Antimicrobial resistance in Shigella - rapid increase & widening of spectrum in Andaman Islands, India.

Background & objectives: Shigellosis is known to be a major cause of acute childhood diarrhoea in Andaman & Nicobar Islands, India. Rapid emergence of antibiotic resistance warrants continuous monitoring of sensitivity pattern of bacterial isolates. We report here the salient findings of an ongoing study on shigellosis in Andaman Islands, India, with regards to change in drug resistance pattern during the past one decade. Method: During 2006-2009, stools samples from 412 paediatric diarrhoea patients were collected and processed for isolation and identification of Shigella spp. Susceptibility to 22 antimicrobial drugs was tested and MICs were determined for 3rd generation cephalosporins, quinolones, amoxicillin-clavulanic acid combination and gentamicin. Drug susceptibility pattern of these isolates were compared with that of 33 isolates obtained during 2000-2002. Results: Shigella isolates were recovered from 50 of 412 stool samples processed. Resistance to ampicillin, nalidixic acid, tetracycline and ciprofloxacin was observed in 100, 96, 94 and 82 per cent of the isolates, respectively. The frequency of resistance to these drugs was significantly (P<0.001) higher than that observed during 2000-2002. Resistance to seven drugs was observed in 2000-2002, whereas resistance to 21 drugs was seen during 2006-2009. The number of drug resistance pattern increased from 13 in 2000-2002 to 43 in 2006-2009. Resistance to newer generation fluoroquinolones, 3rd generation cephalosporins and augmentin, which was not observed during 2000-2002, appeared during 2006-2009. Interpretation & conclusions: The frequency of resistance among Shigella isolates has increased substantially between 2000-2002 and 2006-2009 and the spectrum of resistance has widened. At present, the option for antimicrobial therapy in shigellosis in Andaman is limited to a small number of drugs. Continuous local monitoring of resistance patterns is necessary for the appropriate selection of empirical antimicrobial therapy.

Association of hypertension with risk factors & hypertension related behaviour among the aboriginal Nicobarese tribe living in Car Nicobar Island, India

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.

Tsunami, post-tsunami malaria situation in Nancowry group of islands, Nicobar district, Andaman and Nicobar Islands.

Background & objectives: Due to tsunami in 2004 a large proportion of population in Nicobar group of Islands become homeless, and in 2006 large scale labour migration took place to construct the houses. In 2008, a significant increase in malaria incidence was observed in this area. Therefore, in March 2008, the situation of malaria was assessed in Nancowry Islands in Nicobar District to study the reasons for the observed upsurge in the number of cases, and to suggest public health measures to control the infection. Methods: The methods included a retrospective analysis of long term trend in the behaviour of malaria over the years from 2001 to 2008, analysis of the acute malaria situation, and rapid fever and malaria parasitemia survey along with environmental component. Mass radical therapy (MRT) and post-intervention parasitemia survey were carried out. The malaria situation in the aftermath of MRT was analysed. Results: During the post tsunami year (2005) there was a large increase in the incidence of malaria and this trend continued till 2008. The percentage of Plasmodium falciparum increased from 23 to 53 per cent from 2006 to 2007 that coincides with the labour influx from mainland. The study showed that Nancowry was highly endemic, with high transmission setting, and high risk area for malaria. Though, more number of migrant labourers suffered fever (75 vs 20%) and sought malaria treatment over past month but parasitemia survey showed higher point prevalence of malaria among native tribes (7.4 vs 6.5%). Post-MRT, there was a decline in the occurrence of malaria, though it did not last long. Interpretation & conclusions: The study findings suggest that the migrant workers hailing from non-endemic or moderately endemic settings became victims of malaria in epidemic proportion in high endemic and high transmission setting. To find out the reasons for deterioration of malaria situation at Nancowry in the aftermath of tsunami requires further research.