Hepatitis E Virus Infection in Taiwan: Prevalence of Neutralizing Anti-HEVne Positive Serum
2001 Vol.17 NO.12
【Purpose】Hepatitis E virus infection is an important communicable disease in Asia and mainland China. The infection is characterized by the appearance of cholestatic jaundice and a high fatality among pregnant women. No outbreaks of the infection have yet been recorded in Taiwan. To ascertain the likelihood of HEV infection and its routes of transmission in Taiwan, the present study used a newly developed enzyme immunoassay to detect HEV specific neutralizing antibodies (anti-HEVne) in serum in order to assess the prevalence of hepatitis E virus infection.【Materials and Method】A series of ORF2 (open reading frame 2) with high specificity to anti-HEVne, aa578-aa607, was used as a reagent to test antibodies. The subjects tested were divided into 4 age groups: 4-5 years (200 persons, average age 4.4 years), 20-40 years (250 persons average age 32.5 years), 40-60 years 300 persons, average age 53.1 years), 60-80 years 300 persons, average age 71.9 years), and 300 pregnant women, (average age 33 years).【Results】The newly developed anti-HEVne assay as found to be very specific for the testing of HEV infection. The anti-HEV positive rates in the different age groups were, 2% (5-6 years), 8% (20-40years), 13% (40-60 years), and 11% (60-80 years). The antibody was present in about 6% of pregnant women. The findings suggested that HEV infection was higher in the 40-60 age group. According to this study, the average infection rate of the population was found to be 8.9%.【Discussion】The present study used a newly developed method to detect anti-HEV positive rates in the sera of the general population. In suspected imported cases, mainland China (56%) was considered a major source of infection. It was also speculated that the infection was spread in a low circulation/sporadic way in Taiwan. Among the groups studied, the anti-HEVne positive rate was higher in the 40-60 age group. In general, positive rates were higher in the older age groups. However, since anti-HEVne gradually disappears several years after infection, whether elderly people were more likely to be re-infected remains to be studied further.