Prevalence of hepatitis E virus infection among people and swine in mainland China: A systematic review and meta‐analysis

Abstract

Hepatitis E virus (HEV) infection remains an important public health problem, and it is endemic primarily in developing countries. This study aimed to evaluate the seroprevalence of HEV among the general population, occupational population and swine in mainland China and its risk factors based on a systematic review and meta‐analysis. Systematic search from EMBASE, PubMed, Web of Science, Cochrane Library and several Chinese databases, such as Wanfang (WF) Data, China National Knowledge Infrastructure (CNKI), Chinese Science and Technology Periodical Database (VIP) and SINOMED, was searched from inception up to 25 April 2018. The overall seroprevalence of HEV and its corresponding 95% confidence interval (CI) as well as the correlation coefficients between different groups were estimated using stata 12.0 and r‐3.4.1 software. Potential sources of heterogeneity were explored using subgroup and sensitivity analyses. Twenty‐eight studies with 57,274 participants (including human and swine) were included. The seroprevalence of anti‐HEV immunoglobulin G (IgG) among the general population, occupational population and swine was 27.3% (95% CI: 22.4–32.2), 47.4% (95% CI: 40.1–54.8) and 66.4% (95% CI: 61.7–71.1), respectively. The overall prevalence of IgM among the general population was 1.8% (95% CI: 0.7–2.9). The odds ratio for the occupational population, as compared to the general population, was 2.63. The highest anti‐HEV IgG prevalence (59%) was observed in East China, whereas the lowest (34.8%) was noted in Northeast and North China. In the occupational population, the highest prevalence (77.0%) was observed among swine vendors. Seven studies included 30,392 participants (humans and swine); the correlation coefficient for the prevalence of anti‐HEV IgG between the professional population and adult pigs was 0.88. Sensitivity analyses showed that the stability of results was not considered significant. This research found that HEV is common in China, and contact with pork or other pig products may be an important mode of HEV transmission.

High Hepatitis E virus (HEV) Positivity Among Domestic Pigs and Risk of HEV Infection of Individuals Occupationally Exposed to Pigs and Pork Meat in Hanoi, Vietnam

“…Our previous study has provided evidence of a far higher rate of anti-HEV IgG seroprevalence in the general population (31%) compared with an earlier study indicating a seroprevalence rate of 9% only [23, 26]. In addition, the seroprevalence of anti-HEV IgG and IgM in this study is slightly higher compared with a previous study observed in general and occupational populations in different parts of China [29]. This difference is attributable to the sensitivity of the ELISA test systems applied, which differ substantially with regard to their sensitivity [30, 31].…”

Low seroprevalence of hepatitis E on Reunion island

“…Together with the scarcity of clinical cases, hallmark of a low incidence, and the low proportion of HEV IgG antibodies previously reported in blood donors [11], the low seroprevalence (raw and weighted) observed herein suggest that Reunion Island is a low endemic area for HEV transmission. Few HEV seroepidemiological studies have been conducted within general populations, as compared to studies among blood donors [[15], [16], [17]]. The figures observed in our study are in strong contrast with the seroprevalence averaging 25% in hyperendemic industrialized countries from the northern hemisphere, including France, Germany, the Netherlands and China [15,17].…”

“…Our findings confirm that males are at higher risk of HEV exposure, which has been observed both in other general populations [2,19,22] as in blood donors [11]. This might be related to occupational differences, as it has been shown that the gender effect is abrogated when the population is stratified by the occupation [17] or when the study is conducted within occupations at risk [18]. It may also be driven by ethnic/cultural differences on Reunion Island, as previously observed in the United States with the rising incidence among non-Hispanic Asian females, which has abrogated the male predominance in recent years [21].…”

“…Few HEV seroepidemiological studies have been conducted within general populations, as compared to studies among blood donors [[15], [16], [17]]. The figures observed in our study are in strong contrast with the seroprevalence averaging 25% in hyperendemic industrialized countries from the northern hemisphere, including France, Germany, the Netherlands and China [15,17]. They are more in agreement with seroprevalence below 10% reported, for instances, from Brazilian or Finnish communities [16,18].…”

Establishment of a Highly Sensitive Assay for Detection of Hepatitis E Virus-Specific Immunoglobulins

“…products and direct contact with infected animals (11)(12)(13)(14)(15). Most HEV infections are asymptomatic and self-limiting (16).…”