factors of hepatitis D virus infection in patients with chronic hepatitis B infection attending the three main tertiary hospitals in Libya

BACKGROUND AND STUDY AIMS

Globally, More than 350 million individuals are chronically infected with hepatitis B virus (HBV), and >20 million of them are co-infected with hepatitis D virus (HDV). The aim of this study was to determine the pattern of HDV infection in patients with chronic hepatitis B in three main tertiary hospitals in Tripoli and Benghazi, Libya.

PATIENTS AND METHODS

This cross sectional and descriptive study was conducted on 162 patients with chronic hepatitis B positive for more than six months) who were followed up at hepatitis clinics of the three main tertiary hospitals in Tripoli city (88 patients from Tripoli Medical Centre and Tripoli Central Hospital) and Benghazi city (74 patients from Aljomhoria Hospital) during the period from January 2010 to June 2012. HBV and HDV markers were detected by enzyme linked fluorescent assay (ELFA) or enzyme-linked immunosorbent assay and HBV-DNA was quantified by real-time PCR techniques.

RESULTS

The mean age of patients was 36,92 ± 15,35. One hundred and three (63.6%) of them were males and 59 (36,4%) were females. Four patients (2,5%) were tested positive for anti-HD antibodies, all of them have had clinical and/or histological diagnosis of cirrhosis. In multivariable regression analysis, age (p = .04), elevation of serum ALT (p = .03), elevation of serum AST (p = .04), and presence of cirrhosis (p = .003) were significantly related to HDV seropositivity.

CONCLUSION

Although the study demonstrated that Libya has low to moderate prevalence of HDV (2,5%), it is important for policy makers and health care providers to continue the preventive measures for HDV spread, and HBV prevention program including utilization of HBV vaccine. Furthermore, it is imperative to screen chronic HBV patients for HDV for close observation for early diagnosis of subsequent development of liver cirrhosis. Moreover, further epidemiologic and genetic studies are needed to explore the trend for HDV infection in Libya.