JOURNAL OF SCIENCE, Hue University, N 0 61, 2010 STUDY ON THE PREVALENCE OF HBsAg SEROPOSITIVITY IN PEOPLE IN THUA THIEN HUE PROVINCE Ngo Viet Loc College of Medicine and Pharmacy, Hu
Trang 1JOURNAL OF SCIENCE, Hue University, N 0 61, 2010
STUDY ON THE PREVALENCE OF HBsAg SEROPOSITIVITY
IN PEOPLE IN THUA THIEN HUE PROVINCE
Ngo Viet Loc College of Medicine and Pharmacy, Hue University
SUMMARY
Hepatitis B infection is caused by the hepatitis B virus (HBV). About 400 million people across the world are chronically infected by the hepatitis B virus Hepatitis B is a leading cause
of chronic hepatitis, cirrhosis, and hepatocellular carcinoma, accounting for 1 million deaths annually In Asia, the rate of hepatitis B surface antigen (HBsAg) carriage in the general population ranges from 2% to 20% The aim of this study were to determine the percentage of
positive hepatitis B surface antigen of people aged 6 and over in Thua Thien Hue Province Methodology: A cross sectional descriptive study was conducted from 2006 to 2008, including
2,525 people aged 6 years and over who were living in four ecological areas of Thua Thien Hue Province: mountainous, low land, coastal and Hue city (urban) These people were detected the
hepatitis B surface antigen (HBsAg) by enzyme immunoassay and interviewed by questionnaire Results: The overall prevalence of the HBsAg positive was 16.36%, analysis of sex in the group
of HBsAg positive: the prevalence of HBsAg positive in females was higher than in males (21.14% and 12.05%), HBsAg positive and age groups: the HBsAg positive prevalence was the highest in the age groups of 20 - 19 (22.34%) and 31 - 40 (20.17%) HBsAg positive and occupation: the highest prevalence of HBsAg positive (26.43%) was found among manual workers HBsAg positive and ecological areas: The prevalence of HBsAg positive in coastal
area was the highest (20.15%) Conclusion: The prevalence of the HBsAg positive of people
aged 6 and over in Thua Thien Hue province was 16.36% Accordingly, public measures to control HBV infection are needed
Key word: Infection of HBV
1 Introduction
Hepatitis B virus (HBV) infection is a global public health problem and it has been estimated by the World Health Organization (WHO) that 2,000 million people (one
Hepatitis B infection is caused by the hepatitis B virus (HBV) Of these, about
region Of the carriers, 25% are at risk of serious illness and eventual death from
Trang 2cirrhosis or hepato-cellular carcinoma (HCC)
The prevalence of chronic HBV infection is endemic in many countries of Asia and Africa and it has been estimated as 2.8% in developing countries and 7.6% in developing countries HBV infection in the Asia-Pacific region is among the highest in the world, and chronic HBV infection in most of the countries of the Asia-Pacific region is high (>10%
The prevalence is low (<1%) in Australia and New Zealand, 1-5% in Japan, Singapore, India and Thailand, 6-10% in Bangladesh, Indonesia and northern China and highest (>10%) in Taiwan, southern China, Korea, Philippines, Melanesia, Micronesia and Polynesia
Vietnam is also regarded as a country with a high endemicity of HBV infection The study of Vietnam National Institute of Hematology and Blood transfusion has recorded a HBsAg prevalence of 11.1% in blood donors Two other studies in Ho Chi Minh City and Ha Noi have given the prevalence of HBsAg been 14.8% and 14.4%
In Thua Thien Hue Province, Nguyen Ngoc Minh et al found the HBsAg prevalence of 13.57% in blood donors Pham Van Linh and Tran Thi Minh Diem have gieven the rate of 16.8% in 1,478 aged 3 years and over
Health authorities in Vietnam have taken various steps to control and manage HBV infection It has been regarded as a priority disease in the National Health Plans
The purpose of this study was to determine the seroprevalence of hepatitis B virus surface antigen (HBsAg) in people aged 6 years old and over, in Thua Thien Hue Province
2 Methods
The descriptive, cross-sectional study from 2006 to January 2008 was carried out on 2,525 people aged 6 years and over in Thua Thien Hue which is located in central zone of Vietnam
The study population was randomly selected using stratified sampling to size The subject matter of ecology of Thua Thien Hue province is normally divided into four areas: mountainous, low land, coastal and Hue city (urban) Each ecological area was randomly selected two communes or two wards The study population of each commune or ward was selected using simple random sampling
These people were detected the hepatitis B virus surface antigen (HBsAg) by enzyme immunoassay Information was collected from them by interviewing and asking
to fill up the questionnaire given to them at the time of collecting blood samples Information included general data like sex, age, occupation etc
Trang 3the groups A p-value of < 0.05 was considered significant
3 Results
A total of 2,525 people aged ≥ 6 years old were tested for HBsAg This number was made up of 1,197 males and 1,328 females Of these, 413 people were positive for HBsAg, giving an overall prevalence of 16.36% It was shown in table 1
Table 1 The overall prevalence of the HBsAg positive
Table 2 Sex-wise distribution of HBsAg positive cases
HBsAg seroprevalence rate among the males was 21.14%, while it was 12.05% among the females The difference in positivity between males and females was statistically significant (p < 0.05)
Table 3 Age-wise distribution of HBsAg positive cases
Age groups (years) No of subjects HBsAg positive
Table 3 showed the HBsAg positive prevalence was the highest in the age groups of 20 - 19 (22.34%) and 31 - 40 (20.17%), while it was 10.18% and 10% in the 6 -14 and the ≥ 60 years age This difference was statistically significant (p < 0.05)
Trang 4Table 4 Occupational distribution of HBsAg positive cases
The highest prevalence of HBsAg positive (26.43%) was found among manual workers This difference was statistically significant (p < 0.05)
Table 5 Ecological areas distribution of HBsAg positive cases
Ecological areas No of subjects HBsAg positive
In relation to ecological areas, the coastal area had the highest rate of HBsAg positive (20, 15%) followed by the areas where were mountainous (16, 90%) and low land (16.14%), while Hue City (urban) had 14.07% The difference in positivity between four areas was statistically significant (p < 0.05)
4 Discussion
Our study showed HBsAg prevalence rate of 16.36% among 2,525 people aged
≥ 6 years old were tested for HBsAg
higher than that observed in some of the previous studies in different parts of Vietnam
did not participate to donate blood in the study Pham Hoang Phiet (2005) obtained a lower HBsAg prevalence of 4.8% in people that were tested for HBsAg before vaccination This may be due to the fact that most of the participants in the present
Trang 5Seropositivity was significantly more in males (21.14%) than females (12.05%) This difference was statistically significant (p-value <0.001) In earlier studies such as Tran Thi Chinh et al (1993), Hoang Thuy Long (1995) and Pham Van Linh and Tran Thi Minh Diem (2006) also have made similar observations This might be due to the fact that males have many risk factors of HBV infection
Age distribution showed that the two highest rates of HBsAg positivity (22.34% and 20.17%) were in the age groups of 20 - 29 and 30 - 39 This was similar to the findings of Dao Dinh Duc et al (1997) and Pham Van Linh and Tran Thi Minh Diem (2006) The lowest rate of HBsAg positivity (10%) was in ≥ 60 years age group The explanation for this observation was that the low number of subjects studied in the older age group
HBsAg positivity (26, 43%) The results of our study were similar to that recorded in previous study of Pham Van Linh and Tran Thi Minh Diem This might be due to the fact that most of manual workers had not been vaccinated against hepatitis-B yet Another reason is that their knowledge of prevention of HBV infection was still not good
Among four ecological areas studied, coastal area had the highest HBsAg prevalence (20.15%) This is similar to the findings of Pham Van Linh and Tran Thi
advantageous yet Means of transport here is mainly by boats It is difficult for people to take them to reach the places where have vaccination Moreover, people in this area did not pay attention to knowledge of HBV
5 Conclusion
The overall prevalence of the HBsAg positive in people aged 6 years and over in Thua Thien Hue province was 16.36% The prevalence of HBsAg positive in females was higher than in males (21.14% and 12.05%) The HBsAg positive prevalence was the highest in the age groups of 20 - 19 (22.34%) and 31 - 40 (20.17%) The highest prevalence of HBsAg positive (26.43%) was found among manual workers The prevalence of HBsAg positive in coastal area was the highest (20.15%)
Therefore, hepatitis B vaccination should be incorporated into routine childhood immunization programmers for all regions in Vietnam because hepatitis B vaccination remains the most important aspect of prevention of hepatitis B virus infection
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