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.

Prevalence of antibodies to hepatitis C virus in HBsAg negative hemodialysis patients.

The prevalence of hepatitis C virus (HCV) infection was estimated in a 14-month study using anti-C100-3 antibody assay in 31 HBsAg negative patients on maintenance hemodialysis (MHD) for > or = 3 months. One and three patients respectively had ALT elevation and anti-HCV positivity at entry. During MHD (mean period of follow up 9.9 mo), 11 (35.5%) patients had, on fortnightly estimation, ALT elevation which lasted for < or = 6 months in seven patients and for > 6 months in four. Fourteen (45.2%) patients had anti-HCV (including the three positive at entry). There was no significant difference in frequency of anti-HCV positivity in patients with normal and elevated ALT (57.1% and 42.9% respectively). The number of blood transfusions and duration of MHD were similar in anti-HCV positive and anti-HCV negative patients. We conclude that our MHD patients have a high frequency of hepatitis and anti-HCV positivity, and these may not be related to blood transfusions.