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

A preregistered meta-meta-analysis on the global distribution of Hepatotropic Viruses

INTRODUCTION

Hepatotropic viruses (HAV, HBV, HCV, HDV, and HEV) significantly impact global health, with varying prevalence across regions.

OBJECTIVE

This study aims to systematically consolidate data from diverse meta-analyses to provide a contemporary reference on virus distribution and prevalence.

MATERIALS AND METHODS

Adhering to PRISMA guidelines, the study utilized a mixed effects model for data integration. Quality evaluation was carried out with QUOROM and AMSTAR tools, with heterogeneity assessed via the Higgins I2 statistic, Q-statistic and Tau squared (τ2) values.

RESULTS

The study analyzed 86 meta-analyses from 56 studies (2017-2022) with minimal overlap. Prevalence rates by region were as follows: MENA - 29.2%, Afghanistan - 9.14%, Africa - 8.10%. Prevalence rates by virus type: HAV - 82.5%, HBV - 8.6%, HCV - 15.1%, HDV - 8.9%, HEV - 13.9%, dual HBV-HCV coinfection - 2.2%. Prevalence rates by risk groups: general population - 8.3%, healthcare workers - 4.0%. Continent-specific HBV-HCV prevalence rates: Africa - 9.2%, China - 6.9%, others. HCVprevalence rates among at-risk groups: healthcare workers - 5.58%, hemodialysis patients - 34.8%. Regional HCV rates: Africa - 7.42%, Middle East - 25.30%.

CONCLUSION

Diverse global hepatotropic virus prevalence patterns are influenced by multifaceted factors. MENA faces higher rates due to healthcare challenges, while Africa struggles with limited resources. Tailored public health strategies, including vaccination and awareness campaigns, are essential to alleviate burdens and enhance global health. This consolidated data serves as a valuable resource for informed decision-making.

[Delta hepatitis in Africa: epidemiological and clinical particularities]

In 2022, the World Health Organization (WHO) estimated that hepatitis B virus (HBV) infections caused 1.5 million deaths, mostly attributable to complications from chronic infections, cirrhosis and hepatocellular carcinoma (HCC). Despite the availability of a vaccine, 296 million people were chronically infected in 2019. Asia and Africa are the continents most affected by this infection, with around 100 million people infected in Africa as a whole.Hepatitis Delta or D virus (HDV), which is a "satellite" virus of HBV, is often misunderstood and its diagnosis remains neglected. However, it is associated with acute fulminant forms and chronic forms of hepatitis leading to a more rapid evolution towards cirrhosis and HCC than during HBV mono-infection. Research on these two viruses HBV and HDV has progressed a lot in recent years, and new treatments are currently in development.In people living with the human immunodeficiency virus (PlHIV), liver disease is a major cause of morbidity and mortality. Due to common modes of transmission, dual or triple HIV/HBV or HIV/HBV/HDV infections are relatively common, particularly in HBV endemic regions such as Africa. However, while today most co-infected patients benefit from effective treatment against both HIV and HBV, the latter is not active against HDV. In Africa, hepatitis B and D have already been the subject of several studies. However, the frequency and clinical consequences of these co-infections have been little studied in the general population and in PlHIV.This review seeks to update the epidemiological and clinical data and the therapeutic perspectives of HDV co-infections or triple infections (HIV-HBV-HDV) in Africa.

What Is the Real Epidemiology of Hepatitis D Virus and Why so Many Mixed Messages?

The disease burden of HDV is poorly understood. Our review identified multiple reasons: (1) HDV infection rates are overestimated in the general population due to limited sample sizes, sampling high-risk populations, and significant regional variations, (2) estimates are based on chronic HBV populations, but HBV burden itself is uncertain, (3) there is a lack of testing in at-risk populations, (4) prevalence testing is based on HDV antibody testing and not HDV RNA, which distinguishes between active infection versus prior exposure, (5) older studies used less reliable testing and (6) HBV vaccination programs have affected HDV prevalence, but is often not accounted for.

Hepatitis delta: Epidemiology to recent advances in therapeutic agents

Hepatitis D virus (HDV) was first described in 1977 and is dependent on the presence of hepatitis B surface antigen (HBsAg) for its entry into cells and on the human host for replication. Due to the envelopment with the hepatitis B virus (HBV) envelope, early phases of HDV entry resemble HBV infection. Unlike HBV, HDV activates innate immune responses. The global prevalence of HDV is estimated to be about 5% of HBsAg positive individuals. However, recent studies have described a wide range of prevalence between 12 to 72 million individuals. Infection can occur as super-infection or co-infection. The diagnosis of active HDV infection involves screening with anti HDV antibodies followed by quantitative PCR testing for HDV RNA in those who are HBsAg positive. The diagnostic studies have evolved over the years improving the validity and reliability of the tests performed. HDV infection is considered the most severe form of viral hepatitis and the HDV genotype may influence the disease course. There are eight major HDV genotypes with prevalence varying by geographic region. HDV treatment has been challenging as HDV strongly depends on the host cell for replication and provides few, if any viral targets. Better understanding of HDV virology has led to the development of several therapeutic agents currently being studied in different phase II and III clinical trials. There is increasing promise of effective therapies that will ameliorate the course of this devastating disease.

Delta hepatitis epidemiology and the global burden of disease

Delta Hepatitis is considered the most severe form of hepatitis, with varied prevalence, genotype distribution and risk factors worldwide. Current knowledge of global epidemiology is limited due to variable screening practices for HDV. Here, we summarize what is currently known about the prevalence of testing and prevalence of HDV positivity globally.

Hepatitis D virus infection in a large cohort of immigrants in southern Italy: a multicenter, prospective study

Background

Since few data are available in the literature on the prevalence of anti-Delta-positive subjects in immigrant populations, the aim of the present study was to evaluate the demographic and virological characteristics of HDV infection in a large cohort of immigrants living in southern Italy.

Methods

Between January 2012 and February 2020 all immigrants attending one of the 5 first- level centers were enrolled and screened for HBsAg, the HBsAg-positive for anti-Delta and if positive, for HDV-RNA and HDV genotype.

Results

Of the 3521 immigrants observed in the study period, 3417 (97.0%) agreed to be screened; they were mainly males (61%), with a median age of 27 years (IQR 8–74) and came prevalently (58%) from sub-Saharan Africa.

Of the 3417 patients enrolled, 319 (9%) subjects were HBsAg-positive, and of those, 8 (2.5%) were anti-Delta-positive. No difference in the demographic and epidemiological characteristics was observed between the anti-Delta-negative vs -positive. Of the 8 anti-Delta-positive subjects, only one was HDV-RNA-positive (viral load: 7050 IU/mL), genotype 1, with clinical signs of cirrhosis.

Conclusions

the present study showed a prevalence of HDV of 2.5% in a large cohort of asymptomatic immigrants, suggesting the need for screening campaigns for viral infections including delta hepatitis in this population.

Supplementary Information

The online version contains supplementary material available at 10.1007/s15010-022-01938-0.

Hepatitis D Review: Challenges for the Resource-Poor Setting

Hepatitis D is the smallest virus known to infect humans, the most aggressive, causing the most severe disease. It is considered a satellite or defective virus requiring the hepatitis B surface antigen (HBsAg) for its replication with approximately 10–70 million persons infected. Elimination of hepatitis D is, therefore, closely tied to hepatitis B elimination. There is a paucity of quality data in many resource-poor areas. Despite its aggressive natural history, treatment options for hepatitis D to date have been limited and, in many places, inaccessible. For decades, Pegylated interferon alpha (Peg IFN α) offered limited response rates (20%) where available. Developments in understanding viral replication pathways has meant that, for the first time in over three decades, specific therapy has been licensed for use in Europe. Bulevirtide (Hepcludex^®) is an entry inhibitor approved for use in patients with confirmed viraemia and compensated disease. It can be combined with Peg IFN α and/or nucleos(t)ide analogue for hepatitis B. Early reports suggest response rates of over 50% with good tolerability profile. Additional agents showing promise include the prenylation inhibitor lonafarnib, inhibitors of viral release (nucleic acid polymers) and better tolerated Peg IFN lambda (λ). These agents remain out of reach for most resource limited areas where access to new therapies are delayed by decades. strategies to facilitate access to care for the most vulnerable should be actively sought by all stakeholders.

Viral hepatitis associated hepatocellular carcinoma on the African continent, the past, present, and future: a systematic review

Background

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths in Africa. In Africa, the major causes of HCC include chronic infection with hepatitis B virus (HBV) and/or hepatitis C virus (HCV). Knowledge of the changes in the incidence of viral hepatitis-associated HCC over time and the factors responsible for such changes is key in informing policies for the prevention of viral hepatitis-associated HCC in Africa.

Aim

The study aimed to systematically summarize the changes in the prevalence of viral hepatitis among HCC patients and the overall effect of the prevalence of viral hepatitis on the incidence of HCC over the past four decades in Africa (1980–2019).

Methods

A literature search was conducted in MEDLINE (PubMed), Google Scholar, Science Direct, Scopus, Web of Science, and African wide web for articles published on viral hepatitis-associated HCC in Africa from 1980 to 2019. The abstracts of the articles were screened for eligibility and those meeting the inclusion criteria were retrieved and reviewed.

Results

A total of 272 studies were included in the analysis. Viral hepatitis-related HCC incidence changed by 1.17% (95% confidence interval (CI): 0.63–1.71, p < 0.001), 0.82% (95% CI: 0.45–1.18, p < 0.001), and 3.34% (95% CI: 2.44–4.25, p < 0.001) for every 1% change in the prevalence of HBV, HCV, and hepatitis D virus (HDV) respectively, per decade. The incidence of HBV-related HCC decreased by − 0.50% (95% CI: − 0.74 – − 0.25, p < 0.001) over the last 40 years, while HCV-related HCC increased.

Conclusion

Overall, the incidence of viral hepatitis-associated HCC has not declined, mainly due to no decline in the prevalence of HCV, HDV, and the high number of chronic hepatitis B carriers on the African continent. There is an urgent need for the allocation of resources for the implementation of treatment and preventive programs for HBV, HCV, HDV, and HCC in Africa.

This systematic review is registered with PROSPERO®, number CRD42020169723.

Epidemiological characterization and geographic distribution of human immunodeficiency virus/acquired immunodeficiency syndrome infection in North African countries

BACKGROUND

Human immunodeficiency virus (HIV) infection is a major global public health concern. North African countries carry a disproportionate burden of HIV representing one of the highest rates in Africa.

AIM

To characterize the epidemiological and spatial trends of HIV infection in this region.

METHODS

A systematic review was carried out on all the published data regarding HIV/acquired immunodeficiency syndrome in North African countries over ten years (2008-2017) following the PRISMA guidelines. We performed a comprehensive literature search using Medline PubMed, Embase, regional and international databases, and country-level reports with no language restriction. The quality, quantity, and geographic coverage of the data were assessed at both the national and regional levels. We used random-effects methods, spatial variables, and stratified results by demographic factors. Only original data on the prevalence of HIV infection were included and independently evaluated by professional epidemiologists.

RESULTS

A total of 721 records were identified but only 41 that met the criteria were included in the meta-analysis. There was considerable variability in the prevalence estimates of HIV within the countries of the region. The overall prevalence of HIV ranged from 0.9% [95% confidence interval (CI) 0.8-1.27] to 3.8% (95%CI 1.17-6.53). The highest prevalence was associated with vulnerable groups and particularly drug abusers and sexually promiscuous individuals. The dense HIV clustering noted varied from one country to another. At least 13 HIV subtypes and recombinant forms were prevalent in the region. Subtype B was the most common variant, followed by CRF02_AG.

CONCLUSION

This comprehensive review indicates that HIV infection in North African countries is an increasing threat. Effective national and regional strategies are needed to improve monitoring and control of HIV transmission, with particular emphasis on geographic variability and HIV clustering.

The epidemiological characterization and geographic distribution of hepatitis D virus infection in Libya

Introduction

North Africa is known to be endemic for hepatitis D virus. However, data one the prevalence of this virus in Libya are scanty. This study aimed to determine the prevalence of hepatitis D virus infection in Libya and analyze the demographic factors associated with the infection, and also to assess the variations across the regions and districts.

Methods

A total of 1873 samples collected from all over the country were tested for antibodies against hepatitis B surface antigen and the results were correlated with demographic and geographic variables.

Results

The overall prevalence of hepatitis D virus infection was 1.7%. The prevalence rate was significantly high among those aged over 40 years (P < 0.001) and it was associated with intravenous drug use and coinfection with human immunodeficiency virus and/or hepatitis C virus infection (P < 0.001). The prevalence rates varied with geographic location and differed markedly within the regions the country. The highest rate reported was in the central region of Libya, followed by the western and eastern regions.

Conclusion

Hepatitis D virus infection rate in Libya is considered to be low but is of some concern in some districts. This has been propagated by population displacement and African immigrants, indicating that a continuous epidemiological surveillance program should be implemented.

HDV infection in immigrant populations

AIMS

Little data have been published so far on the epidemiological aspects of hepatitis D virus (HDV) infection in immigrant populations and even poorer is the information on the virological, phylogenetic, and clinical aspects of this infection in these populations. This review article, aimed primarily at physicians caring for immigrants, summarizes the information available on HDV infection and analyzes data on this topic concerning the immigrant populations.

METHODS AND RESULTS

The prevalence of HDV infection in HBsAg-positive immigrants varies according to the country of origin. For example, in immigrants from sub-Saharan Africa, this prevalence is higher in those born in Equatorial Guinea (24.4%) than those from other African countries (10.3%). The epidemiological impact of HDV infection linked to migratory flows is a function of the different endemicity between countries of origin and countries in which a new existence has been established. This impact is high when immigrants from areas endemic to HDV infection (eg, Equatorial Guinea) settle in areas of low endemicity (eg, Germany or England, with a prevalence of around 4%), while the impact is lesser or nonexistent if the migratory flows are directed toward countries with intermediate endemicity (eg, Italy and Greece, with a prevalence of around 10%).

CONCLUSION

This impact of immigration on HDV epidemiology can be strong when HDV endemicity is high in the country of origin and low in the host country and slight when immigrants move to high or medium endemic countries.

Spatiotemporal analysis and epidemiological characterization of the human immunodeficiency virus (HIV) in Libya within a twenty five year period: 1993-2017

Background

Infection with the human immunodeficiency virus (HIV) is an alarming problem in North African countries, but few studies have analyzed the geographical distribution of the epidemic. Libya, the second largest country in Africa and with the longest coast on the Mediterranean basin facing Europe, has experienced major outbreaks of HIV infection. Since then, no studies have followed up on the burden of HIV infections. To plan interventions and allocate resources, spatial analysis of HIV/AIDS clusters are required in order to identify epidemic foci and trends in the country. The objective of this study was to assess HIV infection clustering and trends in Libya.

Methods

Information on all recorded HIV/AIDS cases during 1993–2017 were extracted from the National Reporting System. A total of 8015 newly diagnosed HIV cases with address information were included. Spatial autocorrelation and spatial–temporal analysis were used to identify HIV clusters. Spatial correlations between cases and socio-demographic factors were determined using spatial regression.

Results

HIV cases steadily increased within the Libyan population, particularly among those aged < 27 years. Spatiotemporal analysis showed marked geographic and temporal variation of HIV infection, particularly during 2005–2012. The risk factors varied from one region to another, and the contribution of injection drug use to infection increased with time. Four clusters in three time periods were identified, three on the Mediterranean coast and one in the south.

Conclusion

HIV is an emerging problem in Libya, particularly among young adults. The infection rate varies greatly among the regions and districts, particularly within certain definable geographical areas. Effective intervention strategies are needed to contain HIV infections, especially within the endemic areas.

Electronic supplementary material

The online version of this article (10.1186/s12981-019-0228-0) contains supplementary material, which is available to authorized users.

The geographic variation and spatiotemporal distribution of hepatitis C virus infection in Libya: 2007-2016

BACKGROUND

Hepatitis C Virus infection has been considered an important hidden pandemic in developing countries, particularly in Africa. It varies greatly from one region to another and even within districts of the same region. Macroscopic geospatial analysis has become an important scientific tool for identifying the density and clustering of HCV infection and provides epidemiological information for planning interventions and control strategies. The application of these parameters provides a better knowledge of the hepatitis C virus infection prevalence at the national level and can help to implement pertinent strategies to address the HCV-related burdens. This study aims to determine the geographical variability of HCV infection in Libya and to identify the hot spots within regions and districts of the country, and to analyze the population-based demographic determinants involved and outline the intervention programs needed.

METHODS

Disease mapping and spatial analysis were conducted using geographic information data available on all documented cases of HCV infections in Libya between 2007 and 2016. Spatial autocorrelation was tested using Moran's Index, which determines and measures the degree of clustering and dispersion of HCV infection in a country.

RESULTS

A total 114,928 HCV infection cases during a ten-year period with accurate geographic information were studied. Ages ranged between 16 and 50 years and the male to female ratio was 2:1. HCV infection was unevenly distributed in Libya, and its incidence increased steadily over the study period. Several hot spots and cold spots were found mainly in the southern and eastern regions of the country.

CONCLUSION

HCV infection in Libya was geographically variable, with several hot spots particularly in eastern and southern Libya associated with different demographic determinants. Future intervention planning should consider the geospatial variability and risk factors involved.