Epidemiology & risk factors of scrub typhus in south India.

Background & objectives: Scrub typhus is a major public health threat in South and Southeastern Asian countries including India. Understanding local patterns of disease and factors that place individuals at risk is pivotal to future preventive measures against scrub typhus. The primary aim of this study was to identify specific epidemiological and geographical factors associated with an increased risk of developing scrub typhus in this region. Methods: We mapped 709 patients from Tamil Nadu, Andhra Pradesh and Telangana who were admitted to the Christian Medical College (CMC) Hospital, Vellore, Tamil Nadu, India, for the period 2006-2011, assessed seasonality using monthly counts of scrub typhus cases, and conducted a case-control study among a subset of patients residing in Vellore. Results: The geographic distribution of cases at CMC Hospital clusters around the Tamil Nadu-Andhra Pradesh border. However, distinct hotspots clearly exist distal to this area, near Madurai and the coast in Tamil Nadu, and in the Northeast of Andhra Pradesh. Seasonally, the highest numbers of cases were observed in the cooler months of the year, i.e. September to January. In the case-control analysis, cases were more likely to be agricultural laborers (OR 1.79, 95% CI 1.01 - 3.15), not wear a shirt at home (OR 4.23, 95% CI 1.12 - 16.3), live in houses adjacent to bushes or shrubs (OR 1.95, 95% CI 1.08 - 3.53), and live in a single room home (OR 1.75, 95% CI 1.02 - 3.01). On binary logistic regression, the first three of these variables were statistically significant. Interpretation & conclusions: With the growing number of cases detected in India, scrub typhus is fast emerging as a public health threat and further research to protect the population from this deadly infection is essential. Health education campaigns focusing on the agricultural workers of Southern India, especially during the cooler months of the year, can serve as an important public health measure to control infection.

Rotavirus-specific Salivary and Fecal IgA in Indian Children and Adults.

Objective: To compare serum, salivary and fecal IgA responses in infants and adults following rotavirus vaccination. Study design: Laboratory testing of samples from clinical trials. Setting: Medical College Hospital. Participants: 13 healthy adult volunteers not given vaccine, 20 healthy adult volunteers given one dose of bovine rotavirus tetravalent vaccine (Shantha Biotechnics), and 88 infants given 3 or 5 doses of Rotarix. Outcome measures: Serum, salivary and fecal IgA at one or more time points. Methods: IgA antibodies were estimated in serum, saliva and fecal samples by enzyme-linked immunosorbent assay, and normalized to total IgA in saliva. Results: In naturally infected adult volunteers, comparing serum and salivary IgA showed significant positive correlation (r=0.759; P=0.003). Of 20 vaccinated adults, complete samples showing change were available for 10; among them there was a significant positive correlation (P<0.05) between pre-vaccination serum and pre-vaccination salivary IgA but not between post-vaccination serum and post-vaccination salivary IgA. Of 88 infants given 3 or 5 doses of vaccine, 13 had more than 4-fold IgA response in serum, saliva and fecal samples, 6 had a 2-4 fold increases in all specimens. There was weak correlation between seroconversion rates measured by serum and salivary antibody responses. Salivary and stool assays were able to detect seroconversion in a few children in whom there was no detectable response in serum. Conclusions: Evaluation of multiple samples is useful for intensive experimental study designs and may help improve our understanding of the induction and dynamics of immune responses to rotavirus vaccination.

Racecadotril in the Management of Rotavirus and Non-rotavirus Diarrhea in Under-five Children: Two Randomized, Double-blind, Placebo-controlled Trials.

Objective: To study the effect of racecadotril on reduction in the duration of acute rotavirus and non-rotavirus diarrhea. Design: Two randomized double-blind placebo-controlled trials Setting: Community-based trial in an urban area in Vellore, hospital-based trial at a secondary hospital in Vellore Participants: 199 and 130 3-59 month old children in the community- and hospital-based trials, respectively. Methods: Racecadotril (1.5 mg/kg/dose, thrice a day for three days) or placebo were given to manage acute diarrhea in both trials. Main outcome measure: Median duration of diarrhea. Results: Among 124 children completing the hospital trial, the median duration of diarrhea was 25 h in both arms (P=0.5); median total stool weight was 74 g/kg and 53.5 g/kg in racecadotril group and placebo group, respectively (P=0.4); and average fluid intake per day was 3.6 mL/kg/h and 3mL/kg/h in racecadotril and placebo arms, respectively (P=0.3). Among rotavirus-positive children, median duration of diarrhea was 26.9 h and 30.2 h in racecadotril and placebo arms, respectively (P=0.7). In the community, 196 completed the trial, the median duration of diarrhea was 2 days for both arms (P=0.8) and rotavirus positive children had similar outcomes with median diarrheal duration of 3 d in both arms (P=0.4). Conclusion: Treatment with racecadotril did not reduce diarrheal duration, stool volume or the requirement for fluid replacement in children with acute gastroenteritis, both with and without rotavirus infection.

Study of Common Illnesses Before and After Vaccination: A Risk-interval Approach.

Objective: To compare the proportion of children who developed a specified illness in the 7 day post-vaccination window, with the background rate of the same event in the 7 day pre-vaccination window. Study design: Risk interval approach (Self-controlled caseseries). Setting: Well Baby Clinic of Christian Medical College, Vellore. Participants: 1602 healthy infants and under-six children presenting for routine vaccination. Outcome measures: Episode of any illness. Methods: The interviewer enquired about any adverse event or illness experienced by the child for each day of the week preceding the administration of age-appropriate vaccines. A second interview (telephonic) was conducted by the same interviewer one week following vaccine administration to enquire about adverse event(s) experienced by the child for each day of the subsequent week using a similar protocol. Results: With multiple vaccines delivered at appropriate ages, common childhood illnesses that could be reported as adverse events following immunization, except fever (RR=5.7, 95% CI=4.50-7.35), occurred at higher rates pre-vaccination. Risk Ratios of fever following whole cell (RR=9.3, 95% CI=6.43-13.52) and acellular (RR=8.5, 95% CI=3.82-18.91) vaccines were similar, with both showing a decreasing trend with increasing age. The gastrointestinal adverse event profile [diarrhea (RR=0.6, 95% CI=0.14-2.51) and vomiting (RR=1.0, 95% CI=0.14-7.10)] for rotavirus vaccine was similar pre- and post-immunization. Conclusions: Since most adverse events to vaccines are also common childhood illnesses, estimating the background rates of common illnesses is important to accurately ascertain a causal relationship.

Prevalence & risk factors for soil transmitted helminth infection among school children in south India.

Background & objectives: Soil-transmitted helminths (STH) are a major public health problem in tropical and sub-tropical countries, affecting the physical growth and cognitive development in school-age children. This study was aimed to assess the prevalence and risk factors of STH infection among school children aged 6 -14 yr in Vellore and Thiruvanamalai districts in south India. Methods: Children aged 6-14 yr, going to government and government aided schools (n=33, randomly selected) in Vellore and Thiruvanamalai districts were screened to estimate the prevalence of STH, and a case control study was done on a subset to assess the risk factors for the infection. Results: The prevalence of STH was 7.8 per cent, varying widely in schools from 0 to 20.4 per cent, in 3706 screened children. Hookworm (8.4%) rates were high in rural areas, while Ascaris (3.3%) and Trichuris (2.2%) were more prevalent among urban children. Consumption of deworming tablets (OR=0.25, P<0.01) offered protection, while residing in a field hut (OR=6.73, P=0.02) and unhygienic practices like open air defaecation (OR=5.37, P<0.01), keeping untrimmed nails (OR=2.53, P=0.01) or eating food fallen on the ground (OR=2.52, P=0.01) were important risk factors for STH infection. Interpretation & conclusions: Our study indicated that school children with specific risk factors in the studied area were vulnerable subpopulation with elevated risk of STH infection. Identifying risk factors and dynamics of transmission in vulnerable groups can help to plan for effective prevention strategies.

Direct costs of hospitalization for rotavirus gastroenteritis in different health facilities in India.

Background & objectives: Diarrhoeal disease is the fifth leading cause of all mortality globally. To this burden, rotavirus contributes over half a million deaths annually. This pilot study was conducted to determine the economic burden of diarrhoeal episodes on families from different geographical regions accessing medical facilities in India. Methods: Participants were enrolled from four study sites with eight reporting hospitals, categorized as non-profit and low cost, private and government facilities between November 2008 and February 2009. Questionnaires detailing healthcare utilization, medical and non-medical expenditure and lost income were completed by families of children < 5 yr of age hospitalized for gastroenteritis. All available faecal samples were tested for rotavirus. Results: A total of 211 patients were enrolled. The mean total cost of a hospitalized diarrhoeal episode was 3633 (US$ 66.05) for all facilities, with a marked difference in direct costs between governmental and non-governmental facilities. Costs for rotavirus positive hospitalizations were slightly lower, at 2956 (US$ 53.75). The median cost of a diarrhoeal episode based on annual household expenditure was 6.4 per cent for all-cause diarrhoea and 7.6 per cent for rotavirus diarrhoea. Of the 124 samples collected, 66 (53%) were positive for rotavirus. Interpretation & conclusions: Data on direct costs alone from multiple facilities show that diarrhoeal disease constitutes a large economic burden on Indian families. Affordable, effective vaccines would greatly reduce the economic burden of severe gastroenteritis on patients, families and the government.

Locally Made Ready-to-Use Therapeutic Food for Treatment of Malnutrition: A Randomized Controlled Trial.

Objective: To evaluate the effectiveness of a locally made ready-to-use therapeutic food (RUTF) in decreasing mild to moderate malnutrition. Design: A randomized open label, controlled trial. Setting: Pre-schools run by the Department of Community Health in Kaniyambadi administrative block, Vellore, India; duration of follow-up – 3 months from the date of recruitment. Participants: Pupils aged 18-60 months with Weight-for- Age ≤2 SD. Interventions: A locally produced energy-dense supplement (RUTF), and the current standard of care [teaching caregivers how to make a fortified cereal-milk supplement called High Calorie Cereal Milk (HCCM)]. Main outcome measures: Increase in weight-for-age status; increase in levels of plasma zinc, vitamin B12, serum albumin and haemoglobin. Results: The Mean (SD) weight gain at 3 months was higher in the RUTF group: RUTF (n=51): 0.54 kg; (SE = 0.05; 95% CI = 0.44 – 0.65) vs HCCM (n=45): 0.38 kg; (SE = 0.06; 95% CI = 0.25 – 0.51), P = 0.047. The weight gain per kilogram of body weight was directly proportional to the severity of malnutrition. Conclusions: Community-based treatment showed weight gain in both groups, the gain being higher with RUTF. Key words: India, Indigenous, Management, Malnutrition, Nutrition therapy.

Study of water supply & sanitation practices in India using geographic information systems: Some design & other considerations in a village setting.

Background & objectives: Availability of clean water and adequate sanitation facilities are of prime importance for limiting diarrhoeal diseases. We examined the water and sanitation facilities of a village in southern India using geographic information system (GIS) tools. Methods: Places of residence, water storage and distribution, sewage and places where people in the village defaecated were mapped and drinking water sources were tested for microbial contamination in Nelvoy village, Vellore district, Tamil Nadu. Results: Water in the village was found to be microbiologically unfit for consumption. Analysis using direct observations supplemented by GIS maps revealed poor planning, poor engineering design and lack of policing of the water distribution system causing possible contamination of drinking water from sewage at multiple sites. Interpretation & conclusions: Until appropriate engineering designs for water supply and sewage disposal to suit individual village needs are made available, point-of-use water disinfection methods could serve as an interim solution.

Investigation of a hepatitis A outbreak in children in an urban slum in Vellore, Tamil Nadu, using geographic information systems.

BACKGROUND & OBJECTIVE: An outbreak of symptomatic viral hepatitis in children less than 10 yr of age in Vellore, south India, was investigated and the disease pattern studied using serological and epidemiological methods, supplemented by geographic information systems (GIS) mapping. METHODS: Three cases of hepatitis A were identified during routine surveillance in a birth cohort House-to-house visits were undertaken to identify other symptomatic cases and samples collected for anti- HAV IgM, ELISA testing. All cases and controls were mapped and geo-referenced using Arc View GIS 3.3. Spatial clustering was investigated using SaTScan 7.0.1 software. Drinking water sources were tested for coliform counts with the most probable number technique. RESULTS: Of the 965 children surveyed, 26 (2.78%) had jaundice between February to July 2006. From the 26 patients, 11 (42.3%) blood samples were obtained and tested for anti-HAV IgM; 10 (90.9%) were found to be positive. Water analysis showed high coliform counts in all samples. No spatial clustering of cases could be detected. INTERPRETATION & CONCLUSION: The outbreak was identified because of the symptomatic presentation of the cases. Our study highlighted the increasing detection of symptomatic children with hepatitis A virus infection. Water sources in the area were contaminated and may have served as the source of infection. The lack of clustering in GIS analysis could be due to the common water source.