Environmental predictors of diarrhoeal infection for rural and urban communities in south India in children and adults.

Diarrhoeal diseases are major causes of morbidity and mortality in developing countries. This longitudinal study aimed to identify controllable environmental drivers of intestinal infections amidst a highly contaminated drinking water supply in urban slums and villages of Vellore, Tamil Nadu in southern India. Three hundred households with children (<5 years) residing in two semi-urban slums and three villages were visited weekly for 12-18 months to monitor gastrointestinal morbidity. Households were surveyed at baseline to obtain information on environmental and behavioural factors relevant to diarrhoea. There were 258 diarrhoeal episodes during the follow-up period, resulting in an overall incidence rate of 0·12 episodes/person-year. Incidence and longitudinal prevalence rates of diarrhoea were twofold higher in the slums compared to rural communities (P < 0·0002). Regardless of study site, diarrhoeal incidence was highest in infants (<1 year) at 1·07 episodes/person-year, and decreased gradually with increasing age. Increasing diarrhoeal rates were associated with presence of children (<5 years), domesticated animals and low socioeconomic status. In rural communities, open-field defecation was associated with diarrhoea in young children. This study demonstrates the contribution of site-specific environmental and behavioural factors in influencing endemic rates of urban and rural diarrhoea in a region with highly contaminated drinking water.

Hantavirus infection among wild small mammals in Vellore, south India.

Wild indigenous small mammals including 83 rodents (bandicoot and black rats, and house mice) and a shrew captured from multiple sites in Vellore, south India, were tested for serological and molecular evidence of hantavirus infection. Indirect immunofluorescence assay (IFA) using Hantaan virus (HTNV) antigen indicated hantavirus-reactive antibodies in 16 (19.3%) of 83 rodents (bandicoot and black rats). Western blot (WB) using Thailand virus (THAIV) antigen confirmed hantavirus-reactive antibodies in nine of the 16 HTNV IFA-positive rodents. Reverse transcription polymerase chain reaction (RT-PCR) of lung and kidney tissue of captured mammals resulted in the detection of partial S segment sequence in a bandicoot rat. This study complements our earlier reports on hantavirus epidemiology in south India and documents first laboratory evidence for rodent-associated hantaviruses in south India.

Diabetes self-care activities: a community-based survey in urban southern India.

BACKGROUND: Diabetes is a lifestyle disease and can be successfully managed by good self-care activities such as diet, exercise, monitoring and drug adherence. Adequate baseline information about the prevalence of good self-care activities is not available from India. We aimed to estimate the existing self-care behaviours and factors influencing these behaviours among adult patients with type 2 diabetes in urban southern India. METHODS: A cross-sectional survey was conducted using a cluster design in an urban community in southern India. The Summary Diabetes Self-Care Activities questionnaire was used to collect information on diet, exercise, monitoring of blood sugars and adherence to drugs. Risk factors such as marital status, socioeconomic status, depression, benefit-finding and duration of illness, which are likely to influence self-care behaviour, were assessed. RESULTS: Good dietary behaviour was present in 29% (95% CI 20.8%-37.2%), good exercise behaviour in 19.5% (95% CI 17.4%-21.6%), regular blood sugar monitoring in 70% (95% CI 62.2%-77.8%) and drug adherence in 79.8% (95% CI 75.1%-84.5%). Being male (OR 3.38; 95% CI 1.541-7.407) and married (OR 5.60; 95% CI 1.242-25.212) significantly favoured good exercise behaviour. Being married (OR 2.322; 95% CI 1.104-4.883) and belonging to the higher socioeconomic status (OR 2.713; 95% CI 1.419-5.190) were significantly associated with monitoring of blood sugars. CONCLUSIONS: Self-care activities with respect to diet and exercise are poor in the population studied. The self-care activities relating to blood sugar monitoring and drug adherence are good. Improving self-care behaviour among patients with diabetes in India should start with adequate targeted health education.

Validity of a surveillance system for childhood injuries in a rural block of tamilnadu.

BACKGROUND: Childhood injuries are increasingly getting the attention of public health experts following WHO's report on global burden of diseases. Surveillance is an important component of control of any disease and effectiveness of the surveillance system depends upon completeness of the information about occurrence of the health related events to the public health authorities. AIMS: This study aimed to set up a surveillance system for childhood injuries and validate it by a survey and thereafter estimate the incidence of childhood injuries using capture recapture method. SETTINGS AND DESIGN: Observational study design. MATERIALS AND METHODS: Passive surveillance system for childhood injuries was created for 26,811 children of less than fourteen years of Kaniyambadi block and it was validated by cross sectional study at the end of surveillance period. Using these two independent information systems, capture recapture method was applied to find out the possible incidence of injuries in the given population at a given period of time. STATISTICS: Chi square, Lincoln Peterson formula for capture re-capture method. RESULTS: Surveillance and survey for childhood injuries identified 13.59/1000 child-years (CI: 11.86 - 15.32) and 341.89/1000 child-years (CI: 254.46-429.33) of injury rates, respectively. CONCLUSION: Passive surveillance system underreports childhood injuries markedly but it does identify childhood injuries of serious nature.

Hazardous alcohol use in rural southern India: nature, prevalence and risk factors.

BACKGROUND: There is a dearth of data on the hazardous use of alcohol in rural India. METHODS: We examined the nature, prevalence and factors associated with hazardous use of alcohol among men in a rural community in southern India. We used stratified sampling to select subjects from the Kaniyambadi block and employed 'AUDIT', a standard instrument, to assess the use of alcohol. RESULTS: The prevalence of life-time use, use in the past year and hazardous use of alcohol was 46.7%, 34.8% and 14.2%, respectively. Using Indian made foreign liquor (OR 20.51; 95% CI 8.81-47.75) and living in a village which brewed illicit alcohol (OR 2.82; 95% CI 1.39-5.72) were risk factors for hazardous use while education (OR 0.39; 95% CI 0.21-0.72) was protective. These factors remained significantly associated with hazardous use after adjusting for age and education using logistic regression. CONCLUSION: The relationship between the availability of illicit and commercial alcohol and its hazardous use suggests the need for an alcohol policy which takes into account health and economic issues and also implements the law to prevent the negative impact of problem drinking.

Incidence of Haemophilus influenzae type b meningitis in India.

BACKGROUND & OBJECTIVE: Vaccine policy depends on locally relevant disease burden estimates. The incidence of Haemophilus influenzae type b (Hib) disease is not well characterized in the South Asian region, home to 30 per cent of the world's children. There are limited data from prospective population incidence studies of Hib in Asia, and no data available from India. We therefore carried out this study to assess the burden of Hib meningitis in India. METHODS: A prospective surveillance study was carried out during 1997 and 1999 in hospitals for cases of Hib meningitis from 5 administrative areas of an Indian district (Vellore, Tamil Nadu) with 56,153 children under 5 yr of age, over a 24 month period RESULTS: Ninety seven cases of possible meningitis (> 10 WBC/microl in CSF) were reported, an annual incidence of 86 per 100,000 (95%CI 69 to 109) in 0-4 yr old children, and 357 per 100,000 in 0-11 month infants. Eighteen had proven bacterial meningitis, an annual incidence of 15.9 per 100,000. Eight CSF had Hib by culture or antigen testing, an annual incidence of 7.1 per 100,000 (95%CI 3.1 to 14.0) in children 0-59 months. In infants 0-11 months of age, the incidence of Hib meningitis was 32 per 100,000 (95%CI 16 to 67) and in the 0-23 month group it was 19 (95%CI 8 to 37). INTERPRETATION & CONCLUSION: Our data are the first minimal estimate of the incidence of Hib meningitis for Indian children. The observed incidence data are similar to European reports before Hib vaccine use, suggest substantial disease before 24 months of age, and provide data useful for policy regarding Hib immunization.

Solar disinfection of water for diarrhoeal prevention in southern India.

AIMS: To evaluate the efficacy and acceptability of solar irradiation in the prevention of diarrhoeal morbidity in children under 5 years of age, in an urban slum in Vellore, Tamil Nadu. METHODS: A total of 100 children were assigned to receive drinking water that had been subjected to solar disinfection in polyethylene terephthalate bottles. One hundred age and sex matched controls were also selected. Both groups were followed by weekly home visits for a period of six months for any diarrhoeal morbidity. At the end of the follow up period, the acceptability of the intervention was assessed by interviews, questionnaires, and focus group discussions. RESULTS: There was significant reduction in the incidence, duration, and severity of diarrhoea in children receiving solar disinfected water, despite 86% of the children drinking water other than that treated by the intervention. The incidence of diarrhoea in the intervention group was 1.7 per child-year, and among controls 2.7 per child-year, with an incidence rate ratio of 0.64 (95% CI -0.48 to 0.86). The risk of diarrhoea was reduced by 40% by using solar disinfection. In qualitative evaluation of acceptability, most women felt that solar disinfection was a feasible and sustainable method of disinfecting water. CONCLUSIONS: Solar disinfection of water is an inexpensive, effective, and acceptable method of increasing water safety in a resource limited environment, and can significantly decrease diarrhoeal morbidity in children.

Geographical information system (GIS) in investigation of an outbreak.

An outbreak of fever in a village in southern India was reported on 1st September, 2001. The first reported case presented with epistaxis and a platelet count of 27000h(1)/mm3. Clinical, laboratory and entomological evidence supported a diagnosis of dengue fever. One third of the village was affected and 3.7 % of the population presented with haemorrhagic symptoms; none were fatal. Five acute cases tested for dengue specific IgM showed that two were positive. The larvae of Aedes aegypti were discovered from domestic water collections in the village. Spatial analysis done with the help of Geographical Information Systems software (GIS) demonstrated a centrifugal spread of cases from the most affected street until it involved the entire village. Spatial analysis revealed that cases occurred in clusters and that these could not have occurred by chance. This was our first experience in producing a geo-referenced map of a village area and in spatial analysis. GIS is a novel and simple tool for outbreak investigations and the spatial analyst adds additional information to the data collected. Control of adult mosquitoes and larvae prevented the outbreak from spreading to an adjacent village.

Disease surveillance at district level: a model for developing countries.

For over a decade we have maintained within a district of 5 million people, a system of prompt reporting of cases of childhood vaccine-preventable diseases, encephalitis, meningitis, hepatitis, and rabies; together with a sentinel laboratory surveillance of cholera, typhoid fever, malaria, HIV infection and antimicrobial-resistance patterns of selected pathogens. The system combined government and private sectors, with every hospital enrolled and participating. Reports were scanned daily on a computer for any clustering of cases. Interventions included investigations, immunisation, antimicrobial treatment, health education, and physical rehabilitation of children with paralysis. All vaccine-preventable diseases have declined markedly, whilst malaria and HIV infections have increased steadily. Annual expense was less than one US cent per head. The reasons for the success and sustainability of this model include simplicity or reporting procedure, low budget, private-sector participation, personal rapport with people in the network, regular feedback of information through a monthly bulletin, and the visible interventions consequent upon reporting. This district-level disease surveillance model is replicable in developing countries for evaluating polio eradication efforts, monitoring immunisation programmes, detecting outbreaks of old or new diseases, and for evaluating control measures.

Laboratory surveillance of hepatitis C virus infection in England and Wales: 1992 to 1996.

Screening assay for antibody to hepatitis C virus (HCV) became available late in 1990 and their use has subsequently become widespread. Laboratories in England and Wales reported 5232 confirmed HCV infections to the PHLS Communicable Disease Surveillance Centre (CDSC) between 1992 and 1996. Fifty-seven per cent (2976) of reports included risk factor information, 80% of which (2382) identified injecting drug use as the main route of transmission. Thirty-one per cent of reports (1640) included clinical information: 41% (665) were asymptomatic, 57% (938) had symptoms, signs, or biochemical abnormalities of hepatic origin, and 2.2% (37) had non-hepatic conditions. To enhance these data two additional surveys have been undertaken to collect data on all anti-HCV tests performed in public health laboratories. In 1993, a retrospective survey of people tested between 1990 and 1993 revealed that the prevalence of antibody was highest (222/331 [67%]) among injecting drug users and recipients of blood or blood products (189/548 [34%]) and lower among other groups. In a prospective survey of HCV tests performed in transfusion recipients in early 1995, the prevalence of antibody was higher in those transfused before 1985 (11/418 [2.6%]) than in those transfused after 1985 (14/1441 [1.0%]). Reports of confirmed infections are a useful method of monitoring hepatitis C infection but additional data on testing are needed to interpret trends overall and in specific risk groups.

An epidemic of varicella in rural southern India.

In an epidemic of varicella investigated in rural southern India, an overall attack rate of 5.9% was observed. Attack rates were 15.9% among under-fives, 11.1% among school children (5-15 years) and 24% among those 16 years and more. None of the persons in the older age groups (16 years or more) suffered from severe forms of the illness or died. Among the 292 cases, three children (3,3 and 5 years of age) died (1% mortality). Their deaths were unusual since they occurred during convalescence from the illness, all three occurred at night during sleep, and all were girls. In the absence of a history suggestive of any known complication of varicella, hypoglycaemia following varicella as the cause of death is hypothesized. It is suggested that death following varicella among children may be more common in India than earlier believed while deaths or severe complications among adults may be rarer than in other countries.

An outbreak of anthrax meningoencephalitis.

We report a common-source outbreak of anthrax meningoencephalitis in Chittoor district in Andhra Pradesh, southern India, in October 1990. The source of infection was the carcass of a sheep. Of 5 persons who skinned and cut up its meat for human consumption, 4 developed anthrax meningoencephalitis and one a malignant pustule. Another person who wrapped the meat in a cloth and carried it home on his head developed a malignant pustule on his forehead and also meningoencephalitis. All subjects with anthrax meningoencephalitis died, but the one with only a malignant pustule recovered. A large number of people who cooked or ate the cooked meat of the dead sheep remained well. The medical, public health and veterinary authorities were alerted and sheep, goats and cattle in the locality were immunized with anthrax vaccine. Although rules against consumption of meat of dead animals exist, their violation shows a lack of public awareness. Health education should be undertaken to correct this situation.

Factors affecting immunization coverage levels in a district of India.

Immunization coverage is measured to assess the performance of the Expanded Programme on Immunization. In 1988 we conducted a coverage survey among 12-23 month-old children in the North Arcot District (population 5,007,746) in southern India. In each of the 12 towns a 30-cluster sample survey was conducted. In the 35 rural blocks with 1590 panchayats, 159 were selected systematically and all children (n = 7300) were surveyed. In the towns, coverage ranged for measles vaccine from 29 to 53%, BCG from 65 to 91% and OPV and DPT third dose from just over 60% to just over 80%. In the rural areas, coverage ranged for measles vaccine from 10.8 to 19.3%, BCG 25.1-34.1%, DPT third dose 42.2-50.4% and OPV third dose 39.6-48%. In the towns, 25, 66, 67 and 59% of BCG, DPT, OPV and measles vaccines had been provided by private agencies showing that availability of vaccines throughout the week and easy access even in payment terms played an important role in achieving higher levels of coverage compared with rural areas where all vaccines are given by Government agencies, free of charge. In the rural areas, significantly large variations in coverage were seen among panchayats--large and peri-urban panchayats had significantly better coverage than small and more rural panchayats. Within any given block (the population unit consisting of 30-40 panchayats served by a Primary Health Centre), there were large variations in the levels of immunization coverage between panchayats.(ABSTRACT TRUNCATED AT 250 WORDS)

PIP: The authors report findings from an immunization coverage survey in 1988 among 12-23 month old children in the North Arcot district of southern India conducted to assess the performance of the Expanded Program on Immunization. All 7300 children in 159 of 1590 systematically selected panchayats were surveyed. In the towns, coverages for measles vaccine ranged 29-52%, BCG 65-91%, and OPV and DPT 3rd dose 60-80%. Coverages in the rural areas were the following: measles vaccine, 10.8-19.3%; BCG, 25.1-34.1%; DPT 3rd dose, 42.2-50.4%; and OPV 3rd dose, 39.6-48%. In the towns, 25%, 66%, 67%, and 50% of BCG, DPT, OPV, and measles vaccines, respectively, were provided by private agencies. The higher coverage levels achieved in towns point to the importance of making vaccines available and easily accessible throughout the week. Government agencies provide all vaccines free of charge in rural areas. Further, large and peri-urban panchayats in rural areas had significantly better coverage than small and more rural ones, while large variations were found between panchayats in the levels of immunization coverage within any given block of 30-40 panchayats. The authors argue that variations in coverage levels in urban and rural areas and within rural areas may be due to varying efficiencies of different immunization delivery systems or responsible staff serving each region. In closing, neither the district nor block is a satisfactory unit for coverage surveys. Information should instead be collected from each geographical area served by a health worker to best detect poorly immunized areas. Coverage surveys should also ultimately be replaced with the auditing of immunization and disease surveillance.