Rotavirus and other Diarrheal Disease in a Birth Cohort from Southern Indian Community.

Objective: To describe the incidence, severity and etiology of diarrheal disease in infants and young children residing in an urban slum community in Southern India. Setting: Three contiguous urban slums in Vellore, Tamil Nadu. Participants: 452 children participating in a birth cohort study on diarrheal disease; 373 completed three years of follow-up. Outcome measures: Diarrheal incidence (obtained by twice-weekly home visits) and severity (assessed by the Vesikari scoring system), and etiological agents associated with diarrhea (through examination of stool specimens by bacteriologic culture, rotavirus enzyme immunoassay, PCR for norovirus and microscopy for parasites). Results: A total of 1856 diarrheal episodes were reported in 373 children. The overall incidence rate of diarrhea was 1.66 episodes per child year for three years, with 2.76 episodes per child year in infancy. The incidence peaked during the months of July and August. Severe diarrhea formed 8% of the total episodes. Rotavirus was the most common pathogen detected, being identified in 18% of episodes. Good hygiene status resulted in 33% protection against moderate-to-severe diarrhea. Conclusions: This study highlights the burden of diarrheal disease and the important etiological agents of childhood diarrhea in Southern India. Promotion of hygienic behavior through health education may help reduce diarrheal incidence in this and similar communities.

Intestinal Permeability in Normally Nourished and Malnourished Children with and without Diarrhea.

We evaluated the association between diarrhea, malnutrition and intestinal function using the lactulose-mannitol test. Our study showed that a third of all children have abnormal intestinal permeability, there was an expected increase of permeability in children with acute diarrhea and alteration in intestinal permeability was greater in children with concurrent malnutrition and diarrhea

Detection and characterisation of rotaviruses from children less than 5 years hospitalised with acute gastroenteritis in Nagercoil.

Group A rotavirus continues to be the major cause of severe gastroenteritis in young children in developing countries. In this study, we report the prevalence and genotype of rotaviruses identified from children <5 years of age hospitalised with acute gastroenteritis from Nagercoil, Tamil Nadu from 2007-2010. From the 139 children included in the study, 71 samples (51%) were positive by ELISA and 65 samples were positive by PCR-based methods. G1P[8] (44.6%) was the most commonly identified genotype. In addition, we report detection of rotavirus in two of three CSF samples from children with seizures.

Epidemiology and Prospects for Prevention of Rotavirus Disease in India.

Context: With rotavirus vaccines now available globally, it will be useful to assemble the available evidence on the epidemiology and burden of rotavirus gastroenteritis in India, in order to weigh the urgency of introducing a vaccine to help control rotavirus disease. Evidence Acquisition: We reviewed published studies on rotavirus infection and genotype distribution in India, as well as safety and immunogenicity studies of currently available vaccines. PubMed was searched for papers published after 1990, and several authors who are experts in the field recommended papers of known significance. Results: Rotavirus accounts for close to 40% of hospitalizations for diarrhea in India, with more recent studies showing an increased proportion compared with older studies. There is substantial serotype diversity in India, although there is less intra-country variation than previously thought. Two genotypes, G1P[8] and G2P[4], account for roughly 50% of symptomatic infections in non-neonates. Currently licensed vaccines are safe, and although the efficacy appears lower in developing countries, given the extremely high incidence of diarrhea these could still be cost-effective interventions. Conclusions: The epidemiology and burden of rotavirus diarrhea is fairly well characterized in India. Introducing rotavirus vaccine into the UIP, along with adequate surveillance, should be an important part of efforts to reduce diarrhea mortality, the third leading cause of death among Indian children, and achieve the country’s MDG goals.

Detection and species identification of Campylobacter in stool samples of children and animals from Vellore, south India.

Campylobacter spp. are an important cause of bacterial gastroenteritis frequently isolated from animal, poultry and environmental samples. In this study, we investigated the zoonotic potential of Campylobacter spp. by comparing prevalence rates and species in 394 children with diarrhoea and 652 animals in Vellore using PCR-based tools. Eighteen children (4.5%) had campylobacteriosis, a majority of whom had co-pathogens (15/18) and most were infected with Campylobacter jejuni (16/18). A few C. coli and mixed infections with both species were also seen. Among the animal samples, 16/25 chicken samples (64%) were positive and all were found to be C. jejuni.

Comparison of primers for the detection of genogroup II noroviruses in India.

Purpose: Noroviruses (NoV) are increasingly recognized as an important cause for acute gastroenteritis, worldwide. Reverse transcription polymerase chain reaction (RT-PCR) and sequencing are the methods of choice for the detection of NoVs, but there is currently no consensus about the primers to be used in these assays. Materials and Methods: In this study, five published primer sets were evaluated for the detection of genogroup II (GII) NoVs in India. The primers target different regions of the NoV genome. Three primer sets detect an NoV in a single round RT-PCR platform, while the remaining two primer sets are based on a nested RT-PCR platform. Result: A panel of 100 samples from previous studies on norovirus diarrhoea in children were tested by all five primer sets. Of them, 74 samples were identified as positive for NoV, by at least one primer set. Subsets of positive amplicons were sequenced to check for specificity. Conclusion: The most sensitive primer set was Girish 2002, which detected GII NoV by nested RT-PCR, and was modified from the previously published primers. This study demonstrates that higher detection can be obtained by either using multiple primer sets or using a sensitive nested RT-PCR assay. It also demonstrates the differences in primer sensitivity for detection of Genogroup II (GII) NoVs in India.

Risk factors for acquiring Strongyloides stercoralis infection among patients attending a tertiary hospital in south India.

Purpose: Strongyloides stercoralis causes persistent and fatal disseminated infections in immunocompromised hosts. In this study, we aimed to determine the risk factors for acquiring strongyloidiasis and the associated morbidity in south India. Materials and Methods: The study was carried out in two parts. This included a 6-month chart review of cases with strongyloidiasis and randomly selected controls conducted to determine the association with immunocompromised states. Secondly, a cross-sectional study was conducted to investigate hyperinfection in human immunodeficiency virus (HIV)-infected adults where the stool and sputum samples were examined by microscopy for Strongyloides larvae. Results: In the chart review, 118 cases were compared with 240 controls. A higher proportion of patients on corticosteroids [8 (53.3%)] and with HIV infection [3 (60%)] had the risk of acquiring strongyloidiasis than not, although the difference was not statistically significant in this population. In the cross-sectional study, 14/239 HIV-positive individuals had Strongyloides larvae in the stool samples but none had Strongyloides detectable in their sputum samples. The CD4 cell counts were significantly lower in cases with Strongyloides compared with HIV-infected individuals with no parasites in their stool samples (P < 0.001). Conclusions: In this setting, strongyloidiasis was seen more often in patients on corticosteroid therapy and with HIV infection. In HIV, an association with lower CD4 counts indicates the need for inclusion of Strongyloides as an opportunistic parasite. Gram negative sepsis was an important complication of strongyloidiasis hyperinfection in both HIV and steroid therapy. Further prospective studies on the risk of developing complicated Strongyloides infection are required.

Needle stick injuries in a tertiary care hospital.

BACKGROUND: Accidental needle stick injuries (NSIs) are an occupational hazard for healthcare workers (HCWs). A recent increase in NSIs in a tertiary care hospital lead to a 1-year review of the pattern of injuries, with a view to determine risk factors for injury and potential interventions for prevention. METHODS: We reviewed 1-year (July 2006-June 2007) of ongoing surveillance of NSIs. RESULTS: The 296 HCWs reporting NSIs were 84 (28.4%) nurses, 27 (9.1%) nursing interns, 45 (21.6%) cleaning staff, 64 (21.6%) doctors, 47 (15.9%) medical interns and 24 (8.1%) technicians. Among the staff who had NSIs, 147 (49.7%) had a work experience of less than 1 year (n = 230, 77.7%). In 73 (24.6%) of the NSIs, the patient source was unknown. Recapping of needles caused 25 (8.5%) and other improper disposal of the sharps resulted in 55 (18.6%) of the NSIs. Immediate post-exposure prophylaxis for HCWs who reported injuries was provided. Subsequent 6-month follow-up for human immunodeficiency virus showed zero seroconversion. CONCLUSION: Improved education, prevention and reporting strategies and emphasis on appropriate disposal are needed to increase occupational safety for HCWs.

Infant mortality in an urban slum.

OBJECTIVE: Infant and child mortality are important indicators of the level of development of a society, but are usually collected by governmental agencies on a region wide scale, with little local stratification. In order to formulate appropriate local policies for intervention, it is important to know the patterns of morbidity and mortality in children in the local setting. METHODS: This retrospective study collected and analyzed data on infant mortality for the period 1995 to 2003 in an urban slum area in Vellore, southern India from government health records maintained at the urban health clinic. RESULTS: The infant mortality rate over this period was 37.9 per 1000 live births. Over half (54.3%) of the deaths occurred in the neonatal period. Neonatal deaths were mainly due to perinatal asphyxia (31.9%), pre-maturity (16.8%) and aspiration pneumonia or acute respiratory distress (16.8%), while infant deaths occurring after the first mth of life were mainly due to diarrheal disease (43%) and respiratory infections (21%). CONCLUSION: These results emphasize the need to improved antenatal and perinatal care to improve survival in the neonatal period. The strikingly high death rate due to diarrheal illness highlights the requirements for better sanitation and water quality.

Rotavirus vaccines.

Rotavirus, the most common cause of severe diarrhea and a leading cause of mortality in children, has been a priority target for vaccine development for the past several years. The first rotavirus vaccine licensed in the United States was withdrawn because of an association of the vaccine with intussusception. However, the need for a vaccine is greatest in the developing world, because the benefits of preventing deaths due to rotavirus disease are substantially greater than the risk of intussusception. Early vaccines were based on animal strains. More recently developed and licensed vaccines are either animal-human re-assortants or are based on human strains. In India, two candidate vaccines are in the development process, but have not yet reached efficacy trials. Many challenges regarding vaccine efficacy and safety remain. In addition to completing clinical evaluations of vaccines in development in settings with the highest disease burden and virus diversity, there is also a need to consider alternative vaccine development strategies.

Assessment, management and spatial distribution of ground water for irrigation in Rupnagar district of Punjab (India).

Ground water samples for geo-referenced sites were collected and analyzed for various chemical constituents for assessing their quality for irrigation. These waters were categorized as good and marginal sodic based upon the values of EC and RSC. The ground water quality map of the area was prepared and digitized using GIS software and blockwise area under different categories was commuted, which indicates that Kharar block (46.7 percent of the TGA) has maximum area under marginally sodic water as compared to the Anandpur Sahib block with 8.5 percent of its TGA under marginally sodic waters.

Intussusception in southern Indian children: lack of association with diarrheal disease and oral polio vaccine immunization.

BACKGROUND: Intussusception is the most common cause of intestinal obstruction in young children and has been reported as a complication of a recently withdrawn tetravalent reassortant rotavirus vaccine. METHODS: We studied the history, clinical presentation, management and outcome of intussusception presenting to a tertiary care hospital in southern India over a 10-year period, in order to assess potential association with diarrheal disease and immunization. RESULTS: Data from 137 index cases and 280 control subjects indicated that the risk of diarrheal disease or oral polio vaccine administration in the month prior to presentation was similar in the index cases and controls. Mean time to presentation to hospital after developing symptoms was 1.8 days, and 77.3% of patients required surgery, with 47.4% undergoing intestinal resection. Mortality was 0.006%. CONCLUSIONS: No association could be demonstrated between gastroenteritis or oral poliovirus vaccine immunization and intussusception in southern Indian children. These children presented later and required operative intervention more frequently than has been reported in other studies, but had a good outcome with low mortality.

A study on some phenotypic virulence markers of enteropathogenic Escherichia coli.

BACKGROUND & OBJECTIVES: The problem of enteropathogenic Escherichia coli (EPEC) causing diarrhoea in infants exists in India. But often the enteropathogenic status is not based on adequate characterization. Hence there is a need for evaluating the serotyping being used to identify EPEC for its validity in the light of recent knowledge on phenotypic markers of virulence. This study was done to evaluate the EPEC isolates for two potential virulence factors namely entero-adhesiveness with subsequent actin accumulation and verotoxin production. METHODS: Fifty consecutive EPEC strains identified by serotyping from stool samples of children with diarrhoea during January 1997 to June 1999 were studied for HEp-2 cell adherence, the fluorescent actin staining (FAS) characteristics of Hep-2 cells and vero cytotoxin production. RESULTS: Serotypes O55, O125 and O126 accounted for most of the isolates. In the Hep-2 assay, 72 per cent of the strains showed localised pattern of adherence and 22 per cent showed a mixed pattern of localised and diffuse adherence. In the FAS test 96 per cent strains showed typical staining while none of the strains produced verotoxin. INTERPRETATION & CONCLUSION: 'O' serogrouping appears to be still the simplest and an useful test for presumptive identification of EPEC. The FAS test for confirmation of EPEC was found to be very consistent in indicating EPEC.

Use of serology, the urease test & histology in diagnosis of Helicobacter pylori infection in symptomatic & asymptomatic Indians.

Age-specific prevalence of IgA and IgG antibodies in 714 subjects without gastrointestinal complaints aged 6 months to 90 yr was measured by an enzyme linked immunoassay using an acid-glycine extract of H. pylori as the antigen. The urease test and histology were used for the diagnosis of H. pylori infection in 83 subjects with a clinical diagnosis of dyspepsia, and these results were compared with measurement of IgG, IgA and IgM antibodies. The age specific prevalence of IgG and IgA antibodies respectively was 57 and 43 per cent for subjects aged 6 months to 4 yr and showed an increase with age to a maximum of 90 per cent for IgG in subjects > 60 yr of age and to 87 per cent for IgA in subjects between 51 and 60 yr. In symptomatic patients, there was a high degree of correlation between severity of H. pylori infection on histopathological examination and IgG (P < 0.02) levels. The use of IgG and IgA estimation could have identified H. pylori infection without endoscopy in 50 of the 83 patients. Serology for IgG and IgA antibodies against H. pylori may play a major role in decreasing the need for endoscopy, but cut-off values must be determined for each assay based on the prevalence of antibodies in the population.

Enteric pathogens in southern Indian HIV-infected patients with & without diarrhoea.

This study was undertaken to determine the carriage rate of various enteric pathogens in southern Indian patients with HIV infection, both with and without diarrhoea. Stool from 111 consecutive HIV-positive patients (50 without and 61 with diarrhoea) was examined by microscopy and culture. Jejunal biopsy and fluid examination were carried out if diarrhoea persisted, with negative stool examination. Enteric pathogens were detected from stool in 57.4 per cent of diarrhoeal patients compared to 40 per cent of those without diarrhoea (P > 0.05). Jejunal biopsy and fluid examination provided 11 additional diagnoses. Protozoa accounted for 71.8 per cent of all pathogens isolated. Isospora was significantly more common in patients with (11/61) than in those without (2/50) diarrhoea (P < 0.05). Bacterial pathogens were isolated more commonly from patients with diarrhoea (12/61 compared to 2/50, P < 0.05). Isolation rate of pathogens was higher from patients with diarrhoea for more than 2 wk, compared to those with less than 2 wk duration. Remission of diarrhoea either spontaneously or with symptomatic therapy was observed in 22 patients with acute diarrhoea. A high enteric carriage of a number of pathogens was noted in HIV patients without diarrhoea, but I. belli and bacterial enteropathogens were more likely to be associated with diarrhoea.

Oxidative stress response in Shigella & nonpathogenic gut bacteria.

The effect of oxidative stress in the form of exogenous H2O2 on the survival of four species of Shigella and two nonpathogenic Gram negative gut bacteria and the role of catalase as an antioxidant enzyme, neutralizing the effect of H2O2 were examined. A significant decrease in the number of colony forming units (CFUs) after exposure to exogenous H2O2 (122 +/- 37), compared to control bacteria (218 +/- 63, P < 0.001) was observed. There was an induction of catalase activity after exposure to exogenous H2O2 and the specific activity of catalase in H2O2 exposed bacteria was significantly increased (2.88 +/- 1.25), compared to control bacteria (1.5 +/- 0.44; P < 0.05). A direct correlation was observed between the decrease in bacterial counts and increase in catalase activity after exposure of H2O2 (regression coefficient (0.56). Gut bacteria appear to be susceptible to oxidative stress and inducible catalase activity may form an important part of the antioxidant defence mechanism against oxidative stress.