Astroviruses as a cause of nosocomial outbreaks of infant diarrhea.

During a 16-month study period at a children's hospital, 32 children developed nosocomial gastroenteritis caused by astroviruses. Twenty-five of these occurred during 2 epidemic outbreaks in medical and surgical infants' wards. From the community, 13 confirmed cases were admitted during the study period. Both community-acquired and nosocomial cases occurred during autumn, winter and early spring. The attack rates during outbreaks ranged between 7 and 62% and were highest among children with underlying gastrointestinal diseases. Diarrhea and vomiting were the most common clinical manifestations. The median duration of symptoms was 4 days and that of virus excretion was 5 days. Hospital infection with astroviruses is common and usually affects children less than 2 years of age. The probable mode of transmission is spread via contaminated hands.

Experimental intestinal obstruction in rats. Studies on structure and disaccharidase activities.

An experimental model of congenital intestinal obstruction (CIO) was created in rats by means of fetal intrauterine surgery between the 16th and 20th days of gestation. By the use of a microsurgical technique areas at the mid-jejunum or the jejuno-ileal junction were infarcted by coagulation of mesenteric vessels. Gestation was terminated by Cesarean section within 24 hours before expected term to avoid cannibalism. The structure of the intestinal mucosal cells proximal and distal to the CIO at the light microscopy as well as the ultrastructure level was not changed indicating that the surgical method was successful. The activities of the brush border enzymes, maltase and lactase were significantly reduced distal to the obstruction as compared to controls. Proximal to the obstruction lactase was the only enzyme showing reduced activity in comparison to controls. These findings were not dependent on the localization of the obstruction or when it was performed and suggest that CIO causes selective changes of the biochemical properties of the cell membrane. The results are in agreement with the findings of disaccharidase activities in biopsies taken from human infants with CIO and point to the importance of a normal intestinal passage for the development of brush border enzymes.