Seroprevalence and risk factors of recent infection with hepatitis E virus during an acute outbreak in an urban setting in Chad, 2017

Vernier, Larissa; Lenglet, Annick; Hogema, Boris M.; Moussa, Ali Mahamat; Ariti, Cono; Vollmer, Simone; Irwin, Andrea; Alfani, Prince; Sang, Sibylle; Kamau, Charity

doi:10.1186/s12879-018-3194-6

Cited by 14 publications

(13 citation statements)

References 22 publications

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“…We observed evidence of protective immunity during our analysis of immunoprevalence where participants were found to have very high antibody levels in the baseline (S1) samples which were indicative of prior exposures (9) most without complaints of the symptoms of gastrointestinal illness (15). This phenomenon of high underlying immunity in a population is not uncommon and as a recent example, was observed during an outbreak of hepatitis E virus in Chad (33).…”

Section: Discussionmentioning

confidence: 87%

Visitors to a Tropical Marine Beach Show Evidence of Immunoconversions to Multiple Waterborne Pathogens

Simmons

Eason

Curioso

et al. 2019

Front. Public Health

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Determining infections from environmental exposures, particularly from waterborne pathogens is a challenging proposition. The study design must be rigorous and account for numerous factors including study population selection, sample collection, storage, and processing, as well as data processing and analysis. These challenges are magnified when it is suspected that individuals may potentially be infected by multiple pathogens at the same time. Previous work demonstrated the effectiveness of a salivary antibody multiplex immunoassay in detecting the prevalence of immunoglobulin G (IgG) antibodies to multiple waterborne pathogens and helped identify asymptomatic norovirus infections in visitors to Boquerón Beach, Puerto Rico. In this study, we applied the immunoassay to three serially collected samples from study participants within the same population to assess immunoconversions (incident infections) to six waterborne pathogens: Helicobacter pylori, Campylobacter jejuni, Toxoplasma gondii , hepatitis A virus, and noroviruses GI. I and GII.4. Further, we examined the impact of sampling on the detection of immunoconversions by comparing the traditional immunoconversion definition based on two samples to criteria developed to capture trends in three sequential samples collected from study participants. The expansion to three samples makes it possible to capture the IgG antibody responses within the survey population to more accurately assess the frequency of immunoconversions to target pathogens. Based on the criteria developed, results showed that when only two samples from each participant were used in the analysis, 25.9% of the beachgoers immunoconverted to at least one pathogen; however, the addition of the third sample reduced immunoconversions to 6.5%. Of these incident infections, the highest levels were to noroviruses followed by T. gondii . Moreover, many individuals displayed evidence of immunoconversions to multiple pathogens. This study suggests that detection of simultaneous infections is possible, with far reaching consequences for the population. The results may lead to further studies to understand the complex interactions that occur within the body as the immune system attempts to ward off these infections. Such an approach is critical to our understanding of medically important synergistic or antagonistic interactions and may provide valuable and critical information to public health officials, water treatment personnel, and environmental managers.

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Section: Discussionmentioning

confidence: 87%

Visitors to a Tropical Marine Beach Show Evidence of Immunoconversions to Multiple Waterborne Pathogens

Simmons

Eason

Curioso

et al. 2019

Front. Public Health

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“…Given the logistical challenges of delivering three doses over a six month period, future research to better quantify the value of one and two doses of vaccine and perhaps a reduced interval between doses 2 and 3 would be valuable. Finally, it is not clear how relevant the modelling framework used here will be for community outbreaks where HEV is already endemic, such as the recent urban outbreak in Chad [ 37 ]; further work is needed to evaluate the potential impact of hepatitis E vaccination in different contexts.…”

Section: Discussionmentioning

confidence: 99%

Reactive and pre-emptive vaccination strategies to control hepatitis E infection in emergency and refugee settings: A modelling study

2018

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BackgroundHepatitis E Virus (HEV) is the leading cause of acute viral hepatitis globally. Symptomatic infection is associated with case fatality rates of ~20% in pregnant women and it is estimated to account for ~10,000 annual pregnancy-related deaths in southern Asia alone. Recently, large and well-documented outbreaks with high mortality have occurred in displaced population camps in Sudan, Uganda and South Sudan. However, the epidemiology of HEV is poorly defined, and the value of different immunisation strategies in outbreak settings uncertain. We aimed to estimate the critical epidemiological parameters for HEV and to evaluate the potential impact of both reactive vaccination (initiated in response to an epidemic) and pre-emptive vaccination.MethodsWe analysed data from one of the world's largest recorded HEV epidemics, which occurred in internally-displaced persons camps in Uganda (2007–2009), using transmission dynamic models to estimate epidemiological parameters and assess the potential impact of reactive and pre-emptive vaccination strategies.ResultsUnder baseline assumptions we estimated the basic reproduction number of HEV in three separate camps to range from 3.7 (95% Credible Interval [CrI] 2.8, 5.1) to 8.5 (5.3, 11.4). Mean latent and infectious periods were estimated to be 34 (95% CrI 28, 39) and 40 (95% CrI 23, 71) days respectively.Assuming 90% vaccine coverage, reactive two-dose vaccination of those aged 16–65 years excluding pregnant women (for whom vaccine is not licensed), if initiated after 50 reported cases, led to mean camp-specific reductions in mortality of 10 to 29%. Pre-emptive vaccination with two doses reduced mortality by 35 to 65%. Both strategies were more effective if coverage was extended to groups for whom the vaccine is not currently licensed. For example, two dose pre-emptive vaccination, if extended to include pregnant women, led to mean reductions in mortality of 66 to 82%.ConclusionsHEV has a high transmission potential in displaced population settings. Substantial reductions in mortality through vaccination are expected, even if used reactively. There is potential for greater impact if vaccine safety and effectiveness can be established in pregnant women.

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“…Data on risk factors for HEV infection (defined by IgM antibodies or RNA), disease, and death were identified in 36 studies (17,21,26,30,34,46,63,68,74,85,91,92,102,104,(108)(109)(110)112,116,129,138,139,(145)(146)(147)(148)(149)(150)(151)(152)(153)(154)(155)(156)(157)(158) from 13 countries between 1990 and 2017. One study only reported risk factors with an unknown hypothesized direction of effect and was excluded from further analysis (159).…”

Section: Risk Factorsmentioning

confidence: 99%

“…Excludes 18 seroprevalence studies with unspecified study year.Among studies that reported assay manufacturer (85%; 77/91), anti-HEV IgG antibodies were assessed using 18 different commercial assays as well as in-house assays (e.g.Walter Reed Army Institute of Research in-house assay). The most common assaysused to assess seroprevalence were in-house assays (21%)(14,34,44,47,51,53,56,60,61,70,72,79,84,91,97,100), Wantai (18%; Wantai BioPharm, Beijing, China)(20)(21)(22)(23)31,40,46,48,54,59,63,65,76,77), and Abbott (14%; (Abbott Diagnostika, Germany)(15,18,28,32,43,80,82,83,87,93,94) with the Wantai assay becoming the most commonly used assay in studies conducted in the last 5 years of the review (2013-2017).…”

mentioning

confidence: 99%

Setting a course for preventing hepatitis E in low and lower-middle-income countries: A systematic review of burden and risk factors

Koyuncu

Mapemba

Ciglenečki³

et al. 2020

Preprint

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BackgroundHepatitis E virus is responsible for outbreaks of acute jaundice in Africa and Asia, many of which occur among displaced people or in crisis settings. While 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.MethodsWe conducted a systematic review of articles published on hepatitis E in low and lower-middle-income countries (LMIC) in Africa and Asia. We searched PubMed, Scopus, and Embase databases to identify articles with data on anti-HEV IgG 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.ResultsWe 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.ConclusionHeterogeneity 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 require a unified global strategy for hepatitis E control to justify widespread use.

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Seroprevalence and risk factors of recent infection with hepatitis E virus during an acute outbreak in an urban setting in Chad, 2017

Cited by 14 publications

References 22 publications

Visitors to a Tropical Marine Beach Show Evidence of Immunoconversions to Multiple Waterborne Pathogens

Visitors to a Tropical Marine Beach Show Evidence of Immunoconversions to Multiple Waterborne Pathogens

Reactive and pre-emptive vaccination strategies to control hepatitis E infection in emergency and refugee settings: A modelling study

Setting a course for preventing hepatitis E in low and lower-middle-income countries: A systematic review of burden and risk factors

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