NON-VIBRIO CHOLERA

A randomized controlled trial of glucose versus amylase resistant starch hypo-osmolar oral rehydration solution for adult acute dehydrating diarrhea

Background

Reduction of gross diarrhea rate in excess of that seen over time with intravenous therapy and appropriate antibiotics is not usually achieved by oral glucose-electrolyte rehydration therapy for cholera and cholera-like diarrheas.

Methodology and Principal Findings

This prospective randomized clinical trial at a tertiary referral hospital in southern India was undertaken to determine whether amylase resistant starch, substituting for glucose in hypo-osmolar oral rehydration solution, would reduce diarrhea duration and weight in adults with acute severe dehydrating diarrhea. 50 adult males with severe watery diarrhea of less than three days' duration and moderate to severe dehydration were randomized to receive hypo-osmolar ORS (HO-ORS) or HO-ORS in which amylase resistant high amylose maize starch 50g/L substituted for glucose (HAMS-ORS). All remaining therapy followed standard protocol. Duration of diarrhea (ORS commencement to first formed stool) in hours was significantly shorter with HAMS-ORS (median 19, IQR 10-28) compared to HO-ORS (median 42, IQR 24-50) (Bonferroni adjusted P, P_adj<0.001). Survival analysis (Kaplan-Meier) showed faster recovery from diarrhea in the HAMS-ORS group (P<0.001, log rank test). Total diarrhea fecal weight in grams (median, IQR) was not significantly lower in the HAMS-ORS group (2190, 1160-5635) compared to HO-ORS (5210, 2095-12190) (P_adj = 0.08). However, stool weight at 13-24 hours (280, 0-965 vs. 1360, 405-2985) and 25–48 hours (0, 0-360 vs. 1080, 55-3485) were significantly lower in HAMS-ORS compared to HO-ORS group (P_adj = 0.048 and P = 0.012, respectively). ORS intake after first 24 hours was lower in the HAMS-ORS group. Subgroup analysis of patients with culture isolates of Vibrio cholerae indicated similar significant differences between the treatment groups.

Conclusions

Compared to HO-ORS, HAMS-ORS reduced diarrhea duration by 55% and significantly reduced fecal weight after the first 12 hours of ORS therapy in adults with cholera-like diarrhea.

Trial Registration

Current Controlled Trials ISRCTN72841333

Failure of sanitary wells to protect against cholera and other diarrhoeas in Bangladesh

Within an area of Bangladesh in which the incidence of cholera was high, use of sanitary pipe wells did not protect against cholera or related non-cholera diarrhoeas because well users also used contaminated water sources regularly enough to maintain high infection-rates. Protection was found to correlate with education and wealth.

Enterotoxigenic Escherichia coli and idiopathic diarrhoea in Bangladesh

Faecal Escherichia coli from Bangalee patients with idiopathic diarrhoea were tested in the Chinese hamster ovary cell (C.H.O.) assay to detect production of thermolabile enterotoxin (L.T.). C.H.O-positive E. coli produce both L.T. and a thermostable toxin (S.T.). C.H.O.-positive strains were found in 19.2% of all cases and in 70% of the most severely ill patients with non-vibrio cholera. E. coli which produce S.T. alone were identified in a third of the C.H.O.-negative cases. Enterotoxigenic E. coli were found in 55% of inpatients with idiopathic diarrhoea and, if an aetiological role is confirmed, may be one of the commonest causes of tropical diarrhoea.

Three characteristics associated with enterotoxigenic Escherichia coli isolated from man

In Dacca, Bangladesh, potent enterotoxin-producing Escherichia coli were isolated from many hospital cases of acute cholera-like diarrhea. Enterotoxigenic (tox(+)) and non-enterotoxigenic (tox(-)) isolates of E. coli were used to investigate possible means of differentiating tox(+)E. coli from those (tox(-)) of the normal flora. The majority (81%) of the tox(+)E. coli studied were found to be negative for sucrose fermentation, 85% exhibited retarded growth in a peptone medium at pH 8.5, and 92% released large amounts of ammonium sulfate precipitable materials into culture supernatant fluids; 66.6% exhibited all three of these properties. For the tox(-) group the respective values were found to be 50%, 31%, and 34%; only 9.3% exhibited all three properties. These results indicate that it may be possible to use phenotypic characteristics other than antigenic composition and enterotoxin production for the identification of enterotoxigenic E. coli.

Acute undifferentiated human diarrhea in the tropics. II. Alterations in intestinal fluid and electrolyte movements

The nature and magnitude of fluid and electrolyte loss into the small intestine were defined by the marker perfusion technique in patients with acute undifferentiated diarrhea (AUD) in the tropics. The patients were divided into two groups according to their small bowel bacteriologic findings, namely those with a predominant Escherichia coli flora and those with a mixed flora. 11 normal subjects served as controls. Net jejunal fluid secretion occurred into the lumen in four of seven patients with E. coli flora and three of seven with a mixed flora. The magnitude of secretion in the jejunum was greater in the E. coli flora patients than in those with a mixed flora. Four E. coli patients and one mixed flora patient had net fluid secretion in the ileum, although the magnitude of secretion in this area was less than in the jejunum. Intestinal fluid had higher bicarbonate concentration in the ileum than in the jejunum but was isotonic in both regions. It resembled in composition fluid from the same region of intestine in normal individuals. Recovery of normal fluid and electrolyte absorptive function was usually complete in both jejunum and ileum by 6-8 days after onset of the disease. Increase in unidirectional flux rates for H(3)O and (24)Na occurred in acute E. coli flora diarrhea and returned to normal levels in recovery: increase in J(beta) (plasma to lumen flux) primarily accounted for the increase in fluid loss. Intestinal biopsy revealed no alterations in villous architecture.A relationship between small bowel fluid production and the presence of toxigenic strains of E. coli within the small bowel has been found for E. coli flora patients. In many respects this disease resembles acute cholera. The mixed flora group represents a less defined entity which requires further study.

Hemodynamic studies on cholera. Effects of hypovolemia and acidosis

The hemodynamic effects of hypovolemia and acidosis were studied in 23 patients with cholera. Studies were made before and during fluid replacement and administration of alkali.

The major hemodynamic abnormalities encountered before rehydration can be ascribed to a reduction in circulating blood volume. Hypovolemia was associated with a reduction in cardiac output, blood pressures, and central blood volume. Restoration of blood volume returned these variables toward normal.

The chief effect of acidosis appeared to be a redistribution of blood from the peripheral to the central circulation; consequently, central blood volume, lesser circulation pressures, and cardiac output were relatively well maintained despite hypovolemia. Fluid administration without correction of acidosis favored a disproportionate increase in central blood volume, while reduction in hydrogen ion concentration attending fluid replacement resulted in a more even distribution of the circulating blood volume and reduced the possibility of engorgement of the pulmonary bed.

It is postulated that this redistribution of blood stems from peripheral venoconstriction and a reduction in the capacity of venous reservoirs induced by acidosis.