Epidemiology of hepatitis E virus infection in animals in Africa: a systematic review and meta-analysis.

BACKGROUND: Hepatitis E virus (HEV) is a major cause of acute hepatitis in humans worldwide and have high burden in the resource-limited countries. Better knowledge of the epidemiology of hepatitis in animals in Africa can help to understand the epidemiology among humans. The objective of this study was to summarize the prevalence of HEV infection and distribution of HEV genotypes among animals in Africa. METHODS: In this systematic review and meta-analysis, we comprehensively searched PubMed, EMBASE, African Journals Online, and Africa Index Medicus from January 1st, 2000 to March 22th, 2020 without any language restriction. We considered cross-sectional studies of HEV infection in animals in Africa. Study selection, data extraction, and methodological quality of included studies were done independently by two investigators. Prevalence data were pooled using the random-effects meta-analysis. This review was registered in PROSPERO, CRD42018087684. RESULTS: Twenty-five studies (13 species and 6983 animals) were included. The prevalence (antibodies or ribonucleic acid [RNA]) of HEV infection in animals varied widely depending on biological markers of HEV infection measured: 23.4% (95% confidence interval; 12.0-37.2) for anti-HEV immunoglobulins G, 13.1% (3.1-28.3) for anti-HEV immunoglobulins M, and 1.8% (0.2-4.3) for RNA; with substantial heterogeneity. In subgroup analysis, the immunoglobulins G seroprevalence was higher among pigs 37.8% (13.9-65.4). The following HEV genotypes were reported in animals: Rat-HEV genotype 1 (rats and horses), HEV-3 (pigs), HEV-7 (dromedaries), and Bat hepeviruses (bats). CONCLUSIONS: We found a high prevalence of HEV infection in animals in Africa and HEV genotypes close to that of humans. Some animals in Africa could be the reservoir of HEV, highlighting the need of molecular epidemiological studies for investigating zoonotic transmission.

Burden of hepatitis E virus infection in pregnancy and maternofoetal outcomes: a systematic review and meta-analysis.

BACKGROUND: There is still a dearth of knowledge on the burden of HEV infection in the global population of pregnant women. Therefore, we conducted a systematic review and meta-analysis to estimate the global burden of HEV infection in pregnancy. METHODS: We searched PubMed, Embase, Web of Knowledge, and Global Index Medicus to identify articles published until January 26, 2020. We considered cross-sectional, case-control, and cohort studies reporting the immunoglobulins M HEV seroprevalence in asymptomatic and symptomatic (jaundice or elevated transaminases) pregnant women or investigating the association between HEV infection and maternofoetal outcomes. We used a random-effects model to pool studies. This review was registered with PROSPERO, CRD42018093820. RESULTS: For HEV prevalence estimates, we included 52 studies (11,663 pregnant women). The seroprevalence was 3.5% (95% confidence interval: 1.4-6.4) in asymptomatic women (most of whom from high endemic areas). The prevalence in symptomatic women was 49.6% (42.6-56.7) with data only from HEV high endemic countries. In the multivariable meta-regression model, the prevalence was higher in symptomatic women compared to asymptomatic (adjusted prevalence odds ratio [aPOR]: 1.76; 95%CI: 1.61-1.91) and decreased with increasing year of publication (by 10-year) (aPOR: 0.90; 95%CI: 0.84-0.96). The proportion of HEV vertical transmission was 36.9% (13.3-64.2). Risk of bias was low, moderate and high respectively in 12 (23%), 37 (70%), and 4 studies (7%) addressing HEV prevalence estimation. HEV infection was associated with maternal deaths (pooled OR 7.17; 3.32-15.47), low birth weight (OR: 3.23; 1.71-6.10), small for gestational age (OR: 3.63; 1.25-10.49), preterm < 32 weeks (OR: 4.18; 1.23-14.20), and preterm < 37 weeks (OR: 3.45; 2.32-5.13), stillbirth (OR: 2.61; 1.64-4.14), intrauterine deaths (OR: 3.07; 2.13-4.43), and not with miscarriage (OR: 1.74; 0.77-3.90). All studies which assessed the association between HEV infection and maternofoetal outcomes had a moderate risk of bias. CONCLUSIONS: Findings from this study are suggestive of a high burden of HEV infection in pregnancy in high endemic countries, its association with poor maternofoetal outcomes, and a high rate of vertical transmission. This study supports the need for specific strategies to prevent exposure of pregnant women to HEV infection, especially in high endemic areas.

Global Burden of Hepatitis B Infection in People Living With Human Immunodeficiency Virus: A Systematic Review and Meta-analysis.

BACKGROUND: This meta-analysis was conducted to estimate the global burden of hepatitis B virus (HBV) infection in people living with human immunodeficiency virus (PLWH). METHODS: We searched multiple databases for studies published between January 1990 and December 2017. HBV infection (hepatitis B surface antigen) was diagnosed with serological assays. A random-effects meta-analysis served to pool data. RESULTS: We included 358 studies (834 544 PLWH from 87 countries). The pooled prevalence of HBV infection was 8.4% (95% confidence interval [CI], 7.9%-8.8%), among which 26.8% (95% CI, 22.0%-31.9%) was positive to hepatitis B e antigen. HBV prevalence (with 95% CIs) differed according to region: West and Central Africa, 12.4% (11.0%-13.8%); Middle East and North Africa, 9.9% (6.0%-14.6%); Asia and the Pacific, 9.8% (8.7%-11.0%); Eastern and Southern Africa, 7.4% (6.4%-8.4%); Western and Central Europe and North America, 6.0% (5.5%-6.7%); and Latin America and the Caribbean, 5.1% (4.2%-6.2%) (P < .0001). The prevalence decreased from 10.4% in low-developed to 6.6% in highly developed countries (P < .0001) and increased from 7.3% in countries with HIV prevalence ≤1% to 9.7% in countries with HIV prevalence >1% (P < .0001). Globally, we estimated that there were 3 136 500 (95% CI, 2 952 000-3 284 100) cases of HBV in PLWH, with 73.8% of estimated regional cases from sub-Saharan Africa and 17.1% from Asia and the Pacific. CONCLUSIONS: This study suggests a high burden of HBV infection in PLWH, with disparities according to region, level of development, and country HIV prevalence.

Gender development and hepatitis B and C infections among pregnant women in Africa: a systematic review and meta-analysis.

BACKGROUND: Although Africa is a region of hyper endemicity to viral hepatitis B (HBV) and C (HCV) infections, there is limited data on their related burden among pregnant women. The present systematic review and meta-analysis aimed to determine the magnitude of these infections among pregnant women living in Africa and investigate its association with gender-related human development indicators. MAIN TEXT: We searched PubMed, Embase, Web of Science, Africa Journal Online, and Global Index Medicus, with no language restriction, to identify observational studies on HBV and HCV infections in pregnant women residing in Africa published from January 1, 2000 until December 31, 2017. Eligible studies reported the prevalence of HBV and/or HCV infection(s) (HBs antigen and HCV antibodies) and/or infectivity (HBe antigen or detectable HCV viral load). Each study was independently reviewed for methodological quality. We used a random-effects model meta-analysis to pool studies. In total, 145 studies (258 251 participants, 30 countries) were included, of which 120 (82.8%) had a low, 24 (16.5%) a moderate, and one (0.7%) had a high risk of bias. The prevalence of HBV and HCV infections was 6.8% (95% confidence interval [CI]: 6.1-7.6, 113 studies) and 3.4% (95% CI: 2.6-4.2, 58 studies), respectively. The prevalence of HBe antigen and HCV detectable viral load was 18.9% (95% CI: 14.4-23.9) and 62.3% (95% CI: 51.6-72.5) in HBV positive and HCV positive pregnant women, respectively. The multivariable meta-regression analysis showed that the prevalence of HBV infection increased with decreasing gender development index, males' level of education and females' expected years of schooling. Furthermore, this prevalence was higher in rural areas and in western and central Africa. The prevalence of HCV infection increased with decreasing proportion of seats held by women in parliament. CONCLUSIONS: To address the burden of HBV and HCV infections, beyond well-known risk factors at the individual-level, macro-level factors including gender-related human development indicators and dwelling in rural areas should be considered. In Africa, HBV or HCV infected mothers seems to have high potential of transmission to their children.

Global, regional, and national prevalence of hepatitis B infection in the general and key populations living with HIV: a systematic review and meta-analysis protocol.

BACKGROUND: Hepatitis B causes death mainly due to liver disease worldwide. Human immunodeficiency virus increases the pathological effect of hepatitis viruses and potentiates re-activation of latent hepatitis infections as a result of reduced immunity. Because of the same modes of transmission shared by the two infections, HBV represents an important cause of co-morbidity and mortality among people living with HIV; hence, the aim of this review is to determine the prevalence of HBV among people living with HIV. METHODS: This systematic review and meta-analysis will include cross-sectional, case-control, and cohort studies of patients positive for HBV and HIV irrespective of their countries. All pertinent articles published on hepatitis B in people living with HIV from January 1, 1990, to July 31, 2017, without any language restriction will be searched in PubMed/MEDLINE, Global Index Medicus Web of Science, and Excerpta Medica Database. Two review authors will independently assess the relevance of all titles and abstracts identified from the electronic searches. The study-specific estimates will be pooled through a random-effects meta-analysis model to obtain an overall summary estimate of the prevalence of HBV across studies. We will assess statistical heterogeneity and pool clinically homogeneous studies. On the other hand, we will evaluate statistical heterogeneity by the chi-squared test on Cochrane's Q statistic. Symmetry of funnel plots and Egger's test will be used to detect the presence of publication and selective reporting bias. In the case of publication bias, we will report estimates after adjustment on publication bias using the trim-and-fill method. We will assess inter-rater agreement between investigators for study inclusion, data extraction, and methodological quality assessment using Kappa Cohen's coefficient. This protocol will comply with the guidelines for meta-analyses and systematic reviews of Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA). DISCUSSION: To our knowledge, this is the first systematic review and meta-analysis protocol to report the prevalence of HBV in people living with HIV. We believe its outcomes will be of utility in providing insights on the characteristics of HBV epidemic in people living with HIV, and draw more attention of public health services to this association. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42017073124.

Seroprevalence of hepatitis C virus infection in Cameroon: a systematic review and meta-analysis.

OBJECTIVE: Better knowledge of hepatitis C virus (HCV) seroprevalence at the national level can help to implement pertinent strategies to address the HCV-related burden. The aim of this paper was to estimate the seroprevalence of HCV infection in Cameroon. DESIGN: Systematic review and meta-analysis. PARTICIPANTS: People residing in Cameroon. DATA SOURCES: Electronic databases including PubMed/MEDLINE, AJOL, WHO-Afro Library, Africa Index Medicus, National Institute of Statistics and National AIDS Control Committee, Cameroon from 1 January 2000 to 15 December 2016 were searched. English and French languages papers were considered. Two independent investigators selected studies. The methodological quality of the studies was assessed using the Newcastle-Ottawa scale. RESULTS: 31 studies including 36 407 individuals were finally considered. There was no national representative study. The overall pooled prevalence was 6.5% (95% CI 4.5% to 8.8%; I²=98.3%). A sensitivity analysis of individuals at low risk of HCV infection showed a pooled prevalence of 3.6% (95% CI 2.3% to 5.2%, I²=97.7%, 18 studies) among 22 860 individuals (general population, blood donors and pregnant women), which was higher than for a high-risk population (healthcare workers and people with other identified comorbidities), 12.2% (95% CI 4.9% to 22.2%; I²=98.3%, 13 studies); p=0.018. The prevalence was higher in the East region, in rural settings, and when using an enzyme immunoassay technique for detecting HCV antibodies. Sex, sites, study period, sample size, timing of data collection and methodological quality of studies were not sources of heterogeneity. LIMITATION: One-third of studies (29.0%) had a low risk bias in their methodology and most were facility-based (87.1%). CONCLUSION: The seroprevalence of HCV infection in Cameroon indicates the need for comprehensive and effective strategies to interrupt HCV transmission in the Cameroonian population. Specific attention is needed for the East region of the country, rural settings and high-risk populations. A national representative study is needed to provide better estimates.

Seroprevalence of hepatitis B virus infection in Cameroon: a systematic review and meta-analysis.

OBJECTIVE: Better knowledge of hepatitis B virus (HBV) infection prevalence at the national level can help to implement pertinent strategies to address HBV related burden. The aim was to estimate the seroprevalence of HBV infection in Cameroon. DESIGN: Systematic review and meta-analysis. PARTICIPANTS: People residing in Cameroon. DATA SOURCES: Electronic databases including PubMed/MEDLINE, African Journals Online (AJOL), ScienceDirect, WHO-Afro Library, WHO-IRIS, African Index Medicus, National Institute of Statistics and National AIDS Control Committee, Cameroon; regardless of language and from 1 January 2000 to 30 September 2016. This was completed with a manual search of references of relevant papers. Risk of bias in methodology of studies was measured using the Newcastle-Ottawa Scale. RESULTS: Out of 511 retrieved papers, 44 studies with a total of 105 603 individuals were finally included. The overall pooled seroprevalence was 11.2% (95% CI 9.7% to 12.8%) with high heterogeneity between studies (I2=97.9%). Egger's test showed no publication bias (p=0.167). A sensitivity analysis excluding individuals at high risk of HBV infection and after adjustment using trim and fill method showed a pooled seroprevalence of 10.6% (95% CI 8.6% to 12.6%) among 100 501 individuals (general population, blood donors and pregnant women). Sources of heterogeneity included geographical regions across country and setting (rural 13.3% vs urban 9.0%), and implementation of HBV universal immunisation (born after 9.2% vs born before 0.7%). Sex, site, timing of data collection, HBV screening tools and methodological quality of studies were not sources of heterogeneity. LIMITATION: Only a third of the studies had low risk of bias in their methodology. CONCLUSION: The seroprevalence of HBV infection in Cameroon is high. Effective strategies to interrupt the transmission of HBV are urgently required. Specific attention is needed for rural settings, certain regions and people born before the implementation of the HBV universal immunisation programme in Cameroon in 2005. REGISTRATION: PROSPERO, CRD42016042654.