Seroprevalence of Hepatitis E Virus among Domestic Animals in Plateau State–Nigeria.

Aim: This study was undertaken to determine the epidemiology, seroprevalence and associated risk factors, of Hepatitis E virus (HEV) among domestic animals. Study Design: Cross sectional epidemiological survey. Place and Duration: The study was carried out in three geographical zones of Plateau State, over a six month period from July to December, 2012. Methodology: A total of 166 animal subjects were recruited into the study. The animals studied were made up of pigs (67), goats (43), sheep (19) and cattle (37). Information was obtained from the animal subject handlers using interviewer administered questionnaire. Blood samples were collected and analyzed for HEV antibodies (IgG and IgM) using Enzyme-linked immunosorbent assay (ELISA) technique. Data obtained were analyzed using SPSS version 17.0 statistical software. Results: Results revealed an overall prevalence of 24.1% (p<.001) with IgG and IgM accounting for 16.3% and 7.8% respectively. Goats recorded the highest prevalence with 37.2%, followed by Pigs with 32.8% and Sheep with 10.5%, but it is note-worthy that Cattle recorded 0% overall seropositivity. Statistical significant association was observed with regard to age (p=.04); animals <1 year old accounted for the highest seroprevalence (21.3%) and least among animals ≥2years old (7.7% OR 0.3; 95%CI0.1- 1.1). Seropositivity tends to decreases with increase in age. A similar trend was observed with regard to IgM seropositivity. The significant associated risk factor was; frequency of waste disposal (p<.001) (IgM, OR 39.1; 95% CI 4.9-310.4; IgG, OR 19.9; 95% CI3.9-100.7). Animals that had been vaccinated against other diseases tend to exhibit the least seropositivity compared to animal subjects with no history of any form of vaccination. Conclusion: Data suggest that HEV remains an under-recognized and significant public health issue in the study area, and prevalent among domestic animals, warranting further attention and research. Preventive public health measures should be reinforced among all communities’ particularly domestic animals and a periodic monitoring system set up for control.

Development and validation of a genotype 3 recombinant protein-based immunoassay for hepatitis E virus serology in swine

Hepatitis E virus (HEV) is classified within the family Hepeviridae, genus Hepevirus. HEV genotype 3 (Gt3) infections are endemic in pigs in Western Europe and in North and South America and cause zoonotic infections in humans. Several serological assays to detect HEV antibodies in pigs have been developed, at first mainly based on HEV genotype 1 (Gt1) antigens. To develop a sensitive HEV Gt3 ELISA, a recombinant baculovirus expression product of HEV Gt3 open reading frame-2 was produced and coated onto polystyrene ELISA plates. After incubation of porcine sera, bound HEV antibodies were detected with anti-porcine anti-IgG and anti-IgM conjugates. For primary estimation of sensitivity and specificity of the assay, sets of sera were used from pigs experimentally infected with HEV Gt3. For further validation of the assay and to set the cutoff value, a batch of 1100 pig sera was used. All pig sera were tested using the developed HEV Gt3 assay and two other serologic assays based on HEV Gt1 antigens. Since there is no gold standard available for HEV antibody testing, further validation and a definite setting of the cutoff of the developed HEV Gt3 assay were performed using a statistical approach based on Bayes' theorem. The developed and validated HEV antibody assay showed effective detection of HEV-specific antibodies. This assay can contribute to an improved detection of HEV antibodies and enable more reliable estimates of the prevalence of HEV Gt3 in swine in different regions.

Seroepidemiology of hepatitis E virus infection in 2-25-year-olds in Sari district, Islamic Republic of Iran

The seroprevalence of hepatitis E virus infection [HEV] in children and young adults was determined in a community-based survey in an area of northern Islamic Republic of Iran. Serum samples were taken from 1080 randomly selected apparently healthy 2-25-year-olds from urban and rural regions of Sari district. Anti-HEV IgG antibodies were detected in 25 individuals [2.3%]. Seroprevalence increased significantly with age from 3/255 [1.2%] in children < 10 years to 8/110 [7.3%] in those aged 20-25 years. No differences in HEV status were noted between the sexes. Earlier age at exposure to infection and a higher infection rate were found in people residing in rural areas than in urban areas

Prevalence of antibodies to hepatitis E virus among male blood donors in Tabriz, Islamic Republic of Iran

Serum samples from 399 voluntary male blood donors were tested for anti-hepatitis E virus [HEV] IgG during July and August 2004 at a blood transfusion centre in Tabriz city. The prevalence of anti-HEV IgG was 7.8% [95% CI: 5.2-10.4]. Risk factors for infection included age and a low educational level. Seroprevalence increased significantly with age, from 3.3% in subjects under 30 years of age to 37.5% in individuals 50 years and over. Illiterate individuals were at significantly higher risk for infection than educated persons. The high seropositive rate among our male blood donors is compatible with endemicity of HEV in the Islamic Republic of Iran

Role of travel as a risk factor for hepatitis E virus infection in a disease-endemic area.

BACKGROUND: We undertook epidemiologic and laboratory studies during an epidemic of acute hepatitis in Sindri town, in District Dhanbad, Bihar in 1998. METHODS: A sample survey covering 201 randomly selected houses in the town was conducted during the epidemic, and records of patients admitted to the only large hospital in this town were reviewed. We also tested serum and stool specimens from some of the affected persons for hepatitis E virus (HEV) RNA and IgM anti-HEV antibodies. RESULTS: Of the 1088 persons residing in the surveyed houses, 82 (7.54%) had developed acute hepatitis during the outbreak. Attack rate was higher among male residents than among female residents (71/604 vs. 11/484; 11.75% vs. 2.27%; relative risk [RR] 5.17 [95% confidence interval 2.77-9.65]; p<10(-6)) and was the highest in the 10-29 year age group. Hospital admission data showed similar age and gender distribution. Disease occurrence had no relation with source of drinking water (handpump 7.56% vs. municipal tap 7.53%; p=ns), or with habit of boiling (RR 1.10 [0.61-1.98]; p=ns) or filtering (RR 0.59 [0.33-1.06]; p=ns) water before drinking. Jaundice occurred more frequently among persons who had traveled outside Sindri town during the last two months than among those who had not (26.4% vs. 4.7%; RR 5.67 [3.81-8.43]; p<10(-6)); this risk persisted after correction for age (Mantel-Haenszel weighted OR 6.74 [4.12-11.01]; p<10(-6)). Men traveled more frequently than women and were more often affected. In multivariate analysis, travel and male gender were the only two independent risk factors. Data from a hospital in a neighboring large city, Dhanbad, suggested that there was an outbreak of hepatitis in that city too at the same time. Seventy-three of the 1088 study subjects had history of jaundice in the past; disease attack rate among these persons (9.6%) was similar to that among those without such history (7.5%; RR 1.31 [0.49-2.98]; p=ns). Of the 13 sera tested, 10 were positive for IgM anti-HEV. HEV RNA was detected in 9 of the 12 stool specimens and 10 of the 13 sera tested. CONCLUSIONS: The hepatitis epidemic in Sindri was caused by HEV and had several features resembling those of previous HEV epidemics. However, the occurrence of hepatitis E showed a strong relationship with history of travel, a finding not hitherto described.

Hepatitis E virus infection in selected Brazilian populations

A retrospective study on the prevalence of hepatitis E virus (HEV) infection was conducted in selected populations in Rio de Janeiro, Brazil. A total of 1,115 subjects were tested including 146 patients with acute Non-A Non-B Non-C (NANBNC) viral hepatitis, 65 hemodialysis patients, 93 blood donors, 102 intravenous drug users (IVDUs), 304 pregnant women, 145 individuals living in the rural area and 260 individuals living in the urban area. In order to characterize a favorable epidemiological set for enterically transmitted infection in the studied populations we also evaluated the prevalence of anti-HAV IgG (hepatitis A virus) antibodies. Specific antibodies to HEV (anti-HEV IgG) were detected by a commercial EIA and specific antibodies to HAV (anti-HAV IgG) were detected using a competitive "in house" EIA. We found a high prevalence of anti-HAV IgG in these populations, that could indicate some risk for infections transmitted via the fecal-oral route. The anti-HEV IgG prevalence among the different groups were: 2.1 percent in patients with acute NANBNC viral hepatitis, 6.2 percent in hemodialysis patients, 4.3 percent in blood donors, 11.8 percent in IVDUs, 1 percent in pregnant women, and 2.1 percent in individuals form the rural area. Among individuals living in the urban area we did not find a single positive serum sample. Our results demonstrated the presence of anti-HEV IgG in almost all studied populations; however, further studies are necessary to establish the real situation of HEV epidemiology in Rio de Janeiro, Brazil

Seroepidemiology of hepatitis E virus infection in Mexican subjects 1 to 29 tears of age

Background. Hepatitis E virus (HEV) infection causes an acute, self-limited hepatitis associated with high mortality in pregnant women. Community-based surverys are scarce and information on HEV infection in populations in needed. The aim of this work was to study seroprevalence to HEV in young adults and children in Mexico, using a community-based survey. Methods. Serum samples from 3,459 individuals were studied; the population included subjects from 1 to 29 years old from all regions of the country representing all socioeconomic levels, IgG anti-HEV was determined by ELISA. Results. Anti-HEV antibodies were found in 374 (10.5 percent) individuals. Seroprevalence increased with age from 1.1 percent in children young than 5 years to 14.2 percent in persons 26 to 29 years of age (p = 0.006). Risk factors for infection included living in rural communities and a low educational level. Seroprevalence was not associated with the level of regional development. Conclusions. HEV infection is endemic in Mexico. Age, type of community, and educational level were identified as risk factors for infection

Hepatitis C and hepatitis E in acute sporadic non-A non-B hepatitis in hospital patients of Delhi (India).

Non-A, non-B hepatitis (NANBH) has been considered to be the commonest cause of acute sporadic viral hepatitis in India. Serological studies (Macro ELISA) were conducted on 477 such patients from 9 hospitals of Delhi for markers of hepatitis A and acute hepatitis B (Anti-HAV-IgM,HBsAg and anti-HBc-IgM) and 49.7% of these were found to be due to NANBH. On further testing of NANBH sera it was found that both hepatitis C and hepatitis E contribute significantly to acute sporadic jaundice in Delhi, the latter more than the former.

Routes of transmission in the hepatitis E epidemic of Saharanpur.

A large waterborne epidemic of hepatitis E occurred in the city of Saharanpur (Uttar Pradesh, India) between December 1992 and April 1993. A random survey was conducted in the affected area of Saharanpur. Source of water supply, number of family members, number and characteristics of affected persons were noted. Blood, stool and water samples were collected. The incidence of hepatitis was 14% in the affected area of the city. A total of 3682 individuals were affected with the disease. Attack rate for adults was significantly higher than the children aged < 15 years (17% vs 7%; p < 0.0001). Among the adults, the attack rate was higher for males than females (23% vs 12%; p < 0.0001). The incidence of hepatitis was greater in persons using the municipal water supply (17%) as compared to hand pump (0.9%) or tubewell water (0%). There was a single peak in the epidemic. Of the 56 fresh cases, 38 (64%) occurred within two weeks, 14 within 2-4 weeks and 4 within 4-6 weeks of index cases. Serologic markers for acute hepatitis A, B and C were absent. IgM anti-HEV was positive in 20 out of 24 sera tested. Immune electron microscopy detected 27-34 nm virus-like particles (VLPs) in 2 of 8 stool specimens and in 1 of 3 water samples. The epidemic occurred due to leakage of municipal water supply pipes passing through the sewerage holes. A large waterborne epidemic of hepatitis E resulted due to contaminated water supply. VLPs were detected in water. Adults and males were commonly affected. There was no person-to-person spread.

Virus de l'hepatite E: Detection des anticorps dans une population de donneurs de sang au liban

One hundred Lebanese volunteers blood donors were tested for the qualitative detection of antibodies against hepatitis E virus [HEV] by an immunoenzymatic method. This figure allows us to confirm the presence of infection due to HEV in Lebanon. More studies on a larger panel are necessary to confirm this result. This study leads us to suspect an HEV infection in front of an acute non A, non B, non C hepatitis even if the patients have not lived in an endemic area