Human rotavirus (HRV) type 1 or 2, adenovirus, or non-cultivatable 27 nm virus-like particles were demonstrated by electron microscopy and/or rotavirus ELISA in fecal samples from 45.5% of 604 gastroenteritis inpatients, 25.0% of 200 gastroenteritis outpatients and 6.0% of 812 control subjects, all sampled at Children's Hospital National Medical Center. Washington, DC. Rotaviruses were the most common pathogens detected as 39% and 22% of gastroenteritis inpatients and outpatients, respectively, shed HRV. About three-fourths of the rotaviruses were type 2, which was prevalent during five successive epidemic years from January, 1974, through June, 1978. HRV type 1 was detected in the last four successive epidemic years and represented nearly half of the HRV infections observed among gastroenteritis inpatients during the year 1977--1978. Both rotavirus serotypes were detected most often in the month of January, when 71% of 123 gastroenteritis inpatients and 62% of 34 gastroenteritis outpatients shed one of these viruses. Uncultivatable adenoviruses were detected significantly more frequently in stools from patients with gastroenteritis (3.9%) than from control subjects (0.6%), suggesting that these viruses played a role in acute enteric disease. The frequency of detection of 27 nm particles was not significantly different in gastroenteritis and control patients. Numerically, HRV infection was detected most often in gastroenteritis inpatients who were 10 through 12 months of age. The group of gastroenteritis inpatients with the highest percentage of HRV infection was 13 through 15 months of age. The excess of type 2 HRV infection relative to type 1 infection was especially large in those aged 7 through 24 months. Lower socioeconomic status or greater crowding appeared to be associated with the occurrence of rotavirus infection earlier in life and earlier in the epidemic year.

Enzyme-linked immunosorbent assay (ELISA) has proven to be a useful assay system for the direct detection of infectious agents. However, when the usual color-producing substrates are employed, relatively large amounts of substrate must be hydrolyzed by the bound enzyme before detection can be achieved. We attempted to improve the sensitivity of ELISA by utilizing a substrate that yields a fluorescent product on enzyme action. The enzyme-linked fluorescence assay (ELFA) based on this principle was approximately 100 times more sensitive than the corresponding ELISA or radioimmunoassay for the detection of human rotavirus in a standard stool suspension. In addition, the ELFA for human rotavirus was capable of detecting antigen in six specimens that were negative by ELISA. Five of these specimens were obtained late in the course of confirmed rotavirus infections. ELFA provides a simple, reliable, ultrasensitive method for the rapid detection of viral antigen.

The clinical characteristics of disease due to enterotoxigenic Escherichia coli (ETEC) were determined in 88 adult males admitted to a hospital in Dacca, Bangladesh, with moderate to severe dehydration. Persons infected with ETEC strains producing both heat-labile toxin (LT) and heat-stable (ST) toxin had more dehydration and acidosis, longer duration of illness, and greater stool volume than persons infected with strains producing only ST. Tetracycline therapy, evaluated in 63 cases, resulted in slightly earlier termination of illness in patients with LT-ST strains but had no effect on illness in the patients with ST strains. In both groups of patients tetracycline shortened the duration of excretion of organisms. Because of its limited effectiveness and the generally excellent response of ETEC diarrhea to rehydration therapy alone, tetracycline is not warranted for use in treatment of ETEC diarrhea in adults in this population.