Methods. This cross-sectional study was conducted in Baseco in Tondo, Manila, an urban community where enterically-transmitted infections such as salmonellosis, amoebiasis and Hepatitis A are common. After obtaining informed consent, serum samples were collected from both male and female residents of Baseco aged 19 and above (n = 408). Coded serum specimens were tested for HEV IgG and IgM antibodies using the AMRAD Biotech HEV IgG and IgM ELISA, respectively. A questionnaire was also administered to determine the socio-economic status, waste disposal practices and source of drinking water of the residents.
Results. HEV-IgG Serology. Four hundred-eight residents out of the total population of 872 residents (46.79 percent) aged 19 years old and above were recruited to the study. Of the 408 residents, 235 were female (57.60 percent) and 173 (42.40 percent) were male. Overall seropositivity for HEV-IgG was 10.78 percent (44/408 residents) with the highest prevalence of 17.31 percent in the 60 age group. The difference in prevalence of HEV-IgG among the age groups, was, however, not statistically significant. More males (24/44 or 54.55 percent) were HEV-IgG positive than females (20/44 or 45.45 percent); this difference in over-all sex-specific prevalence was, however, not statistically significant. The overall HEV-IgG prevalence among the males is 13.87 percent with the peak prevalence of 30.77 percent in the 60 years age group. On the other hand, the overall HEV-IgG prevalence among the females is lower compared to the males at 8.50 percent with the peak prevalence of 22.22 percent among the 19 year olds. Among HEV-IgG positive females, 85 percent (17/20) were in the age range of 19-49 years old and are therefore of child-bearing age with 2 women actually pregnant during the cross-sectional survey.
Drinking boiled water. Questionnaire data was analyzed for correlation of HEV-IgG positivity status with socio-economic status, crowding, water supply and mode of sanitation in the community. Only one questionnaire item was statistically significant and correlated with HEV-IgG positivity. This item was whether drinking water was boiled. The data showed that a total of 57.36 percent drank relatively clean water (boiled or store-bought purified water) while 42.64 percent never boiled their drinking water.
Jaundice and HEV-IgG positivity. Six out of the 44 HEV-IgG positive (13.64 percent) had a positive history of jaundice of unspecified causes. This was not significantly different from the positive history of jaundice in 11.94 percent (43/360) HEV-IgG negative cases.
Conclusions. Residents from this urban community had previous exposure to HEV as evidenced by the prevalence of HEV-IgG among the 19 year olds and above following a cross-sectional survey of serum Data from this study may be used as basis for the development of community-based strategies for the control and prevention of HEV infection.
The magnitude of occurrence of HEV in the Philippines is not known. Neither has there been any reported outbreak of HEV infection in communities. This community-based study is therefore important since it establishes for the first time the seroprevalence of antibodies (both IgG and IgM) to HEV in an urban community in Manila using a recently available enzymeimmunoassay based on recombinant antigens.