DETECTION OF THE TRANSMISSION OF E HEPATITIS IN COMMUNITY ANGIANG PROVINCE, VIETNAM (1995 – 1998)

 

Nguyen Thi Kim Tien *, Ha Ba Khiem*, Pham Kim Sac *,
Vu Tuyet Nhung *, Luong Chan Quang*, A.L. Corwin**

*Pasteur Institute in HoChiMinh City, ** US.NAMRU-2, Jakarta, Indonesia

 

ABSTRACT

The natural epidemic of hepatitis E virus (HEV) transmission is well documented throughout Asia. In Vietnam, the first E hepatitis outbreak was observed in An Phu district of An Giang province in 1994. To determine HEV transmission in epidemic and endemic areas, a community-based study has been realized since 1995 on acute viral hepatitis patients, school children and roaming animals in An Phu (an out break occurence in 1994) and in Tan Chau district (control district), of An Giang province in Mekong delta.

HEV was the main cause of acute viral hepatitis (24.4% in An Phu district and 16% in Tan Chau district. Most of HEV positive patients were adults (more than 20 years old) and all of them had signs of jaundice sclera and dark urine. There were more HEV positive cases in the rainy season (from June to October).

The results of a community cohort prospective study on 400 school-children in those districts showed that there were HEV prevalence in healthy student (21.6% in An Phu and 8% in Tan Chau) (p=0.003). Sero-conversion rate in An Phu and in Tan Chau after 1 year of following was 0.7% and 1.2%, and after 2 following years was 5.1% and 1.9%. Prevalence of HEV infection of family members of HEV(+) school children was 14.7%, while one of HEV(–) school children was 5.9%. Living together in the same household might be one of the risk factors for HEV transmission.

To determine whether animals in the An Phu district were naturally infected with HEV, sera collected from 25 pigs, 81 rats, 56 dogs, 93 chickens and 25 goats were examined for IgG anti HEV. Antibodies to HEV were detected in chickens (44%), pigs (36%), dogs (27%) and rats (9%) but not in any goat examined.

The transmission of HEV among patients, community and animals was detected in one district of the Mekong delta, where people mainly used water and flood occurred frequently. It warns epidemiologists and clinicians to monitor, early detect and timely intervene to prevent epidemic and outbreak of HEV in the community.