Seroprevalence and risk factors of Hepatitis E virus infection among pregnant women attending antenatal care in health facilities of Tigray, Northern Ethiopia

Hepatitis E Virus Seroprevalence and Associated Risk Factors in Pregnant Women Attending Antenatal Consultations in Senegal

In West Africa, research on the hepatitis E virus (HEV) is barely covered, despite the recorded outbreaks. The low level of access to safe water and adequate sanitation is still one of the main factors of HEV spread in developing countries. HEV infection induces acute or sub-clinical liver diseases with a mortality rate ranging from 0.5 to 4%. The mortality rate is more alarming (15 to 25%) among pregnant women, especially in the last trimester of pregnancy. Herein, we conducted a multicentric socio-demographic and seroepidemiological survey of HEV in Senegal among pregnant women. A consecutive and non-redundant recruitment of participants was carried out over the period of 5 months, from March to July 2021. A total of 1227 consenting participants attending antenatal clinics responded to a standard questionnaire. Plasma samples were collected and tested for anti-HEV IgM and IgG by using the WANTAI HEV-IgM and IgG ELISA assay. The overall HEV seroprevalence was 7.8% (n = 96), with 0.5% (n = 6) and 7.4% (n = 91) for HEV IgM and HEV IgG, respectively. One of the participant samples was IgM/IgG-positive, while four were declared indeterminate to anti-HEV IgM as per the manufacturer’s instructions. From one locality to another, the seroprevalence of HEV antibodies varied from 0 to 1% for HEV IgM and from 1.5 to 10.5% for HEV IgG. The data also showed that seroprevalence varied significantly by marital status (p < 0.0001), by the regularity of income (p = 0.0043), and by access to sanitation services (p = 0.0006). These data could serve as a basis to setup national prevention strategies focused on socio-cultural, environmental, and behavioral aspects for a better management of HEV infection in Senegal.

Potential role of viral infections in miscarriage and insights into the underlying molecular mechanisms

Intrauterine viruses can infect the decidua and placenta and cause adverse effects on the fetus during gestation. This review discusses the contribution of various viral infections to miscarriage and the molecular mechanisms by which viruses can cause devastating effects on healthy fetuses and induce miscarriage. Severe acute respiratory syndrome coronavirus 2 as newly emerged coronavirus was considered here, due to the concerns about its role during pregnancy and inducing miscarriage, as well. In this narrative review, an extensive literature search was conducted to find all studies investigating viral infections in miscarriage and their molecular mechanisms published over the past 20 years. The results of various studies investigating the roles of 20 viral infections in miscarriage are presented. Then, the mechanisms of pregnancy loss in viral infections were addressed, including alteration of trophoblast invasion and placental dysfunction, inducing excessive maternal immune response, and inducing apoptosis in the placental tissue. Viruses may cause pregnancy loss through different mechanisms and our knowledge about these mechanisms can be helpful for controlling or preventing viral infections and achieving a successful pregnancy.

Seroprevalence and Potential Risk Factors of Hepatitis E Virus among Pregnant Women in Khartoum, Sudan

Although hepatitis E virus (HEV) infection has been widely understood as a public health concern in pregnant females, it is sometimes overlooked because of unusual observations of hepatitis E-induced complications during pregnancy. The objective of this descriptive cross-sectional study was to find out how frequent Hepatitis E virus infection is in pregnant women in Sudan. Blood samples were collected from pregnant women (n = 90) attending Khartoum North Hospital from February to December 2019. The specimens were investigated for Hepatitis E virus IgG and IgM antibodies using the commercial kits based on the enzyme immunosorbent assay (ELISA) technique. Out of ninety pregnant women, 36 (40%) were found positive for IgG antibodies, and 5 (6%) were tested positive for IgM antibodies. In addition, 13 (14.5%) of the positive cases are women in their third trimester. These data showed a significant association between previous Hepatitis E virus infection and miscarriage (p <0.001). This study did not find a significant association between maternal and gestation age, education, water sources, and hepatitis E virus infection. In conclusion, there was a high percentage of HEV infections among pregnant women attending Khartoum North Hospital. This study estimates the Hepatitis E virus burden in Khartoum state, but more extensive studies are required to confirm the burden in Sudan.

Setting a Course for Preventing Hepatitis E in Low and Lower-Middle-Income Countries: A Systematic Review of Burden and Risk Factors

BACKGROUND

Hepatitis E virus (HEV) is responsible for outbreaks of acute jaundice in Africa and Asia, many of which occur among displaced people or in crisis settings. Although an efficacious vaccine for HEV has been developed, we lack key epidemiologic data needed to understand how best to use the vaccine for hepatitis E control in endemic countries.

METHODS

We conducted a systematic review of articles published on hepatitis E in low-income and lower-middle-income countries in Africa and Asia. We searched PubMed, Scopus, and Embase databases to identify articles with data on anti-HEV immunoglobulin (Ig)G seroprevalence, outbreaks of HEV, or risk factors for HEV infection, disease, or death, and all relevant data were extracted. Using these data we describe the evidence around temporal and geographical distribution of HEV transmission and burden. We estimated pooled age-specific seroprevalence and assessed the consistency in risk factor estimates.

RESULTS

We extracted data from 148 studies. Studies assessing anti-HEV IgG antibodies used 18 different commercial assays. Most cases of hepatitis E during outbreaks were not confirmed. Risk factor data suggested an increased likelihood of current or recent HEV infection and disease associated with fecal-oral transmission of HEV, as well as exposures to blood and animals.

CONCLUSIONS

Heterogeneity in diagnostic assays used and exposure and outcome assessment methods hinder public health efforts to quantify burden of disease and evaluate interventions over time and space. Prevention tools such as vaccines are available, but they require a unified global strategy for hepatitis E control to justify widespread use.

Hepatitis E in Sub Saharan Africa - A significant emerging disease

Hepatitis E is an emerging endemic disease found across the African continent, but there are clear differences in epidemiology between North Africa and countries south of the Sahara. In this systematic review, Google scholar and PubMed databases were searched for peer-reviewed articles on HEV epidemiology. Publications meeting our inclusion criteria were critically reviewed to extract consistent findings and identify knowledge gaps. Hepatitis E has been reported in 25 of the 49 countries in Sub Saharan Africa.

Mortality rates of 1–2% in the general population and ~ 20% in pregnant women. Outbreaks were closely linked to refugees and Internally Displaced Persons in camps which accounted for 50% of reported outbreaks. There was very little research and concrete evidence for sources of contamination and transmission routes. There are indications of zoonotic transmission of Hepatitis E Virus infection but further research in these fields is required.

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No data from 50% of African countries

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Outbreaks closely linked to refugee and IDP camps

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Little data on sources of HEV contamination

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Indications but little evidence of zoonotic transmission

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Low awareness amongst health professionals and general public

Seroprevalence of hepatitis E virus infection in pregnant women: a systematic review and meta-analysis

BACKGROUND

Hepatitis E virus (HEV) infection has emerged as a global public health problem that affects millions of people every year.

OBJECTIVE

Systematically review data on the prevalence of HEV IgG antibody among pregnant women around the world.

DATA SOURCES

Potentially relevant studies were identified by a search of PubMed and ScienceDirect, and by a manual search of the reference lists of identified studies.

STUDY SELECTION

Observational studies in English with no age or area restriction. Reviews, duplicate, book chapters, and other irrelevant studies were excluded.

DATA EXTRACTION

Independent searching by two investigators (TA, THM).

DATA SYNTHESIS

In the 6137 retrieved studies, 15 studies met the inclusion criteria. The studies included 7160 pregnant subjects from 11 countries. Most studies were from Africa. Of the 7160 subjects, 1182 were positive to anti-HEV IgG antibody, and only 66 were anti-HEV IgM antibody positive. The highest seroprevalence of anti-HEV IgG antibody (61.29%) was reported in Sudan and the lowest (3.41%) was reported in Italy. The overall pooled prevalence was 16.51% (95% CI: 0.10-0.23). The heterogeneity level was I ² = 98%; P≤.01.

CONCLUSION

The seroprevalence of anti-HEV IgG antibody among pregnant women differs by geographic location. Further studies are recommended to evaluate incidence, morbidity, and mortality in those areas where the disease is prevalent.

LIMITATIONS

Seroprevalence was only determined for the anti-HEV IgG antibody, which mostly indicates past infection. Heterogeneity was high among the studies in the analysis.

CONFLICT OF INTEREST

None.

Hepatitis E virus infection among pregnant women in Africa: systematic review and meta-analysis

Background

There have been a number of studies about seroprevalence of HEV among pregnant women in Africa. However, the finding of seroprevalence of HEV infection among pregnant women is variable and inconsistent. Therefore; this systematic review intended to provide the pooled seroprevalence of HEV among pregnant women in Africa.

Methods

We searched, Pub Med, Science direct, African online journals and Google scholar electronic data bases and all available references until August 30, 2018. We included cross sectional studies and cohort studies. The search was further limited studies done in African pregnant women. Statistical analysis done by using Stata (version 11) software. The overall pooled prevalence of HEV presented by using the forest plot with 95% CI. The methodological qualities of included studies were assessed using Joanna Briggs Institute Meta-Analysis of Statistics Assessment and Review Instruments.

Result

The pooled seroprevalence of HEV among pregnant women in Africa was 29.13% (95% CI 14.63–43.63). The highest seroprevalence was 84.3% in Egypt and the lowest 6.6% reported in Gabon. There was highest heterogeneity level where I² = 99.7%; P < 0.0001.The observed heterogeneity attributed to geographic location/ region, country, assay method used in each study and year of study published. Moreover, HEV seroprevalence varies between countries and within countries. The HEV infection among African pregnant women seems to have a decreasing trend over time.

Conclusion

The seroprevalence of HEV among pregnant women in Africa is high. The seroprevalence of HEV among pregnant women differ with geographic location and assay method. Therefore, it is recommended to conduct further research on commercial ELISA kit sensitivity and specificity, molecular tests, incidence, morbidity and mortality and vertical transmission of HEV from mother to infant in Africa.

Trial registration

CRD42018084963.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-4125-x) contains supplementary material, which is available to authorized users.