Seroprevalence of Antibody to Hepatitis E Virus in Voluntary Blood Donors in Northern Thailand

We report the results of seroepidemiological study of hepatitis E virus (HEV) infection in 636 voluntary blood donors in four Provinces of Northern Thailand. The average seroprevalence of anti-HEV was 8.7%, which is lower than previous reports from HEV endemic areas and even in the central Thailand. No significant differences of the prevalence were found geographically and also by age and sex. Our findings suggest that Northern Thailand belongs to an intermediate prevalence group of HEV infection between non-endemic and endemic regions and the improvement of socioeconomic and hygienic status might control the spreading of HEV infection in this area

Seroepidemiological Survey of Human Immunodeficiency Virus (HIV), Hepatitis B Virus (HBV) and Hepatitis C Virus (HCV) Infections among The Hill Tribes in Northern Thailand

We report the results of seroepidemiological survey of Human immunodeficiency virus (HIV), Hepatitis B virus (HBV) and Hepatitis C virus (HCV) infections among the Karen, La-Wah and Lahu-Na, designated as the hill tribes, in northern Thailand. Some of these hill tribes are living in the remote and isolated mountain areas, settling their own communities. Anti-HIV seropositive cases were found only in the Lahu-Na (2.6%). The highest incidence of Hepatitis B surface antigen (HBs-Ag) positive was found in the Karen (13.2%), followed by the Lahu-Na (2.6%) and the La-Wah (1.7%). The highest incidence of anti-Hepatitis C virus antibody (anti-HCV) positive was found in the La-Wah (3.3%), followed by the Karen and the Lahu-Na (2.6%, respectively). Two out of nine anti-HCV positive cases were from seven and 11 year-old Karenean girls, who had no previous history of surgery, blood transfusion, intravenous medication, vaccination and dental therapy. These results suggest that HIV infections have not yet reached to the hill tribes, except the Lahu-Na. One of the possible transmission routes of HCV infection is a vertical or intrahhousehold infection among the hill tribes in northern Thailand

A High Prevalence of Hepatitis C Virus Infection Among The Human Immunodeficiency Virus Seropositive Blood Donors in Chiang Mai, Thailand

We report the results of serological survey of hepatitis C virus (HCV) and hepatitis B virus (HBV) infections among the human immunodeficiency virus (HIV) seropositive and seronegative blood donors in Chiang Mai, Thailand. Anti-HCV were positive in 17 out of 276 anti-HIV seropositive blood donors (6.2%) and six out of 844 anti-HIV seronegative blood donors (0.7%). HBs-Ag were positive in 20 out of 276 anti-HIV seropositive blood donors (7.2%) and 68 out of 844 anti-HIV seronegative blood donors (8.1%). These findings suggest that anti-HIV seropositive population belongs to a high risk group of HCV infection and there are similar transmission routes between HIV and HCV infections

Hepatitis B virus in the Lao People’s Democratic Republic: a cross sectional serosurvey in different cohorts

Background Despite hepatitis B vaccination at birth and at 6, 10 and 14 weeks of age, hepatitis B virus (HBV) infection continues to be endemic in the Lao People’s Democratic Republic (PDR). We carried out a cross-sectional serological study in infants, pre-school children, school pupils and pregnant women to determine their burden of disease, risk of infection and vaccination status. Methods A total of 2471 participants between 9 months and 46 years old were recruited from urban (Vientiane Capital, Luang Prabang), semi-urban (Boulhikhamxai and Savannakhet) and remote rural areas (Huaphan). All sera were tested for anti-HBs and anti-HBc. Sera testing positive for anti-HBc alone were further tested for the presence of HBsAg. Results A low prevalence of HBsAg (0.5%) was detected among infants from Vientiane and Luang Prabang, indicating some success of the vaccination policy. However, only 65.6% had protective anti-HBs antibodies, suggesting that vaccination coverage or responses remain sub-optimal, even in these urban populations. In pre-school children from remote areas in Huaphan, 21.2% were positive for anti-HBc antibodies, and 4.6% were for HBsAg positive, showing that a significant proportion of children in these rural regions have early exposure to HBV. In pre-school children with 3 documented HBV vaccinations, only 17.0% (15/55) were serologically protected. Among school-children from semi-urban regions of Luang Prabang, Boulhikhamxai and Savannakhet provinces, those below the age of 9 who were born after HBV vaccine introduction had anti-HBc and HBsAg prevalence of 11.7% and 4.1%, respectively. The prevalence increased to 19.4% and 7.8% of 10–14 year olds and to 27% and 10.2% of 15–19 year olds. Pregnant women from Luang Prabang and Vientiane had very high anti-HBc and HBsAg prevalence (49.5% and 8.2%), indicating high exposure and risk of onward vertical transmission to the unborn infant. Conclusions Overall, the results demonstrate a dramatic deficiency in vaccination coverage and vaccine responses and/or documentation within the regions of Lao PDR studied, which included urbanized areas with better health care access. Timely and effective hepatitis B vaccination coverage is needed in Lao PDR

タイ国北部におけるB型肝炎ウイルス，C型肝炎ウイルスおよび後天性免疫不全ウイルス感染の血清疫学的研究

A total of 1,889 voluntarily donated blood from five provinces in northern Thailand were investigated for the prevalences of hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus (HIV) infection. The average positive rates of HBs-Ag, anti-HBs, IgM anti-HBc, anti-HCV and anti-HIV were 8.7, 42.6, 0.5, 1.6 and 1.7%, respectively. The highest positive rates of HBs-Ag, anti-HBs, IgM anti-HCV and anti-HIV were found in the age group under 19 years (13.3%), 40-49 year old group (47.6%), 20-29 year old group (0.6%), 30-39 year old group (2.6%) and 20-29 year old group (2.9%), respectively. We found only two cases that were anti-HIV and HBs-Ag positive. There are no cases that were anti-HIV and IgM anti-HBc positive, and that were anti-HIV and anti-HCV positive. These results suggest that in northern Thailand, most of the HBV infections are due to vertical transmission from mother to child, although HBV infection is a major cause of viral hepatitis, HCV infection will become an important public health problem in the near future and that the prevalence of HIV infection is quite high among sexually active generations. Therefore, there is a need for more medical attention to these blood-borne virus diseases, and we strongly recommend routine blood screening for HCV in every medical institutions in northern Thailand