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Original Articles

Indian Pediatrics 2000;37: 149-152

Community studies on prevalence of HBsAg in two urban populations of southern india

Jagvir Singh, Rajesh Bhatia, Shashi Khare, S.K. Patnaik*, Shyamal Biswas**, Sohan Lal** D.C. Jain and Jotna Sokhey

From the National Institute of Communicable Diseases, 22 Shamnath Marg, Delhi 110 054, India; *National Institute of Communicable Diseases, Regional Filaria Training and Research Center, Weavers Colony, Rajahmundry 533 105, Andhra Pradesh, India; and **National Institute of Communicable Diseases, Plague Surveillance Unit, 8 Bellary Road, Bangalore 560 003, Karnataka, India.
Reprint requests: Dr. Jagvir Singh, Deputy Director, National Institute of Communicable Diseases, 22 Shamnath Marg, Delhi 110 054, India.

Manuscript received: July 19, 1999; Initial review completed: August 6, 1999; Revision accepted: August 24, 1999.

Objective: To find out prevalence of HBsAg in general population, especially in under-five children. Setting: Bangalore and Rajahmundry towns in southern India. Methods: Localities were chosen as the sampling units in each town. About 10-20 households were randomly selected from each locality. Only the youngest but apparently healthy person present in the household was interviewed for age, sex and history of jaundice any time in life. Mothers were interviewed to collect data for children below 15 years of age. Blood samples were collected from these persons on filter paper strips (18-mm diameter disc, Whatman filter paper No. 3) by finger prick method. The samples were tested for HBsAg by Micro ELISA (Ortho-Clinical Diagnostics). Results: Overall, 3.3% (95% CI, 2.0-4.5) of 737 persons in Rajahmundry and 4.2% (95% CI, 2.8-5.5) of 816 persons in Bangalore were found carriers of HBsAg. Age-specific or sex specific carrier rates were similar in Rajahmundry as well as in Bangalore. Most of the carriers (96%) denied having jaundice ever in life. Conclusions: The results from this community based study are in agreement with the historical data from hospital based studies that about 3-5% of persons may be carriers of HBsAg and that the pool of chronic carriers of hepatitis B virus in India is built up in childhood and is then maintained in older children and adults. The results highlight the need of completing hepatitis B immunization during the infancy.

Key words: Chronic hepatitis B carriers, HBsAg carriers, Filter-paper method.


A large number of studies on antenatal mothers and voluntary blood donors have found that about 3-5% of adults may be chronic carriers of HBsAg in India (NICD unpublished review on prevalence of HBsAg in India). In contrast, only a few studies have estimated the prevalence of HBsAg in non-institutional healthy persons (Table I)(1-8).

Table I__Historical Data on Prevalence of HBsAg in Non-Institutional Healthy Persons in India.
Year Place of study  Age group (years) Test No. tested for HBsAg % +ve for HBsAg Reference
1963 Arunachal Pradesh  10-50 RPHA 296 8.5 1
1972-74 Chandigarh 0.5-14 IEOP 238 1.3 2
1974-76 Uttar Pradesh Adults Adults CIEP 846 1.2 3
1975 Ladakh Not mentioned CIEP 144 9.7 4
1980 Pune All Ages RIA 700 5.9 5
1985-89 Calcutta, West Bengal Not mentioned ELISA 101 3.0 not mentioned
1990 Madhya Pradesh (tribal population) 6-18 RPHA 1314 15.7 6
1991  Many states 0-4 ELISA 982 2.1 7
1992 Rajasthan Not mentioned RPHA 1015 7.7 8
1990-92 Dadar & N.H All Ages perhaps ELISA 96 2.8 not mentioned

*Data presented during meetings on Viral Hepatitis Surveillance Programme, NICD, Delhi.

RPHA = Reversed passive hemagglutination; IEOP = Immunoelectro-osmophoresis;

CIEP = Counter immuno electrophoresis;

RIA = Radio-immunoassay;

ELISA = Enzyme linked immunosorbent assay.

 

Moreover, these studies were plagued with the problem of sampling, and not all of them used the most sensitive tests for detection of HBsAg. Nevertheless, HBsAg prevalence rates were significantly higher in areas where tribal population was sampled. Keeping in view that community data on prevalence of HBsAg that are critical to define immunization strategies against hepatitis B virus infection are scarce, we planned the present study in urban population of Rajahmundry and Bangalore towns in south India. The results are presented in this report.

Subject and Methods

In 1997-98, a multi-centric study was carried out by the National Institute of Communicable Diseases (NICD), Delhi in Rajahmundry and Bangalore towns to understand the epidemio-logy of viral hepatitis in community settings. Localities were chosen as the sampling units in each town, and all the population in selected localities were surveyed. More than 70,000 population was surveyed in each town. The paramedics went from house to house to enquire about the cases of jaundice. Data on age and sex of all the family members were also collected and entered in the registers. These registers were used as sampling frame for the present study. About 10-20 households were selected from each locality for the present study. Only the youngest but apparently healthy person present in the household was included. Thus, there was a positive bias for selection of younger children. All the selected subjects were interviewed for their age, sex and history of jaundice any time in life. Mothers were interviewed to collect data for children below 15 years of age. Blood samples were collected from all the selected persons on filter paper strips (18 mm diameter disc, Whatman filter paper No. 3) by finger prick method. Informed oral consent was obtained from all the subjects/mothers before collecting the samples. The samples were dried in the air and stored in a plastic bag at room temperature. All the samples were transported to the laboratories of NICD at Delhi at room temperature but stored at-20° C till tested for HBsAg.

Filter paper discs soaked with blood were cut and put in half test tube containing 0.5 ml of phosphate buffer saline. They were left at room temperature for one hour. After that, discs were removed by squeezer and forceps and squeezed on the side wall of the test tube to eluate as much serum as possible. From one disc, about 0.2 ml of eluate was obtained which was tested for HBsAg by standard procedure using Micro ELISA test kit (Ortho-Clinical Diagnostic System, Johnson and Johnson Ltd., Mumbai). Samples tested positive for HBsAg were repeated before labeling them positive for HBsAg.

Results

Overall, 3.3% (95% CI, 2.0-4.5) of 737 persons in Rajahmundry and 4.2% (95% CI, 2.8-5.5) of 816 persons in Bangalore were found positive for HBsAg (Table II). Age-specific or sex-specific HBsAg carrier rates were similar in Rajahmundry as well as in Bangalore (p>0.05). About 96% (23/24) of the carriers in Rajahmundry denied having jaundice any time in the life. A 9-year-old child had jaundice at the age of 2 years. Such histories were not collected in Bangalore.

Table II__Age and Sex Specific HBsAg Carrier Rates in Urban Rajahmundry and Bangalore
Rajahmundry Bangalore
  No. of persons tested  No. (%) positive for HBsAg No. of persons tested  No. (%) positive for HBsAg
Age group (years)        
0-4  220 5 (2.3) 400 20 (5.0)
5-9 122 5 (4.1) 163 9 (5.5)
10-14 97 2 (2.1) 92 2 (2.2)
15-29 111 6 (5.4) 79 2 (2.5)
20-39 171 5 (2.9) 73 1 (1.4 )
40+ 16 1 (6.3) 9 0 (0)
sex        
Male 309 10 (3.2) 397 16 (4.0)
Female 428 14 (3.3) 419 18 (4.3)
Total 737 24 (3.3) 816 34 (4.2)

Discussion

HBsAg carrier rate of 3.3% (95% CI, 2.0-4.5) and 4.2% (95% CI, 2.8-5.5) in the general population of Rajahmundry and Bangalore respectively indicated that hepatitis B virus infection is widespread in these areas. The results are also in agreement with a large number of hospital based studies on antenatal mothers and voluntary blood donors that about 3-5% of adults from different parts of the country may be carriers of HBsAg. About 3.4% (15/444) of healthy adults (15 years and above) in the present study were positive for HBsAg.

Most of the carriers (23/24 = 96%) in Rajahmundry denied any history of jaundice in the past; the presence of jaundice in the only person may or may not be due to hepatitis B. Thus the results support the previous observa-tions that most of the persons become HBsAg carriers after asymptomatic infection or after a mild disease which do not produce clinical jaundice(9).

Although the need of introducing the hepatitis B vaccine under the immunization programme is well recognized, timing of the first dose remains to be decided. If the perinatal transmission contributes a significant proportion of infections, the first dose of vaccine should be given as soon after birth as poosible. When the transmission is mainly horizontal, the first dose of hepatitis B vaccine may be given later with other vaccines, for example, with the first dose of DPT vaccine(10). Unfortunately, our data were not helpful in making such decision because not many newborns were available for testing of HBsAg. Nevertheless, the data indicated that the pool of chronic carriers of hepatitis B virus is built up in the childhood or may be even during infancy - 6.3% (1/16) of infants in Rajahmundry and 7.3% (2/41) in Bangalore were found carriers of HBsAg. The results thus highlight the importance of completing hepatitis B immunization during the infancy itself.

Finally, the blood samples were collected on filter papers. It has been found a suitable method for detecting HBsAg carriers and most anti-HBs positive individuals, but not anti-HBc positive individuals(11). We also found in a small study in the laboratory that this technique is suitable for detecting HBsAg carriers (data not shown). We believe that community studies to find the prevalence of HBsAg in general population were not carried out in India earlier because the healthy individuals, especially children, do not agree to provide blood samples by vene-puncture. Collection of blood samples on filter paper may provide a convenient and suitable method for future community based studies in India.

References

1. Prasad R, Rodrigues FM, Dhorje SP, Ramamoorthy CL. Prevalence and subtypes of hepatitis B surface antigen in the tribal population of Arunachal Pradesh, India. Indian J Med Res 1983; 78: 300-306.

2. Pal SR, Chitkara NL, Choudhury S, Dutta DV, Deodhar SD, Chhuttani PN. Hepatitis B virus infection in northern India. Bull WHO 1974; 51: 13-17.

3. Mittal VN, Gupta OP, Nigam DK, Saxena PC, Kumar S. Pattern of hepatitis B antigen contact and carrier state in northern India. J Indian Med Assoc 1980; 74: 105-107.

4. Dutta RN, Sen S. A study of Australia antigen, cold antibodies and ABO blood group frequencies in Ladakhies. Indian J Med Res 1975; 63: 1635-1640.

5. Sobeslavsky O. Prevalence of markers of hepatitis B virus infection in various countries: A WHO collaborative study. Bull WHO 1980; 58: 621-628.

6. Joshi SH, Gorakshakar AC, Mukherjee M, Rao VR, Sathe MS, Anabhavane SM, et al. Prevalence of HBsAg carriers amogn some tribes of Madhya Pradesh. Indian J Med Res 1990; 91: 340-343.

7. Tandon BN, Irshad M, Raju M, Mathur GP, Rao MN. Prevalence of HBsAg and anti-HBs in children and strategy suggested for immunization in India. Indian J Med Res 1991; 93: 337-339.

8. Jain RC. Prevalence of HBsAg among tribal population of Udaipur district in southern Rajasthan. Indian J Med Microbiol 1992; 10: 257-259.

9. Hsu HH, Feinstone SM, Hoofnagle JH. Acute viral hepatitis. In: Mandell, Douglas and Bennett's Principles and Practice of Infectious Diseases, vol. 1, 4th edn. Eds. Mandell GL, Bennett JE, Dolin R. New York, Churchill Livingstone, 1995; pp 1136-1153.

10. Expanded Programme on Immunization. Hepatitis B vaccine-making global progress. EPI Update, October 1996.

11. Zoulek G, Burger P, Deinhardt F. Markers of hepatitis viruses A and B: Direct comparison between whole serum and blood spotted on filter-paper. Bull WHO 1985; 63: 935-939.

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