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This prospective study was undertaken to study the occurrence of histologic chorioamnionitis and determine its association with prematurity; and to assess whether colonization of the genital tract of pregnant women by genital mycoplasmas or Chlamydia trachomatis is a risk factor for histologic chorioamnionitis. A total of 268 women with singleton pregnancies of over 26 weeks gestation were subjected to high vaginal cultures of genital mycoplasmas and endocervical specimens for chlamydia antigen. Placental histopathology was performed on multiple sections. Histologic chorioamnionitis was documented in 22.4 per cent (60/208) placentae. Genital tract colonization with Ureaplasma urealyticum or C. trachomatis was not a risk factor for histologic chorioamnionitis. Neonates born in association with histologic chorioamnionitis had a mean birth weight 111 g lower than those born without this lesion (2626.9 +/- 702 g vs 2737.8 +/- 500 g, NS). The relative risk (95% confidence interval) of prematurity in the presence of histologic chorioamnionitis was 1.49 (0.87-2.53). Analysis of linear trend in proportions for prevalence of histologic chorioamnionitis with decreasing gestation showed a significant association (P = 0.047, 1-tail). These results taken together suggest that histologic chorioamnionitis may be a risk factor of prematurity, but of only a modest magnitude.

Diarrhoea that begins acutely but lasts longer than two weeks is defined to be persistent. Revised estimates in developing countries including India showed that acute diarrhoea accounts for 35 per cent, dysentery 20 per cent and non-dysenteric persistent diarrhoea (PD) for 45 per cent of total diarrhoeal deaths. PD also often changes marginal malnutrition to more severe forms. Factors that increase the risk of acute diarrhoea becoming persistent have been identified in India and other developing countries. These include antecedent malnutrition, micronutrient deficiency particularly for zinc and vitamin A, transient impairment in cell mediated immunity, infection with entero aggregative Escherichia coli and cryptosporidium, sequential infection with different pathogens and lack of exclusive breast feeding during the initial four months of life particularly use of bovine milk. Several issues regarding the management of persistent diarrhoea in hospitalized children in India have been resolved. Diets providing modest amounts of milk mixed with cereals are well tolerated. In those who fail on such diets providing carbohydrate as a mixture of cereals and glucose or sucrose hasten recovery. The role of antimicrobial agents and individual micronutrients in PD is currently being investigated. A management algorithm appropriate for India and other developing countries has been developed and found to substantially reduce case fatality in hospital settings to about 2-3 per cent. Recent epidemiological and clinical research related to persistent diarrhoea is also reviewed.

The ability of HEp-2 cell adherent Esch. coli of aggregative phenotype (EA-Agg EC) to cause diarrhoea and to colonize the bowel of rabbits was studied. Thirty six rabbits were challenged with one of three EA-Agg EC strains (F23A; H766C and F17A-15, 3 and 3 rabbits respectively) or a control strain (K12-15 rabbits) in reversible ileal-tie in adult rabbit diarrhoea (RITARD) model. The animals were sacrificed 72 h post challenge. Severe diarrhoea occurred in greater number of F23A challenged rabbits than the controls (P < 0.05). Mucosal cultures from proximal and distal small intestine and colon yielded about 1000 times more Esch. coli in the test than control rabbits (P < 0.001 in each case). EA-Agg EC were consistently grown from mucosa in the test rabbits who commonly showed mild to moderate villous stunting and grade + to nuclear fragmentation (karyorrhexis) in the small and large bowel epithelium. The control animals had either normal villi or very mild villous stunting. Results comparable to F23A were obtained with the other two EA-Agg EC strains tested in a smaller number of animals.

The present study describes a nonisotopic DNA-DNA hybridization assay for the detection of enterotoxigenic Escherichia coli (ETEC) in which the probes were labelled with the hapten molecule digoxigenin and after hybridization, DNA hybrids were detected by antidigoxigenin alkaline phosphatase conjugate. A blinded study carried out on a battery of enterotoxigenic and nonenterotoxigenic Esch. coli by dig-probe hybridization assay were compared with the results of a radiolabelled toxin gene probe hybridization assay (performed earlier). The three digoxigenin labelled probes gave a 100 per cent specificity and sensitivities of 95.45, 100 and 100 per cent for LT, STh and STp respectively. These results were comparable to those with the radioactive probes.

Esch. coli strains manifesting localised (17), diffuse (8) or aggregative (17) phenotypes of adherence to HEp-2 cells were tested for their ability to adhere to human enterocytes isolated from duodenal biopsies of adult volunteers to obtain further evidence of their enteropathogenecity. Esch. coli strains H10407+; CFAI+ and LT+ STp+ STh+, F 294 B; a localised adherent strain positive with entero-adherent factor probe reported previously to attach to small intestinal enterocytes and F 582 C; LT- STp+ STh+ were the positive controls: H10407P (CFAI- mutant of H10407+) and K12 served as negative control strains. Adherence of variable degree was seen with 35.3 per cent of enteroaggregative Esch. coli (EAggEc) and with 58.8 per cent of enteroadherent Esch. coli localised (EAEC-L); EAEC-diffuse (EAEC-D) did not adhere to the human enterocytes. The possibility that EAgg EC and diffuse phenotypes may adhere better to lower small intestine or the large intestine, needs to be investigated.

Brush border lactase, sucrase and glucoamylase activities were assessed in jejunal mucosal biopsy specimens from 34 children (median age 11 months; range 1.5-38) having protracted diarrhoea with failure to thrive and 8 well nourished children with normal jejunal mucosal histology (median age 10.2 months; range 2-37). All enzymes showed progressive decrease in activity which was directly in relation to increasing degree of mucosal injury (P less than 0.002). Lactase was significantly reduced even in patients with protracted diarrhoea and normal mucosa (P less than 0.05). Glucoamylase and sucrase were significantly reduced only in the presence of mucosal injury (P less than 0.01). Our data suggest that most children with protracted diarrhoea may not tolerate lactose containing feeds and may need lactose-free diets preferably based on starch. A small number of children with protracted diarrhoea, who have severe mucosal injury may not be able to handle even starch and may require diets based on short chain glucose polymers. The findings of this study, need to be corroborated with well-controlled metabolic balance studies.

A rural cohort of 507 children, less than 3 yr of age was kept under weekly surveillance for 12 months, for morbidity due to diarrhoea. Stool specimens for rotavirus detection were obtained in 346 of the 360 diarrheal episodes occurring in 354 children and in 211 children without diarrhoeal symptoms. Rotavirus was detected by an ELISA test in 4 per cent of children with diarrhoea and 6.6 per cent of control subjects. Viral genome RNA was extracted by phenol chloroform method from all the positive samples and analysed by polyacrylamide gel electrophoresis followed by silver staining. All the strains isolated, exhibited the same electropherotype with a 'long' RNA migration pattern. This result contrasts with the genomic variability amongst rotavirus strains usually observed in different settings.

A commercial latex agglutination (LA) test was compared with ELISA and direct electron microscopy (EM) for detection of rotavirus antigen in 93 stool specimens obtained from as many children with acute gastroenteritis. Seventy one specimens (76.3%) were either positive or negative with all the three techniques, while 22 (23.7%) gave contradictory results. Only 1 sample was positive by LA test but not with ELISA or EM. The sensitivity of LA test and EM was 62.5 per cent (30 of 48) and 75 per cent (36 of 48); the corresponding specificity being 97.7 per cent (44 of 45) and 100 per cent (45 of 45) respectively. ELISA was more sensitive than the LA test and EM for detection of rotavirus antigen. LA test which is highly specific and a rapid method, may be useful in certain situations but its low sensitivity makes it unsuitable for use in routine clinical practice.