RÉSUMÉ
Background: Hypertension, a significant risk factor for various non-communicable diseases, poses a preventable threat to mortality and disease burden. However, there remains a lack of data on hypertension within Indian tribes, particularly those residing in impoverished areas. Determining the prevalence of hypertension and identifying associated risk factors among the Nicobarese tribes. A cross-sectional survey was conducted, involving 2600 tribal individuals aged 18 years and above from ten randomly selected villages on Car Nicobar Island. Methods: A structured questionnaire was utilized to gather data on blood pressure (BP), anthropometric measurements, and detailed participant characteristics. Prevalence of hypertension was determined and analyzed in relation to various identified risk factors using chi-square, Karl Pearson coefficient of correlation, and generalized linear models. Prevalence ratio and adjusted risk ratio calculated, along with their corresponding confidence intervals. Results: Prevalence of hypertension was 57.9%. Several factors, including age, male gender, illiteracy, diabetes, smoking, alcohol consumption, and higher body mass index (BMI), were significantly associated with hypertension. Systolic and diastolic BP levels increased significantly with age, socio-economic scores, BMI, and weight. Conclusions: The prevalence of hypertension among the Nicobarese tribes is significantly higher compared to the general population. Adapting preventive strategies based on an understanding of the tribe's specific culture and lifestyle is important for controlling hypertension. However, it is also crucial to consider genetic and environmental influences that may contribute to the high prevalence of hypertension in this tribe.
RÉSUMÉ
Background & objectives: Tribal people often depend on herbal medicines and the traditional knowledge practitioners (TKPs) serve as their healthcare service providers. This study was an attempt to document the use of medicinal plants by the Nicobarese of Nancowry group of Islands. Methods: Field survey was conducted in all the five inhabited Islands of the Nancowry group of Islands. All the TKPs were interviewed with a questionnaire-guided ethnomedicinal survey protocol. Voucher specimens of all the cited plants (botanic species) were collected and a community biodiversity register of Nicobarese of Nancowry was prepared. Results: A total of 77 TKPs were identified, who together were using 132 medicinal plant species belonging to 113 genera and 62 families. The TKPs were treating a total of 43 ailments. Seven endemic and three rare plant species were recorded. The most common plant part used was leaves. Remedies were usually prepared using water as the excipient. Routes for administration of medicinal plant preparations were oral, topical and others. The information collected from the TKPs were collated in the form of Community Biodiversity Registers. Interpretation & conclusions: The present survey shows that the medicinal plants play a pivotal role in the healthcare of the Nicobarese tribe of Nancowry group of Islands. Efforts to document the medicinal plant species and the formulations used by them are necessary to prevent the loss of this precious knowledge.
RÉSUMÉ
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.
RÉSUMÉ
In India diurnally subperiodic filariasis (DspWB) is prevalent only in the Nicobar district of Andaman and Nicobar Islands. Studies undertaken at different points of time indicate that this form of filariasis is restricted to a small region in Nancowry group of islands where it is transmitted by mosquito Downsiomyia nivea, a day biting mosquito. Studies on prevalence, distribution, and assessment of endemicity status, vector incrimination, bioecology, host seeking behaviour, population dynamics of the vector, transmission dynamics and clinical epidemiology indicate the prevalence and persistence of this infection in the Nancowry group of islands with perennial transmission. There was no control programme in these islands, until the National programme to eliminate filariasis was launched in 2004. Eight rounds of annual mass drug administration (MDA) with diethyl carbamazine (DEC) + albendazole have been completed. Despite this, microfilaria prevalence remains at above one per cent, the level identified for initiating transmission assessment survey to decide on continuation of MDA further. This necessitates adjunct measures to the ongoing MDA programme in these islands. The vector control options could be an adjunct measure, but the vector is a forest dweller with a unique bio-ecology, therefore, not a technically feasible option. Use of DEC fortified salt for six months to one year could hasten the process of elimination. Although administration of DEC-fortified salt is simple, rapid, safe, and cost-effective, challenges are to be tackled for evolving operationally realistic strategy. Such a strategy requires commitment of all sections of the society, a distribution mechanism that ensures the use of DEC-fortified salt in the Nancowry islands. Here we discuss the plan of action to serve the indigenous communities and operationalizing DEC fortified salt strategy through an inter-sectoral approach involving multiple stakeholders.
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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.
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Background & objectives: There are no composite estimates on prevalence of hypertension among indigenous tribes in India. The present study was carried out to estimate the prevalence of hypertension, its association with determinants, and to assess the hypertension related behaviour of the Nicobarese aborigines. Methods: This cross-sectional survey was carried during 2007 and 2009. Subjects were chosen by two stage design. Total 975 subjects of 1270 (response rate of 76.8%) were investigated (M: 43.5%; F: 56.5%). The data were collected by history, clinical examination (blood pressure), and examination (weight and height). The association of hypertension with age, education, tobacco, alcohol consumption and their dependency status (KF score, QF value, and AUDIT score) and nutritional status was estimated by bivariate regression analysis; the increasing trend in the prevalence of hypertension with increasing age and decreasing educational status was analysed by χ2 for linear trend. Significant variables in bivariate regression analysis (age, education, alcohol consumption status, and nutritional status) were subjected to multiple logistic regression analysis (MLR). Results: The prevalence of hypertension was 50.5 per cent [95% CI 46.1-54.9 (M: 50.7%; F: 50.3%)]. The prevalence of tobacco, alcohol consumption, and overweight/obesity was 88, 54, and 37 per cent respectively. The bivariate analysis has shown association between hypertension and age, education subcategories, alcohol consumption, and overweight/obesity (P<0.05). The increasing trend in the prevalence of hypertension with increasing age (χ2 for linear trend=95.88, P< 0.001) and decreasing educational status (χ2 for linear trend=25.55, P< 0.001) was statistically significant. MLR analysis revealed a significant association between hypertension and various age categories and overweight/obesity. Interpretation & conclusions: The findings of the present study highlight high prevalence of hypertension among Nicobarese aborigenes.