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Acute diarrhoea remains a major public health challenge in developing countries. We examined the role of a probiotic in the prevention of acute diarrhoea to discover if there was an effect directed towards a specific aetiology. A double-blind, randomized, controlled field trial involving 3758 children aged 1-5 years was conducted in an urban slum community in Kolkata, India. Participants were given either a probiotic drink containing Lactobacillus casei strain Shirota or a nutrient drink daily for 12 weeks. They were followed up for another 12 weeks. The primary outcome of this study was the occurrence of first episodes of diarrhoea. We assessed this during 12 weeks of intake of study agent and also for 12 weeks of follow-up. There were 608 subjects with diarrhoea in the probiotic group and 674 subjects in the nutrient group during the study period of 24 weeks. The level of protective efficacy for the probiotic was 14% (95% confidence interval 4-23, P<0·01 in adjusted model). The reduced occurrence of acute diarrhoea in the probiotic group compared to nutrient group was not associated with any specific aetiology. No adverse event was observed in children of either probiotic or nutrient groups. The study suggests that daily intake of a probiotic drink can play a role in prevention of acute diarrhoea in young children in a community setting of a developing country.

In this study, we have analysed the epidemiological significance of the concurrent infections caused by Vibrio cholerae and intestinal parasites among different age groups of hospitalized diarrhoeal patients in Kolkata. A total of 3556 stool samples collected during 1996-2004 were screened for vibrios and parasites. The seasonality of V. cholerae and parasitic infections were studied in detail. The detection rates for Ascaris lumbricoides and Giardia lamblia infection were more than for the hookworm, Trichuris trichiura and Entamoeba histolytica. V. cholerae O1 was identified as the predominant serogroup among diarrhoeal patients. The highest rates for V. cholerae infection were in the 2-5 years age group and combined infection of V. cholerae and parasites was recorded among children aged between 2 and 10 years.

Picobirnaviruses (PBVs) with bisegmented small RNA genome profile (1.75 and 1.55kbp for segment 1 and 2, respectively) were detected from 1999 to 2003 in faecal specimens of acute watery diarrhoea cases, largely children (n=20) and an adult in Kolkata, India. Varying degrees of dehydration necessitated their visit to hospital for further treatment and management of acute watery diarrhoea. PBV was associated with rotavirus (n=3) or astrovirus (n=3) and with both in one case. No co-infection with norovirus, sapovirus or adenovirus was detected in the picobirnavirus positive cases. No co-infection with parasites (Cryptosporidium spp., Giardia spp., Entamoeba spp., helminths) or bacteria (Vibrio spp., Shigella spp., Escherichia coli) was detected among the picobirnavirus positive cases. There was a single instance of co-infection with Salmonella spp. (n=1). PBVs not associated with serious diarrhoea illness and showing large genome profile (2.3-2.6 and 1.5-1.9kbp for segment 1 and 2, respectively) have earlier been reported in adult individuals and recently among children from a slum community in Kolkata, India. The short genome profile PBVs associated with acute watery diarrhoea may be another emerging diarrhoeagenic virus in Kolkata, India. Molecular characterization using reported primers PicoB25-PicoB43 for Genogroup I and PicoB23-PicoB24 for Genogroup II in RT-PCR showed the presence of Genogroup I PBVs (n=6) and Genogroup II PBVs (n=5), while some could not be amplified (n=3) with these primers. Sequence analysis of Genogroup I amplicons indicated remarkable sequence heterogeneity. After more than a decade, four PBV positives of Genogroup II were detected during this study. Phylogenetic analysis showed varying degree of genetic diversity amongst PBV strains from Kolkata and other countries.

Background: Human group B rotavirus was first identified as causative agent of a large outbreak of severe gastroenteritis affecting more than 1 million people, predominantly adults in China in 1982-1983. In spite of serological evidences for the presence of group B rotavirus in many countries of the world, the virus has been detected only from China, India and Bangladesh, where most of the cases were from adults., Objectives: To ascertain the role of group B rotavirus as an aetiological agent of diarrhoea among children in Kolkata, India., Study Design: An active surveillance was conducted for rotavirus infection in children in a leading referral paediatric hospital and a few samples were also collected from adults of another hospital in Kolkata, India over a period of 3 years (2002-2004). After primary screening of rotaviruses by RNA electrophoresis in polyacrylamide gel, 200 of 412 samples negative by PAGE were screened by reverse transcription polymerase chain reaction for group B rotaviruses. The group B rotavirus positives samples were also confirmed by dot-blot hybridization., Result: During the study period, we detected 37 (18.5%) sporadic cases of human group B rotavirus infection in children below 3 years of age of which 15 (7.5%) showed mixed infection with group A rotaviruses by RT-PCR. In dot-blot hybridization studies the RNA of all rotavirus positive samples hybridized with the nonisotopic psoralen-biotin labeled total RNA probe generated from a human group B rotavirus CAL-1 strain confirming the samples as group B rotaviruses., Conclusion: The shift in age preference of group B rotavirus infection from adult to children and mixed infection of group B and group A rotaviruses reveals the importance of group B rotavirus as an etiological agent of childhood diarrhoea. Therefore, future vaccination strategy should include both group A and B rotaviruses to control rotavirus diarrhoea.

Background: Rotavirus genotypes, G1-G4 and G9 are associated with childhood diarrhoea throughout the world. In our previous study, we detected G1, G2, G4 and three G12 strains from Kolkata, India., Objectives: To study the prevalence of G- and P-genotypes of rotaviruses associated with dehydrating diarrhoea in children admitted to two leading hospitals in eastern India., Study Design: An active surveillance was conducted for elucidation of rotavirus infection in two leading hospitals in Kolkata, West Bengal and Berhampur (GM), Orissa, India, separated by 603km from January 2003 to April 2005. The rotaviruses were detected by RNA electrophoresis in polyacrylamide gels. G- and P-typing of the positive samples were accomplished by amplifying VP7 and VP4 genes by RT-PCR and genotyped by seminested multiplex PCR methods. Sequencing, sequence analysis and phylogenetic analysis of VP7 genes of G12 strains were carried out to understand the variations between the strains isolated from different parts of the world., Results: The genotypic distribution varied remarkably from our earlier study period (1998-2001) with G1 (53.8%) being the most predominant strain followed by G2 (22.5%), G12 (17.1%), G9 (2.1%) and not a single G3 or G4 isolate was detected separately. 35.2% samples exhibited mixed P-types followed by P[4] (31.7%), P[8] (21.8%) and P[6] (9.8%). The phylogenetic analysis of G12 strains revealed that the G12 strains detected from different parts of the world clustered into three different lineages. Though VP7 sequences of G12 strains isolated from Kolkata and Berhampur are conserved, their P-types were different., Conclusion: During this study period we reported emergence of G12 strains as an important pathogen among children in eastern India, thus necessitating its inclusion in future polyvalent vaccine to control rotavirus diarrhoea.

Acute diarrhoeal diseases rank second amongst all infectious diseases as a killer in children below 5 years of age worldwide. Globally, 1.3 billion episodes occur annually, with an average of 2-3 episodes per child per year. The important aetiologic agents of diarrhoea and the guidelines for management are discussed. Management of acute diarrhoea is entirely based on clinical presentation of the cases. It includes assessment of the degree of dehydration clinically, rehydration therapy, feeding during diarrhoea, use of antibiotic(s) in selected cases, micronutrient supplementation and use of probiotics. Assessment of the degree of dehydration should be done following the WHO guidelines. Dehydration can be managed with oral rehydration salt (ORS) solution or intravenous fluids. Recently WHO has recommended a hypo-osmolar ORS solution for the treatment of all cases of acute diarrhoea including cholera. Feeding during and after diarrhoea (for at least 2-3 weeks) prevents malnutrition and growth retardation. Antibiotic therapy is not recommended for the treatmentof diarrhoea routinely. Only cases of severe cholera and bloody diarrhoea (presumably shigellosis) should be treated with a suitable antibiotic. Pilot studies in several countries have shown that zinc supplementation during diarrhoea reduces the severity and duration of the disease as well as antidiarrhoeal and antimicrobial use rate. Probiotics may offer a safe intervention in acute infectious diarrhoea to reduce the duration and severity of the illness.

This study was undertaken to measure the impact of periodic deworming with albendazole on growth status and incidence of diarrhoea in children aged 2-5 years in an urban setting in India and to assess the feasibility of local health workers implementing the procedures involved. This was a double-blind, placebo-controlled, randomized, community-based intervention trial with 702 children randomly allocated to receive either albendazole or placebo. The two study groups received two doses of albendazole (400 mg) or placebo six months apart. Mean weight increased significantly in the albendazole group compared to the control group at three months, six months and nine months following treatment (P<0.01, P<0.01 and P<0.001 respectively). The albendazole group also experienced fewer episodes of diarrhoea than their control counterparts (relative risk 1.3, 95% CI 1.07-1.53) with a 28% reduction. The health workers administered the correct dosage satisfactorily and there were no adverse effects. Thus, periodic mass deworming with albendazole would seem to be a safe and effective method that could be adopted at the community level or as an integral part of school health services and could be expected to improve growth and reduce the incidence of diarrhoea in children.

An outbreak of acute diarrhoeal disease occurred in Dhalai and North Tripura district, Tripura during month of May 2004. An investigation was done to identify causative agent with anti microbial susceptibility pattern and to know the epidemiological feature. Overall attack rate and Case Fatality Rate (CFR) was 18.8%. and 6.9/1000 respectively. Vibrio cholerae O1 biotype El Tor, Ogawa was isolated as sole pathogen in 40% of hospitalized acute diarrhoea patient and from a water samples examined. The strains were sensitive to Tetracycline, Doxycycline, Norfloxacin, Ciprofloxacin, Chloramphenicol, and Azithromycin. Bad peridomestic sanitation, use of contaminated surface water along with low literacy, lack of personal hygiene, frequent movement might be the factor associated with persistence and spread of pathogen amongst tribal groups leading to outbreak of cholera.

Enteroaggregative Escherichia coli (EAEC) is an important diarrheal enteropathogen defined by aggregative adherence to cultured epithelial cells. We have detected EAEC from 121 (6.6%) of 1,826 hospitalized patients admitted with diarrhea to the Infectious Diseases Hospital in Kolkata, India. Watery diarrhea was recorded significantly (P = 0.0142) more often in children. The majority of the EAEC isolates were not serotypeable (62%) and showed resistance to five or more antibiotics (76%). We studied different virulence genes and the molecular epidemiology of 121 EAEC isolates recovered from diarrheal patients. A PCR assay for detection of virulence genes, an assay for determination of clump formation in liquid culture, and a HeLa cell adherence assay were carried out to characterize the EAEC isolates. Investigations were also conducted to correlate the virulence gene profiles with diarrheal symptoms and molecular epidemiology by pulsed-field gel electrophoresis (PFGE). Two or more virulence genes were detected in 109 (90.1%) EAEC isolates. In the cluster analysis, some isolates with specific gene profiles and phenotypes formed a group or subcluster. This study highlights the comparative distributions of three fimbrial adhesins and other virulence genes among EAEC isolates. The diverse virulence gene and PFGE profiles, along with the existence of diverse serotypes and antibiograms, suggests that the EAEC isolates are genetically heterogeneous in Kolkata.

A comprehensive study was performed to examine incidence, species distribution, drugs sensitivity, virulence genes and molecular fingerprints of Aeromonas species isolated from patients with acute diarrhoea over a period of 2 years in Kolkata, India. Following the Aerokey II scheme, more than 95 % of strains were identified to species level. Seven different species were encountered in this study, with Aeromonas caviae being dominant, followed by Aeromonas hydrophila and Aeromonas veronii biovar sobria. Thirty different serotypes were encountered, with O16, O83 and O85 being dominant, but no serotype was associated specifically with a single species. The majority of Aeromonas strains exhibited multidrug resistance. The alt and act genes, which encode heat-labile cytotonic and cytotoxic enterotoxins, were respectively found in 71.9 and 20.1 % of strains examined. Only 2.4 % of strains carried the heat-stable cytotonic enterotoxin (ast) gene. The hlyA gene was found in 28 % of Aeromonas strains. With few exceptions, genomic diversity of Aeromonas strains belonging to the same serotype was observed by random amplification of polymorphic DNA PCR and ribotyping. Different species of Aeromonas and different clones of Aeromonas species seem to be associated with hospitalized cases of diarrhoea in Kolkata, India.

Diarrhoeal infection caused by Escherichia coli is common in India with occasional outbreaks. However, association of different pathotypes of diarrhoeagenic E. coli (DEC) with the disease and its phenotypic and genotypic characteristics are not fully demonstrated. In this study, E. coli strains from sporadic cases and outbreaks of diarrhoea during 2000-2001 were confirmed as DEC by polymerase chain reaction (PCR) targeting the specific virulence genes. DEC represented by enterotoxigenic E. coli (ETEC), enteropathogenic E. coli (EPEC) and enteroaggregative E. coli (EAggEC) were mostly belonged to O serogroups 25, 86a, 114 and 146. The gene astA was frequently detected among ETEC and EAggEC than EPEC. After initial screening of 200 DEC strains with serology and antibiotic susceptibility test, 32 strains representing ETEC, EPEC, and EAggEC isolated from different areas of India were included in the pulsed-field gel electrophoresis (PFGE) analysis. Using the PFGE results, the hierarchical representation of different linkage levels between the DEC strains were determined by unweighed pair-group arithmetic mean (UPGAMA) method. Except for few strains, clonotyping by PFGE revealed no correlation between pathotypes and serogroups as well as the place of isolation of the DEC strains. The prevailing clonal diversity among the different categories of DEC strains suggests that the pathotypes of DEC belonged to diverse clones.

Three rare human G12 strains were detected from diarrheic clinical samples of children (<8 months of age) in Calcutta during a routine surveillance study of rotaviral diarrhea in India. The VP7 genes of G12 strains and their products showed maximum homology (97 to 99% at the nucleotide level and 98% at the amino acid level, respectively) with those of two recently reported G12 strains (from the United States and Thailand) but lesser homology with those of prototype G12 strain L26.

Acute diarrhoeal diseases constitute one of the major health problems among young children in India. It was estimated in 1978 that 1.5 million children under the age of 5 years die due to diarrhoea every year, which declined to 0.6-0.7 million in the estimate revised in 1992. A similar declining trend has also been noted in hospitalized cases in Calcutta (present Kolkata) during 1980-95 as well as from other parts of India. Even today, cholera epidemics occur regularly in India. The cholera epidemic caused by a novel strain of Vibrio cholerae, designated as V. cholerae 0139 Bengal in 1992 and multidrug-resistant shigellosis in eastern India in 1984 are matters of grave concern. The launching of the National Diarrhoeal Diseases Control Programme (CDD) in 1978, based on a three-tier approach, is of great importance. The rate of use of oral rehydration salt (ORS) solution and oral rehydration therapy (ORT) remain suboptimal in India. In spite of the launching of the 'Ganga Action Plan' and the 'National River Action Plan', India faces a major problem of diarrhoeal diseases. Lack of safe water supply, poor environmental sanitation, improper disposal of human excreta and poor personal hygiene help to perpetuate and spread diarrhoeal diseases in India. Since diarrhoeal diseases are caused by 20-25 pathogens, vaccination, though an attractive disease prevention strategy, is not feasible. However, as the majority of childhood diarrhoeas are caused by V. cholerae, Shigellae dysenteriae type 1, rotavirus and enterotoxigenic Escherichia coli (E. coli) which have a high morbidity and mortality, vaccines against these organisms are essential for the control of epidemics. A strong political will with appropriate budgetary allocation is essential for the control of childhood diarrhoeal diseases in India, a formidable task in a country with a population of over 1 billion.

A combined reverse transcriptase-polymerase chain reaction (RT/PCR) was used to produce cDNA of the VP7 gene of rotavirus present in the stool samples. A total of 150 rotavirus positive stool samples were used in this study. Multiplex PCR, using the type specific primers, revealed the presence of G1 (49/150, 32.7%), G2 (27/150, 18%) and G4 (30/150, 20%) genotypes among the samples collected during 1999-2000 from children suffering from acute watery diarrhea. Eighteen samples (12%) were of mixed genotype and the remaining 16 samples (10.6%) could not be typed. Comparative analysis of the full length genes of the representative strains with corresponding genotypes incorporated in the human-rhesus rotavirus tetravalent vaccine (RRV-TV) formulation demonstrates variations of the circulating G1, G2 and G4 strains with the corresponding G genotypes present in the vaccine strain.

The prevalence of Salmonella enterica serotypes, antimicrobial susceptibility, and phage typing of serovers were studied. Clinical presentations of the infected cases were also examined. The study was carried out during August 1993-September 1996 in and around Calcutta, India. In total, 1,025 faecal samples from hospitalized diarrhoeal children were screened for enteropathogens. Four S. enterica serotypes were identified in 157 (15.3%) cases as a single pathogen. S. enterica serotype Typhimurium was detected in 110 (70%) cases. S. Seftenberg, S. Infantis, and S. Virchow were detected in 28 (17.8%), 14 (8.9%), and 5 (3.2%) cases respectively. S. Typhimurium was isolated from 11 (3.2%) non-diarrhoeal control children. All of these children had acute watery diarrhoea, and 5% of them had severe dehydration, 40% had some dehydration, and 55% had no dehydration. Vomiting, fever, and diffused pain in abdomen were the associated presentations of these children. Most (95%) of them recovered with oral rehydration therapy only and without any antibiotics. In-vitro susceptibility testing showed that 120 of the 121 S. Typhimurium strains isolated from cases and controls were resistant to the commonly-used drugs. Thirteen of the 121 strains were phage-typeable and belonged to the phage type 193. However, no clinical or epidemiological significance could be established with these typeable strains. The findings of the study indicate that diarrhoeagenic Salmonella is one of the major pathogens causing diarrhoeal diseases in eastern India.

As the sensitivity of the conventional techniques for identifying Shigella spp. and enteroinvasive Escherichia coli (EIEC) causing dysentery cases is low, a PCR assay was evaluated in this study. Analytical sensitivity (2 x 10(2) cfu) of the PCR technique was obtained by artificially spiking negative stool samples with a standard strain of S. flexneri type 2, then determining the detection limit. Specificity (100%) of the method was determined by testing a number of known Shigella and EIEC strains and organisms other than Shigella spp. A total of 300 stool samples collected from children with acute diarrhoea was plated on to two selective agar media after enrichment in Luria broth. Shigella spp. were isolated from 7.7% (23 of 300) and EIEC from 1% (3 of 300) patients. All enriched stool samples were subjected to PCR to amplify the target sequence of invasive plasmid antigen (ipa)H locus, a multicopy element found on the chromosome and invasion plasmid. The stool PCR was positive in 24 of the 26 culture-positive and in 22 culture-negative stools, thus detecting the presence of Shigella spp. or EIEC in 15.3% (46 of 300) of diarrhoea cases. When an ial probe was used for colony hybridistion with enriched stool cultures blotted on to membranes, 9.6% (29 of 300) of dysentery cases were identified as being caused by Shigella spp. or EIEC. Thus the sensitivity of enriched stool culture, colony hybridisation and enriched stool PCR was found to be 54%, 60% and 96%, respectively, when each of the methods was compared to the total microbiologically confirmed cases of dysentery. It was also observed that only 38% (48 of 126) of acute bloody dysentery cases actually had shigella or EIEC infection, as confirmed by laboratory methods. Moreover, this PCR assay could identify a number of untypable Shigella strains (Sh OUT), which would have remained undiagnosed had this assay not been used.

Aims: To compare the clinical efficacy of hypo-osmolar oral rehydration salt (ORS) solution (224 mmol/l) and standard ORS solution (311 mmol/l) in severely malnourished (marasmic) children having less than 60% Harvard standard weight for age with dehydrating acute watery diarrhoea., Methods: In a double blind, randomised, controlled trial, 64 children aged 6-48 months were randomly assigned standard (n = 32) or hypo-osmolar ORS (n = 32)., Results: Stool output (52.3 v 96.6 g/kg/day), duration of diarrhoea (41.5 v 66.4 hours), intake of ORS (111.5 v 168.9 ml/kg/day), and fluid intake (214.6 v 278.3 ml/kg/day) were significantly less in the hypo-osmolar group than in the standard ORS group. Percentage of weight gain on recovery in the hypo-osmolar group was also significantly less (4.3 v 5.4% of admission weight) than in the standard ORS group. A total of 29 (91%) children in the standard ORS group and 32 (100%) children in the hypo-osmolar group recovered within five days of initiation of therapy. Mean serum sodium and potassium concentrations on recovery were within the normal range in both groups., Conclusion: Our findings suggest that hypo-osmolar ORS has beneficial effects on the clinical course of dehydrating acute watery diarrhoea in severely malnourished (marasmic) children. Furthermore, children did not become hyponatraemic after receiving hypo-osmolar ORS.

Background and Objectives: a number of studies have shown the association between vitamin A deficiency and the increased risk of diarrhoeal and other childhood morbidities and mortality. However, some studies have raised controversies regarding the reduction of the incidence of diarrhoea after vitamin A supplementation to children. This study was undertaken to evaluate the effectiveness of vitamin A supplementation to young rural children in reducing the incidence of diarrhoea., Methods: a double-blind randomized intervention trial was carried out amongst 404 rural children between 6-59 months of age to assess the impact of vitamin A supplementation on morbidity due to diarrhoea. Children aged 6-59 months were enrolled and allocated to receive either 200,000 or 50,000 IU of vitamin A and the same dose was repeated after six months. Morbidity due to diarrhoea was observed by twice-a-week household surveillance, during the subsequent one year of follow up. The incidence of diarrhoea was compared between the two supplemented groups. In addition, the overall incidence of diarrhoea n the two supplemented groups was also compared with the incidence observed during the year preceding supplementation., Results: the incidence of diarrhoea was similar in the two supplemented groups (Incidence Rate Ratio = 1.05. 95% C. I. 0.79-1.40). However, the overall incidence of diarrhoea among all the children in the two supplemented groups (0.56 episodes/child/year) was significantly lower than the incidence before supplementation (1.15 episodes/child/year). The Incidence Rate Ratio was 0.49 with 95% C.I 0.40-0.59., Interpretation and Conclusions: the results of this study indicate that vitamin A supplementation in a dose of 200,000 IU, has no additional advantage over 50,000 IU, at least when the aim is to reduce the incidence of diarrhoea. For control of morbidity due to diarrhoea, vitamin A supplementation in a dose of 50,000 IU every six months appears to be adequate, cost effective and suitable for younger children.

Background & Objectives: Klebsiella pneumoniae strains occasionally cause diarrhoea in humans. This study was done to determine the involvement of calcium in the pathogenesis of aggregative K. pneumoniae strains., Methods: A total of nine strains of K. pneumoniae were tested for adherence assay in HeLa cell line. A representative strain CO-1215 was used for [Ca2+]i study using Fura-2 fluorescence., Results: Infection of cultured HeLa cells with aggregative K. pneumoniae strain resulted in five-fold elevation of intracellular level of free calcium ([Ca2+]i) with maximum Ca2+ influx at 3 h after bacterial infection. Chelation of extracellular Ca2+ with [ethylenebis(oxyethylenenitrile)] tetraacetic acid and suspension of cells in Ca2+ free buffer suggested that the rise of Ca2+ in aggregative K. pneumoniae infected HeLa cells was due to influx of Ca2+ from extracellular medium., Interpretation & Conclusions: This study showed aggregative adherence in HeLa cells and this adherence leads to influx of extracellular Ca2+. The unrestricted passage of calcium ions across cell membranes could cause phosphorylation of proteins involved in ion transport across the membrane, which could result in secretory diarrhoea. Further work is in progress to study the enterotoxicity of these strains in an in vitro rabbit intestinal model.

During the months of May, June and through early part of July 1994, an unusual occurrence of severe dehydrating watery diarrhoea cases and deaths were reported from Aizwal town, the capital of Mizoram, a North-Eastern state of India. Vibrio cholerae 01 biotype Eltor, the causative agent responsible for this outbreak, was isolated from 50.0% of hospitalised cases. The disease affected older children and adults more (52.9%) than younger children below five years of age. Vibrio cholerae 01 strains isolated were uniformly resistant to furazolidone and co-trimoxazole, which are commonly advocated in the treatment of cholera specially in children of developing countries. Emergence of such resistant strain is alarming and is of great public health importance.

The prevalence of different serotypes of non-typhoidal Salmonella spp. among patients suffering from acute diarrhoea admitted to the Infectious Diseases Hospital, Calcutta was investigated. The predominant serogroup was C and Salmonella infantis was the major serotype isolated followed by S. worthington, S. enteritidis, S. typhimurium, S. weltevereden and S. newport. All the Salmonella strains were isolated from adults. Multidrug resistance to various antimicrobial agents was observed in 37.5 per cent of the strains. All the strains were sensitive to ciprofloxacin, norfloxacin and gentamycin.

Knowledge of rural mothers related to five diarrhoeagenic risk behaviours, identified in an earlier study, was ascertained. A high proportion of mothers (67%-79%) had knowledge about risk of bottle feeding, non-use of soap for cleaning feeding containers, storage of drinking water in wide-mouthed vessels and indiscriminate disposal of children's faeces. However, only around 31% of mothers were aware about danger of using pond water for cleaning feeding containers. Risk behavioural practices were less amongst mothers who had knowledge about them. Risk of diarrhoea amongst children of mothers having risk practice without knowledge as compared to those who utilised their knowledge to avoid risk practice was found significantly higher (p < or = 0.005) except for bottle feeding (p = 0.330). The results of this study indicate that children can be protected significantly from diarrhoea if mothers' diarrhoeagenic behaviours can be altered through educational intervention.

Acute diarrhoeal diseases are an important cause of morbidity and mortality, particularly in children. Acute diarrhoea may be watery, where features of dehydration are more prominent or dysenteric, where the stools contain blood and mucous. Rehydration therapy is the key to the management of acute watery diarrhoea, whereas antibiotics play a vital role in the management of acute invasive diarrhoea, particularly shigellosis. Rehydration may be done either by the oral or intravenous routes depending upon the degree of dehydration. Oral rehydration salt solution of WHO formula is recommended for oral rehydration therapy (ORT). Ringer's lactate is the ideal intravenous fluid for correction of severe dehydration due to diarrhoea. Antibiotic therapy is beneficial for cholera and shigellosis only. Antiparasitic agents are indicated only if amoebiasis or giardiasis is present. Antidiarrhoeals are of no benefit for the treatment of acute diarrhoea. Appropriate feeding during diarrhoea is recommended with beneficial outcome.

Records of all the diarrheal patients up to the age of 5 years who were admitted to and died in Dr. B.C. Roy Memorial Hospital for Children, Calcutta, between January and December 1990 were analyzed. The records were reviewed to assess the relative importance of three clinical types of diarrhea (acute watery diarrhea, acute dysentery and persistent diarrhea) as the causes of mortality. Annual hospital death rates of children suffering from acute watery diarrhea, dysentery and persistent diarrhea were 13.6%, 18.2% and 25.9%, respectively. Overall death rates in dysentery (p = 0.03) and persistent diarrhea groups (p < .00001) were significantly higher than watery diarrhea group. Maximum deaths occurred among children aged between 7 and 36 months in all categories of diarrhea. Shigella infected children had higher case fatality rate. In acute watery diarrhea, 30.9% cases were assigned to associated causes of death whereas the same could be assigned to 92.6% and 93.2% cases in dysentery and persistent diarrhea group, respectively. Deaths occurred in most of the cases who had bronchopneumonia as underlying cause, septicemia as immediate cause and protein calorie malnutrition as associated cause and these were most frequently associated in patients suffering from dysentery and persistent diarrhea. Only 2.0% children suffering from acute watery diarrhea had dehydration at the time of death. Significantly, a high percentage of deaths occurred among malnourished children who suffered from dysentery (54.4%) and persistent diarrhea. These data suggest that Diarrheal Disease Control Programme should also give emphasis on management of non watery, non-dehydrating type of diarrhea with complications.

Vibrio cholerae O139 was recovered from 28 of 79 children with acute watery diarrhoea. Clinically, they presented with watery diarrhoea (100%), vomiting (79%), abdominal cramps (61%), anorexia (61%), dehydration (100%), and absence of fever. Both clinical and blood biochemical parameters of these cases were similar to the illness caused by the new strain in adults. Hypoglycaemia was seen in 40% of those screened.

Previous studies have identified enteroadherent Escherichia coli that exhibit localized adherence, diffuse adherence and atypical diffuse adherence as diarrhoeagenic agents associated with infantile diarrhoea in Calcutta, India. In this study, a DNA probe specific for enteroaggregative adherence was used to determine the etiological significance of enteroaggregative E. coli in the causation of diarrhoea. From a total of 330 strains of E. coli recovered from 159 cases of acute secretory diarrhoea and 174 cases of invasive diarrhoea, 20 strains hybridized with the probe, whereas of the 25 E. coli strains recovered from 25 healthy controls only 1 strain hybridized with the probe. Of the 21 probe positive strains, 19 adhered to HeLa cells in the typical stacked-brick pattern while 2 strains recovered from 2 cases of secretory diarrhoea adhered to the glass surface in a hitherto undescribed formation which we have termed, based on the appearance, as the honey-comb pattern. The enteroaggregative E. coli strains identified in this study did not produce any conventional enterotoxins and were significantly associated with patients with secretory diarrhoea (10.7%) than with invasive diarrhoea (1.7%). The results of this study indicate that enteroaggregative E. coli play a causal role in acute secretory diarrhoea in this part of the world which lends credence to the involvement of a potent toxin in the pathogenesis of EAggEC mediated infections.

To determine the effect of a massive single oral dose of vitamin A (200,000 IU) supplementation on diarrhoea and acute respiratory infection (ARI), a double-blind placebo controlled trial involving 174 children under six years of age (excluding infants) was carried out in a Calcutta slum community. Ninety-one children received vitamin A supplementation (experimental group) and 83 children received a placebo (control group). All the children were followed up for six months by active fortnightly surveillance for occurrence of diarrhoea or ARI and their duration. There was no statistically significant difference in the incidence of diarrhoeal episodes or ARI. However, there was a significant difference (p < 0.05) in the average duration of diarrhoea per episode (2.1 vs. 3 days) between the experimental and control groups. Possible beneficial effects of a single oral dose of vitamin A supplementation on the incidence of diarrhoea and ARI could not be demonstrated in the present study.

Enteric infection still causes the highest global morbidity and mortality in children under 5 years old. While there have been impressive developments in the early treatment of diarrhea, adequate diagnostic techniques are not yet available. An international collaboration was conducted with the National Institute of Cholera and Enteric Diseases, Calcutta on the rapid diagnosis and prevention of diarrheal diseases. Forty to fifty per cent of the 780-bed Infectious Diseases Hospital is occupied by cases of diarrhea. Vibrio cholerae O1 continues to occupy a prominent position, and the prevalence in children up to 2 years is 30.9%. Accordingly, immuno-enzymatic detection of cholera toxin in stool was achieved. Bead enzyme-linked immunosorbent assay (ELISA) could successfully detect 40 pg/mL toxin within 4 h, but the detection rate of culture, bead ELISA and polymerase chain reaction (PCR) method was 72.2, 71.1 and 95.9%, respectively, indicating that PCR provides the most sensitive and specific assay for diagnosis of cholera directly from the stool of patients. Heat-stable enterotoxin (STa) is another virulence factor of gastroenteritis. Various monoclonal antibodies were established against it, and developed a competitive ELISA for the detection of STa producing strains. A DNA probe was also prepared, and genus vibrio was monitored. V. mimicus were found to be the reservoirs of STa among clinical vibrios. Various monoclonal antibodies against STa were also useful for the epitope mapping, providing information on the topology of toxin-host interaction.

A collection of 28 strains of Vibrio cholerae non-O1 isolated during a 3-year period (1989-1991) from hospitalised patients with acute diarrhoea in Calcutta, India, were examined with regard to virulence-associated factors. Of the 28 isolates (each representing a case), 18 were isolated as the sole infecting agent; the remaining 10 were recovered as co-cultures from cases infected with V. cholerae O1. Of the strains isolated in this study, 82% could be serotyped, with serovars O5 (32.1%), O11 and O34 (14.3% each) predominant. Serovars O7, O14, O34, O39 and O97 were associated exclusively with sole infections. Two strains of V. cholerae non-O1 produced anti-cholera toxin IgG-absorbable cholera toxin (CT). Both CT-producing V. cholerae non-O1 strains hybridised with the DNA probe specific for the zonula occludens toxin (ZOT) but none of the remaining 26 strains hybridised with the ZOT probe. The majority of the strains were cytotoxic for CHO, HeLa and Vero cells, with end-point titres of 4-512. Fewer strains produced a cytotonic effect, with end-point titres of 2-16. Of the 28 strains of V. cholerae non-O1 examined, 75%, 75%, 25% and 14.3% produced haemolysin that was active against erythrocytes of rabbit, sheep (Eltor haemolysin), chicken and man, respectively. Strains that produced a haemolysin active against both rabbit and sheep erythrocytes were dominant (35.7%). Ten (35.7%) of the 28 strains examined showed cell-associated haemagglutinating activity on human blood. Of the 10 strains, nine were isolated as sole pathogen and only one strain was associated with mixed infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Out of 539 acute diarrhoea cases studied, Vibrio mimicus was isolated as a sole pathogen in the faeces of 7 (1.3%) cases. The chief clinical presentations of the seven cases were watery diarrhoea and vomiting. Bloody diarrhoea was observed in 2 (28.5%), abdominal pain in 2 (28.57%) and fever in one (14.29) cases. All cases could be effectively treated with ORS except 3 (42.85%) cases who required IV Ringer's lactate. All V. mimicus strains isolated in the study were uniformly susceptible to tetracycline, chloramphenicol, norfloxacin and ciprofloxacin.

A total of 113 patients suffering from acute watery diarrhoea caused by the novel epidemic strain of Vibrio cholerae non-O1, currently assigned to a new serogroup O139, were investigated in order to determine the clinical presentation of the new epidemic strain causing outbreaks of cholera-like infection in the Indian subcontinent. Estimations of electrolyte concentration in serum and stool were also performed in a representative number of the above cases. The clinical features and blood and stool biochemical parameters of V. cholerae serogroup O139 diarrhoeal patients were indistinguishable from those in typical cholera, except for 44.3% cases infected by O139 had abdominal cramps. In view of the above, we propose to designate the disease caused by V. cholerae O139 as cholera.

The significance of Cryptosporidium as a causative agent of acute diarrhoea has been assessed in a year long hospital based study. A significantly higher detection of Cryptosporidium (P < 0.01) was observed in cases as compared to controls. Cryptosporidium was detected alone from 3% of acute diarrhoeal patients and from 5.5% in combination with other enteric pathogens. However, only 1.1% of control subjects were positive for Cryptosporidium. The highest detection rate of Cryptosporidium oocysts was in the first two years of life, in both cases and controls. No sex specific predilection for Cryptosporidium was observed in either the cases or controls.

Hospital acquired enteric infections were investigated by studying 3138 children under 5 years of age who were admitted without diarrhea in nine medical words of a pediatric hospital, Calcutta during the period between March and September 1987. Three hundred and twenty (10.2%) children developed nosocomial diarrhea during their hospital stay. Fecal samples from 178 nosocomial diarrhea, 345 hospitalized diarrhea cases, 178 hospital controls and 200 outpatient controls were collected for detection of established enteropathogens. There were no statistically significant differences in the detection of most of the enteropathogens from fecal samples of nosocomial diarrhea, hospitalized diarrhea and hospital controls. Enteric pathogens were detected at a higher frequency (statistically significant) from fecal samples of nosocomial diarrhea cases as compared to outpatient controls. This study highlights the importance of most of the enteropathogens like Shigella, Salmonella, rotavirus, enteropathogenic E. coli as the cause of hospital cross infection. This study reinforces the importance of developing preventive measures in order to reduce the frequency of illness.

An Australian tourist suffering from severe acute watery diarrhoea and dehydration due to Vibrio cholerae non-01 was studied. The V. cholerae strain isolated from the patient belonged to serovar 05. The organism did not produce any of the conventional enterotoxins including cholera-toxin (CT) or heat-stable toxins (NAG-ST) that are known to be associated with intestinal secretion. This report suggests that toxin(s) other than CT-like or NAG-ST may be involved in the pathogenesis of diarrhoea by some V. cholerae non-01 strains.

A highly sensitive bead enzyme-linked immunosorbent assay (bead ELISA) for detection of cholera toxin (CT) was evaluated for direct detection of CT from stool specimens of patients with acute secretory diarrhea. Of the 75 stool samples examined, 59 yielded biochemically, and serologically confirmed strains of Vibrio cholerae O1. The bead ELISA was positive for CT in stool supernatants in 50 (84.7%) of the 59 samples from which V. cholerae O1 was isolated. In addition, the bead ELISA was positive for three stool specimens which were negative by culture. The free CT present in 48 of the 50 stool samples positive by culture for V. cholerae O1 and for CT by bead ELISA was completely absorbed by anti-CT immunoglobulin G. All of the 59 strains of V. cholerae O1 biotype eltor isolated in this study produced in vitro CT. The concentration of CT present in the bead ELISA-positive stool samples ranged between 26 pg/ml and greater than 100 ng/ml. This evaluation study demonstrates that the bead ELISA is a sensitive and simple method for direct detection of CT in nonsterile stool samples, and we recommend routine use of this assay for detection of CT in stool samples and culture supernatants in clinical and reference laboratories.

One hundred eighty nine children suffering from different medical problems were admitted in two wards of a pediatric hospital in Calcutta during the period between November 18, 1985 and February 10, 1986. Amongst them, 36 children developed nosocomial diarrhea and rotavirus was detected from 80.5% of the cases. The nosocomial rotavirus diarrhea cases had lesser frequency of stools and only mild dehydration but the course of illness was longer in comparison to that of the hospitalized rotavirus diarrhea cases. There is a possibility of spread of infection via fomites, environmental surfaces and most likely mothers.

From 1985 to 1988, 857 children (aged between 1 day and 60 months) admitted to hospital with diarrhoea and 241 controls (aged between 5 days and 60 months) were examined for campylobacters and other enteric pathogens by means of conventional methods. The difference between the isolation rates of campylobacters in those cases in which no other enteric pathogen was found (4.8%) and controls (6.2%) was not significant (P greater than 0.05). Strains of Campylobacter jejuni/coli were isolated throughout the year with higher isolation rates during the summer and monsoon months. Mixed infections were very common. Watery diarrhoea (97.6% cases) was the most common clinical presentation of patients found to be infected solely by C. jejuni/coli. Most patients infected with campylobacters were mildly to moderately dehydrated. Biotype I of C. jejuni and C. coli was the dominant biotype associated with cases and controls. All strains of C. jejuni/coli, regardless of their source, were found to be sensitive to erythromycin. From this study, it appears that enteric infections with campylobacters among children in Calcutta are common but often asymptomatic.