Differences in intestinal humoral immunity between healthy volunteers from UK and Bangladesh.

BACKGROUND/AIMS: Intestinal morphology has been shown to vary geographically. The impact of this variation on gut mucosal humoral immunity is not well-studied. The technique of peroral whole-gut lavage (WGL) with nonabsorbable cleansing fluid can be utilized for the study of gut immune responses in health and disease. In this study, the WGL technique was employed to compare various gut humoral immune parameters in healthy volunteers from Dhaka in Bangladesh and Edinburgh, UK. METHODS: Eleven healthy individuals (all male, age range 18-32) from Dhaka and 12 healthy individuals (4 male and 8 female, age range 23-48) from Edinburgh underwent WGL with a polyethylene glycol electrolyte-based solution drunk at a rate of 1 l/h. The first clear effluent was collected and processed. An ELISA technique was used to measure total immunoglobulins (A, M and G) and antibodies to bacterial lipopolysaccharide (LPS: endotoxin) ovalbumin and eotaxin. Immunoturbimetry and radioimmunoassy techniques were used to measure protein (albumin and alpha-1 antitrypsin) and eosinophil cationic protein (ECP), respectively, in WGL fluid (WGLF). RESULTS: The total IgA, ECP and eotaxin concentrations in WGLF from the Dhaka group were significantly higher than those of the Edinburgh group (P < 0.03, P < 0.002 and P< 0.005 respectively). The IgA antibody level against the core oligosaccharide of bacterial LPS from several Gram-negative species was significantly higher in the Dhaka group compared to the Edinburgh group (P< 0.0001). Similarly, there was generally higher level of IgA antibody response against the various different LPS core structures of Escherichia coli in the Dhaka group, in particular significantly higher against R1, R3 and R4 LPS cores (P< 0.02, P< 0.03 and P< 0.01 respectively) compared to the Edinburgh group. In contrast to antibacterial antibodies, the IgA and IgM antibodies against ovalbumin were significantly lower in the Dhaka group (P< 0.001 and P< 0.003, respectively) compared to the Edinburgh group. CONCLUSIONS: This study on gut mucosal humoral immunity from two geographically distinct populations suggests that place of residence influences gut mucosal humoral immunity. This difference in stimulation of humoral immunity of the gut might explain different rates of inflammatory bowel diseases in developing and developed countries, and also provides a major challenge for the development of mucosally presented vaccine worldwide.

Effect of an energy-dense diet on the clinical course of acute shigellosis in undernourished children.

To date there have been few reports on the impact of dietary intervention on the clinical course of acute shigellosis. Current management of acute shigellosis is primarily focused on antibiotic therapy with less emphasis on nutritional management. In a randomised clinical trial, we examined the role of an energy-dense diet on the clinical outcome in malnourished children with acute dysentery due to shigellosis. Seventy-five children aged 12--48 months with acute dysentery randomly received either a milk--cereal formula with an energy density of 4960 kJ/l (test group) or a milk-cereal formula with energy of 2480 kJ/l (control group) for 10 d in hospital. In both milk-cereal formulas, protein provided 11 % energy. In addition, the standard hospital diet was offered to all children and all children received an appropriate antibiotic for 5 d. The mean food intakes (g/kg per d) in the test and control groups were: 112 (SE 2.28) and 116 (SE 3.48) on day 1; 118 (SE 2.72) and 107 (SE 3.13) on day 5; 120 (SE 2.25) and 100 (SE 3.83) on day 10. The mean energy intakes (kJ/kg per d) in the test and control groups respectively were: 622 (SE 13.2) and 315 (SE 11.3) on day 1; 655 (SE 15.1) and 311 (SE 7.98) on day 5; 672 (SE 14.7) and 294 (SE 11.1) on day 10. The food and energy intakes were mostly from the milk-cereal diet. There was no difference between two groups in resolution of fever, dysenteric (bloody and or mucoid) stools, stool frequency and tenesmus. However, vomiting was more frequently observed among the test-group children during the first 5 d of intervention (67 % v. 41 %, There was an increase in the mean weight-for-age (%) in the test group compared with the control group after the 10 d of dietary intervention (6.2 (SE 0.6) v. 2.7 (SE 0.4), In addition, resolution of rectal prolapse was better (26 % v. 8 %, in the test group v. control group after 5 d, and 13 % v. 6 %, after 10 d of dietary intervention. Supplementation with a high-energy diet does not have any adverse effect on clinical course of acute shigellosis and reduces the incidence of rectal prolapse in malnourished children.

Whole gut lavage fluid analysis : a minimally invasive method for study of mucosal immunity and inflammation.

Studies of intestinal mucosal immunity and inflammation are limited by the relative inaccessibility of most of the small intestine. Any new method of studying mucosal immunity and inflammation in patients should be minimally invasive, cost-effective, and provide information not readily available using current methods. Gaspari et al. (1) described gut lavage with 3 to 4 L of nonabsorbable, commercially available polyethylene glycol (PEG)-based bowel cleansing fluid as a method for analyzing human intestinal secretions for antibody content. Peroral gastrointestinal (GI) lavage is widely used to cleanse the GI tract prior to colonoscopy, barium enema examination, or colonic surgery. Whole gut lavage fluid (WGLF) therefore often becomes available without subjecting a patient to any additional investigation. This method is also often more acceptable to healthy volunteers than almost any other method of studying small intestinal secretions. Over the past decade, we have found that WGLFs from patients (both adults and children) suffering from a variety of intestinal diseases contain immunoglobulins (Igs) and antibodies, hemoglobin, plasma-derived proteins, cytokines, inflammatory cells, and their granule-derived proteins and growth factors (2,3). In this chapter, we describe our experience of the use of WGLF to study mucosal immunity and inflammation.

Early feeding of an energy dense diet during acute shigellosis enhances growth in malnourished children.

In a controlled clinical trial, we examined the effect of the short-term feeding of an energy-dense milk cereal formula in malnourished children with clinically severe dysentery due to acute shigellosis. Seventy-five malnourished children, aged 12-48 mo, passing blood or blood with mucous in the stool for < or = 96 h, were offered a hospital diet. In addition, study children (n = 36) were offered a milk-cereal formula with an energy of 5 kJ/g (an 11% protein diet); similarly, control children (n = 39) were offered a milk-cereal formula with an energy content of 2.5 kJ/g (an 11% protein diet). Patients were admitted to the metabolic ward of the Clinical Research and Service Centre, Dhaka, at the International Centre for Diarrhoeal Disease Research, Bangladesh. Patients were studied for 10 hospital days and were then followed up at home after 30 d. After 10 d of dietary intervention, children in the study group had a significantly greater increase vs. controls in weight-for-age (6 vs. 3%, P < 0.001) and in weight-for-height (7 vs. 3%, P < 0.001). Serum prealbumin concentrations were significantly higher (study vs. control) after 5 d (0.214 vs. 0.170 g/L, P = 0.01) and after 10 d (0.244 vs. 0.193 g/L, P = 0.006) of the study. Greater weight-for-age was sustained at home 1 mo after discharge (8 vs. 5%, P = 0.005) from the hospital. Similarly, higher weight-for-height was sustained 1 mo after discharge (8 vs. 5%, P = 0.01). During their stay at home, there was no dietary intervention. The results of this study suggest that short-term feeding of an energy-dense diet enhances growth in malnourished children with acute dysentery due to shigellosis.

Randomized, controlled, clinical trial of rice versus glucose oral rehydration solutions in infants and young children with acute watery diarrhoea.

A randomized clinical trial was carried out to compare a packaged ready-to-mix rice oral rehydration solution (ORS) to the standard glucose ORS for the treatment of childhood diarrhoea. Children were of either gender, aged 3-35 months, presenting with a history of watery diarrhoea for 72 h or less. The main outcomes examined were stool output, ORS intake, duration of diarrhoea and nutritional recovery during follow-up at 16 d of illness. Stool output in the first 24 h (106 vs 107 g kg(-1)), ORS intake in clinic (93 vs 102 ml per motion) and duration of diarrhoea (88 h vs 81 h) were similar in the two treatment groups. The few episodes that became persistent were similar (2%) in the two groups. The weight gain during follow-up was similar in the two ORS groups.

Hypo-osmolar sucrose oral rehydration solutions in acute diarrhoea: a pilot study.

Based on studies showing improved absorption of hypo-osmolar oral rehydration solutions (ORS) with reduced glucose and sodium concentration, a hypo-osmolar ORS with sucrose replacing glucose (sodium 60, potassium 15, chloride 60, citrate 5, sucrose 58 mmol l-1, calculated osmolality 198 mOsm kg-1) was compared with mildly hyperosmolar glucose ORS (WHO) in 46 children aged 6-30 months with acute diarrhoea and dehydration. In the hypo-osmolar sucrose ORS group (n = 18) faecal output was less by 30% during the initial 24 and 48 h compared with controls, suggesting better absorption. Sucrose may be a suitable alternative to glucose in an absorption-efficient hypo-osmolar ORS.

Maternal education and family income as determinants of severe disease following acute diarrhoea in children: a case control study.

In a case-control study among the urban poor of Dhaka, Bangladesh, the association of maternal education and family income with severity of disease due to diarrhoea in children was examined. After adjusting for family income, 7 or more years of school education was associated with 54% reduced risk of severe disease as indicated by the presence of dehydration. Income in the uppermost quartile of this population, independently of maternal education, was associated with 41% reduced risk of severe disease compared to the lowest quartile. In the logistic regression model the effect of maternal education remained high after adjustment for several confounders. Based on the concept that socioeconomic variables operate through a set of proximate variables it is contended that maternal education, independently of economic power, through its impact on disease from acute diarrhoea, favourably influences child survival.

Serum, breast milk, and infant antibody after maternal immunisation with pneumococcal vaccine.

Pneumococci are a leading cause of severe bacterial disease in infants and children world wide. A possible means of protecting infants in the first few months of life is immunisation of the mother during pregnancy. We prospectively assessed pneumococcal immunisation of pregnant women to determine the amount of pneumococcal antibody transmitted to the infants in serum and milk and the half-life of the passively acquired antibody. Healthy pregnant women in Dhaka, Bangladesh, were randomised to receive pneumococcal or meningococcal vaccine with routine prenatal tetanus immunisation at 30-34 weeks of gestation. Serum and breast milk specimens from the mothers and sera from infants were collected up to 22 weeks of age and assayed for specific serum IgG, IgG1, and IgG2 and for milk IgA antibodies to pneumococcal serotypes 6B and 19F. 55 mothers and 56 infants were followed from birth to five months. Women who received pneumococcal vaccine had geometric mean antibody increases of 2.6 and 3.4 to types 6B and 19F, respectively. The mean infant/maternal antibody ratios were 0.56 and 0.59 (range 0.11-1.46) for these serotypes. Infant cord antibody titres correlated with maternal titres. Infant/maternal IgG ratios correlated with the interval between immunisation and birth and were higher for specific IgG1 than for IgG2. Infants of pneumococcal vaccine recipients had geometric mean antibody concentrations of 6.8 and 7.5 micrograms/mL to serotypes 6B and 19F in cord blood; in cord blood and in all subsequent serum specimens the concentrations were 2-3 fold higher than in control infants. The median half-life of passive antibody was about 35 days; at five months of age 63-71% of infants of pneumococcal vaccine recipients had antibody concentrations greater than 0.15 micrograms/mL. Breast milk IgA antibodies for pneumococcal serotype 19F, but not for type 6B, were significantly higher in vaccine recipients up to five months after delivery. If maternal pneumococcal polysaccharide antibodies do not interfere with active immunisation of the infant with new glycoprotein conjugate pneumococcal vaccines, passive-active immunisation of infants can be a feasible strategy for developing regions.

Moraxella septicemia in children with diarrheal disease.

We report 10 cases of Moraxella septicemia associated with diarrheal disease. Their clinical presentations and outcomes are discussed. Recognition of the pathogenicity of these microorganisms in appropriate clinical setting should result in prompt and specific therapy.

Hypotonic oral rehydration solution in acute diarrhoea: a controlled clinical trial.

In a controlled trial, a hypotonic oral rehydration solution (ORS) (Na+67, K+20, Cl-66, citrate 7, glucose 89 mmol/l osmolality 249 mosmol/kg) was compared with a standard WHO-ORS (Na+90, K+20, Cl-80, citrate 10, glucose 111 mmol/l, osmolality 311 mosmol/kg) in 60 children aged 5-24 months with acute watery diarrhoea. In the hypotonic ORS group, stool frequency, proportion of children who vomited, ORS requirements and purging rate over 24-48 h were reduced by 33% (p = 0.01), 30% (p = 0.02), 21% (p = 0.067) and 21% (p = 0.03), respectively. The proportion of children who vomited and the purging rate over 48 h were reduced by 23% (p = 0.03) and 10% (p = 0.097), respectively. Serum electrolytes after 48 h were comparable. The beneficial effect of hypotonic ORS was most marked in, and largely contributed by, the subgroup negative for rotavirus.

Infectious agents causing acute watery diarrhoea in infants and young children in Bangladesh and their public health implications.

We studied the age specific distribution of enteropathogens in young children presenting at a large diarrhoeal diseases hospital in urban Bangladesh. A 5 per cent systematic sample was used to examine 1207 rectal swab specimens of children aged 1-35 months with acute watery diarrhoea. Variation in isolation rates of enteropathogens was observed in different age groups. Overall rotavirus (26 per cent) and Campylobacter (26 per cent) were the most common pathogens followed by enterotoxigenic Escherichia coli (15 per cent), Vibrio cholerae 01 (7 per cent), other Vibrios (9 per cent), Shigella (4 per cent), and Salmonella (< 1 per cent). In early infancy (1-5 months) more rectal swab specimens did not yield any enteropathogen compared to older children of 24-35 months old (44 v. 30 per cent). Rotavirus was most frequently detected (35 per cent) in children between 6 and 11 months old. Attendance of cholera cases at the hospital was alarmingly high in the third year of life (29 per cent). The study provided useful information that, in general, children under 2 years are predominantly infected with agents [rotavirus, Campylobacter, and enterotoxigenic Escherichia coli (ETEC)] for which antibiotic therapy is not usually indicated. These patients can be managed effectively with oral rehydration therapy and proper feeding. Knowledge of pathogens associated with more severe forms of diarrhoea may help in optimizing strategies for vaccination when suitable vaccines are available against enteric infections.

Multiple-drug-resistant Salmonella gloucester infections in Bangladesh.

We describe three different cases of extraintestinal infections caused by multidrug-resistant Salmonella gloucester from Bangladesh that were associated with bad prognoses. These clinical manifestations were not previously reported for S. gloucester.

Severity of cholera during concurrent infections with other enteric pathogens.

In a clinic-based case-control study in Bangladesh we evaluated whether children with diarrhoea due to V. cholerae O1 in association with other enteric pathogen(s) are likely to manifest more severe disease as indicated by development of moderate or severe dehydration. Children with moderate or severe dehydration were defined as cases and those with no dehydration were controls; both cases and controls had acute diarrhoea. A systematic sample of 268 dehydrated cases and 699 nondehydrated controls aged 1-35 months with acute watery diarrhoea of 6 days or less was included. In a multivariate analysis it has been shown that infection with Vibrio cholerae O1 in association with another diarrhoea pathogen (odds ratio = 7.07) was strongly correlated with status of dehydration than those with the V. cholerae O1 infection as a single pathogen (odds ratio = 3.63). Either group was associated with significant risk of dehydration. The results of the study suggest that more than one enteropathogen may be simultaneously involved in causing severe diarrhoea, and appropriate public health measures to reduce environmental contamination should be beneficia

An epidemic of cholera due to Vibrio cholerae O139 in Dhaka, Bangladesh: clinical and epidemiological features.

We describe the disease spectrum and socio-demographic and epidemiological features of an epidemic of cholera due to a new pathogen, Vibrio cholerae O139, in patients attending a very large hospital in the metropolitan city of Dhaka, Bangladesh. This hospital treats 70,000-90,000 patients a year with diarrhoeal diseases. A 4% systematic sample of 1854 patients attending from January to April 1993 were studied. Five hundred and two (27%) of the 1854 patients were culture positive for V. cholerae O139 and 63 (3%) were culture positive for V. cholerae O1 biotype El Tor. Patients with V. cholerae O139 were mainly adults with a short history of watery diarrhoea. Eight-three percent of patients had moderate to severe dehydration. All recovered except one 80-year-old man with compromised renal function who died. Seventy-eight percent of patients required initial intravenous rehydration followed by oral rehydration therapy with rice ORS; they also received tetracycline to reduce diarrhoea severity. Most patients were from urban slums with inadequate sanitation facilities and hygiene practices. The newly recognized V. cholerae O139 infection produced an epidemic of severe dehydrating diarrhoea indistinguishable from clinical cholera in a population which experiences two epidemic peaks of cholera in a year due to V. cholerae O1. Infection with the latter does not appear to confer any cross-protection from V. cholerae O139. The new pathogen suppressed, albeit temporarily, V. cholerae O1. Unlike other non-O1 serogroups of V. cholerae this new serogroup appears to have epidemic potential.

Common diarrhea pathogens and the risk of dehydration in young children with acute watery diarrhea: a case-control study.

The role of common diarrheal pathogens in dehydration was examined in children with acute watery diarrhea who attended the treatment center of the International Centre for Diarrhoeal Disease Research, Bangladesh, in Dhaka. Two hundred sixty-nine children with moderate or severe dehydration were matched with 700 children with no dehydration. Vibrio cholerae O1 infections were 5.5 times more likely to be associated with dehydration than in cases without this agent. No significant association could be found between the presence of enterotoxigenic Escherichia coli. Campylobacter jejuni, or rotavirus infection and dehydration. These results were obtained after simultaneously controlling for age, lack of oral rehydration therapy (ORT) at home, protein energy malnutrition, withdrawal of breast-feeding during diarrhea at home, poor housing, longer duration of diarrhea at home, and delay in reaching the treatment center. The cholera isolation rate was only 4.5% and thus explains only a small proportion of the cases of dehydration. In cholera-endemic areas, a strategy to prevent dehydration in small children is needed to ensure correct use of ORT at home, prompt referral, and the use of a suitable antibiotic when cholera is clinically suspected.

Breast feeding and oral rehydration at home during diarrhoea to prevent dehydration.

In a case-control study we evaluated the role of maternal behaviour, as reflected in maintenance of breast feeding and the use of oral rehydration therapy (ORT) at home during acute diarrhoea, in preventing dehydration in infants and young children. A systematic 5% sample was taken of all children aged 1-35 months attending the treatment centre of the International Centre for Diarrhoeal Disease Research, Bangladesh, with acute watery diarrhoea of six days or less between August 1988 and September 1989. There were 285 children with moderate or severe dehydration as cases and 728 with no dehydration as controls in the study. In a multivariate analysis using a logistic regression model we showed that withdrawal of breast feeding during diarrhoea was associated with a five times higher risk of dehydration compared with continuation of breast feeding during diarrhoea at home. Lack of ORT with either complete formula or a salt and sugar solution at home was associated with 57% higher risk of dehydration compared with receipt of a reasonable amount of ORT after controlling for several confounders. The confounding variables--that is, lack of maternal education, history of vomiting, high stool frequency, young age and infection with Vibrio cholerae 01--were also shown to be risk factors of dehydration. Health education programmes should promote continued breast feeding and adequate oral rehydration therapy for infants with acute diarrhoea at home.