Status of hepatitis B infection - a decade after hepatitis B vaccination of susceptible Nicobarese, an indigenous tribe of Andaman & Nicobar (A&N) islands with high hepatitis B endemicity.

BACKGROUND & OBJECTIVES: Andaman and Nicobar Islands of India, home to six primitive tribes, constituting about 10 per cent of the total population of these Islands have been detected with high endemicity of hepatitis B infection. During 2000, a total of 936 individuals ≤ 45 yr, negative for hepatitis B surface antigen (HBsAg) and antibody anti-HBs were vaccinated with three doses of a recombinant DNA hepatitis B vaccine in two villages of Car Nicobar Islands. The present study was undertaken to evaluate the impact of the hepatitis B vaccination with respect to the persistence of antibodies and incidence of new infections, prevalence of surface gene mutations among the Nicobarese community in the two villages ten years after hepatitis B vaccination. METHODS: Follow up samples were collected from 211 individuals who had received three doses of vaccine ten years back and from a control group of 515 non-vaccinated individuals. The HBsAg, anti-HBs and anti-HBc assay results were compared among vaccinated and non-vaccinated groups. HBV DNA was extracted and sequenced from all the samples for detection of mutation. Genotyping and serotyping of the viruses were performed. RESULTS: The results showed that 85.3 per cent of the vaccinated persons retained protective level of antibodies and among the non-vaccinated individuals, 54.2 per cent showed presence of anti-HBs indicating an exposure to the infection. The overall HBsAg positivity among the studies Nicobarese individuals was reduced to 7.4 per cent after 10 years of vaccination. Anti-HBc was positive in 60.6 and 57 per cent among the vaccinated and non-vaccinated individuals, respectively. Overall breakthrough infection of 8.5 per cent was detected among the vaccinated individuals. The predominant genotype and serotype circulating among these tribal populations were D and ayw3, respectively. INTERPRETATION & CONCLUSIONS: The results of this study showed an overall reduction in the pool of HBsAg carriers because of the vaccination which helped in reducing the HBsAg carrier rate among the non-vaccinated also, probably due to an increase in herd immunity and reduction in the source of infection. Further studies need to be done to evaluate long term benefits of hepatitis B vaccination among these tribes.

Impact of hepatitis B immunization among the Nicobarese tribe--antibody titres & seroprotection five years after vaccination.

BACKGROUND & OBJECTIVES: A total of 237 Nicobarese subjects who had received hepatitis B vaccination as part of mass vaccination project during 2000-2001 were screened for anti-HBsAg titres by quantitative ELISA five years after vaccination. METHODS: Anti-HBsAg antibody was estimated using quantitative ELISA. Proportion of the subjects with protective levels of antibody and geometric mean antibody titres were calculated. RESULTS: Among the 237 study subjects, 213 had received three doses of vaccine, 17 had received two doses and seven had received one dose. The geometric mean titres of anti-HBs antibodies were 201.7, 31.9 and 23.1 mIU/ml among those who received three, two and one dose of vaccine, respectively. Among those who received three doses of vaccination, 85.9 per cent had anti-HBs antibody levels of 10 mIU/ml or more, indicating seroprotection. The difference in the seroprotection rates among those who received three doses of vaccination (85.9%) and those who received less than three doses (58.3%) was significant. Seroprotection rates one month after the first, second and third dose of vaccination were 49.1, 86.9 and 96.7 per cent, respectively. It then declined to 89 per cent by the end of the second year and to 85.5 per cent by the end of the third year, but there was no decline thereafter. INTERPRETATION & CONCLUSIONS: Seroprotection rate reached at the maximum one month after the third dose of HBV vaccine. Although about 15 per cent of the vaccinated persons lost seroprotection by the end of the third year, no further loss in seroprotection was observed between the third year and the fifth year.

Prevalence of HIV seropositivity among surgical patients in a tertiary care hospital.

The incidence of HIV infection has increased tremendously over the last few years. The new 2006 estimates released by the National AIDS Control Organisation (NACO), supported by UNAIDS and WHO, indicate that national adult HIV prevalence in India is approximately 0.36%, which corresponds to an estimated 2 million to 3.1 million people living with HIV in this country. The positive rate of HIV tested persons has shown a rising trend. So, a study was conducted on patients attending the surgery department for different operative procedures and 13 patients were HIV reactive out of 1697 patients tested. Routine HIV testing is usually not carried out at most centres and the medical fraternity is constantly exposed to the risk of HIV infection which can have wide-ranging implications in a health professional's life. HIV testing should be insisted on every patient before undertaking any surgical procedure routinely.

Assessment of injection-related practices in a tribal community of Andaman and Nicobar Islands, India.

A survey to assess injection related practices carried out among the Nicobarese, a mongoloid tribe of Andaman and Nicobar Islands, India. The survey was carried out using the rapid assessment and response guide of Safe Injection Global Network of the World Health Organization and included review of randomly selected prescriptions of patients attending outpatient clinic of district hospital, interview and observation of injection providers in the district hospital and sub-centres and interview of the general population. The findings of the survey showed that 18.8% of prescriptions included at least one injection. The per capita injection rate was 3 per year. Majority of injections were administered with disposable syringe and needle and in hospital setting. All the injection providers were aware about possibility of HIV transmission through unsafe injections. However, the awareness among the general population was low. More than half of the individuals had preference to injections. It is suggested that remedial measures, such as education of prescribers to reduce the number of injections to a bare minimum, maintaining regular supply of disposable injection equipment, provision of adequate sharps containers with safe disposal facilities and community education be undertaken to avoid future spread of blood-borne pathogens.

Effect of herbo-mineral formulation EHb in experimental anaemia in rodents.

EHb-a herbo-mineral formulations of iron (ferrous form) produced a significantly higher and dose dependent increase in the haemoglobin level, as compared to Fefol (a non-complex-chelated iron preparation). Also, EHb did not produce any overt toxicity or gastric irritation at these dose levels. The results suggest that EHb can be of a better choice in the treatment of anaemia than any other commercially available chelated iron preparations.