Norovirus as the cause of medically attended gastroenteritis: a hospital-based experience.

Gastroenteritis remains an important cause of morbidity and mortality worldwide. With the introduction of vaccines against rotavirus, interest has shifted to understanding the epidemiology of norovirus (NoV). While the importance of NoV in gastroenteritis outbreaks is well established, its role in sporadic gastroenteritis is less known. To better define the role of NoV as a cause of sporadic gastroenteritis we investigated its prevalence in the patients seen in our paediatric hospital with special emphasis on its seasonal and age distribution. Over a 12-month period discarded stool specimens submitted to our paediatric hospital for testing of an infectious aetiology were retrieved and additionally tested for NoV by real-time reverse transcriptase-polymerase chain reaction; demographical and clinical information were also obtained. Overall, NoV was the single most commonly identified pathogen and found in 68/892 (7·6%) total specimens or 68/258 (26%) of pathogen-positive specimens. The highest rates of NoV were detected in children aged 6 months to 4 years (50/332, 15·1%) and presenting between October and January (46/314, 14·7%). NoV has become the main cause of gastroenteritis in our paediatric population.

Acute gastroenteritis.

Acute gastroenteritis represents a frequent cause of morbidity and mortality among children in the developing world as well as morbidity in the developed world. Despite the large number of potential etiologic agents, management of gastroenteritis is uniform and aimed to prevent the two major complications, dehydration and malnutrition. Current guidelines emphasize the use of oral rehydration and the early reintroduction of age-appropriate foods. These guidelines are reviewed here, the underlying principles discussed, and practical points provided.

Clinical trial of modified whole milk, lactose-hydrolyzed whole milk, or cereal-milk mixtures for the dietary management of acute childhood diarrhea.

A randomized, double-masked clinical trial was completed to compare the effects of four dietary regimens for the nutritional management of 116 Peruvian children between 3 and 24 months of age with acute diarrhea. Diets consisted of a modified whole milk formula (group M), a lactose-hydrolyzed milk formula (HM), wheat noodles and whole milk (N-M), or wheat noodles and lactose-hydrolyzed whole milk (N-HM), all offered in amounts up to 55 kcal/kg body weight/day for the first 2 days of treatment and up to 110 kcal/kg/day for 4 days thereafter. The clinical characteristics of the patients in each group were similar initially. Treatment failure rates in the two milk groups combined (M = 14.3%, HM = 20.0%) were greater than in the two noodle-milk groups combined (N-M = 3.4%, N-HM = 3.4%), p = 0.03. The average stool outputs by children in both M groups (range 40-66 g/kg body weight per day on all study days) were consistently greater than those by children in both N-M groups (range 29-50 g/kg/day). The differences by dietary group were statistically significant on days 3 and 4 (p less than 0.04, analysis of variance). The estimated median durations of illness [and 95% confidence limits (CL)] in each milk group (M = 138 h, CL: 88-214; HM = 113 h, CL: 75-170) were significantly greater than in each noodle-milk group (N-M = 52 h, CL: 35-76; N-HM = 67 h, CL: 45-100), p less than 0.001-0.071. In this group of patients, noodle-milk mixtures produced fewer treatment failures, lower fecal outputs, and shorter durations of diarrhea than did milk alone, regardless of the lactose contents of the respective milks or mixed diets. Small differences in intestinal absorption and changes in body weight by dietary group that were identified were of minor clinical importance during the short duration of study. Thus, the noodle-milk diets employed during this study were safer than the milk diets for the dietary management of children with acute diarrhea.

Prediction of total daily fecal excretion during acute childhood diarrhea.

Clinical data from 133 male patients between 3 and 36 months of age were reviewed to identify factors that could predict high rates of fecal excretion during acute diarrhea. Diarrheal severity after hospitalization was measured by separate 4-h quantitative collections of feces during 6 days: the number of these 4-h collection periods with any stool output was used as an estimate of the number of bowel movements each day. The number of 4-h periods with any stool output was highly correlated with total fecal excretion expressed as grams per kilogram of body weight per day (p less than 0.001). The age of the patient, type of diarrhea, and type of diet had little effect on the relationship between stool "number" and amount. The number of bowel movements, as estimated during this study, was a highly sensitive (greater than 90%) and reasonably specific (greater than 70%) predictor of children at risk of high fecal excretion rates (greater than 50 g/kg/day or greater than 100 g/kg/day) during acute diarrhea.

Effect of continued oral feeding on clinical and nutritional outcomes of acute diarrhea in children.

One hundred twenty-eight nonmalnourished male patients between 3 and 36 months of age were randomly assigned to receive one of four lactose-free dietary treatments to determine the effect of dietary therapy on the severity and nutritional outcome of diarrheal illness. Group 1 received a formula diet composed of casein, sucrose, dextrin with maltose (Dextri-Maltose), and vegetable oil to provide 110 kcal/kg body weight/d (CSO-110). Group 2 received CSO to provide 55 kcal/kg/d (CSO-55) for 2 days and then CSO-110. Group 3 received only oral glucose-electrolyte solution (GES) for 2 days, CSO-55 for the next 2 days, and then CSO-110. Group 4 received the same diets as Group 3 except that only intravenous GES was used for the first 2 days. The GES maintenance solutions provided 24 to 30 kcal/kg/d. Therapeutic success rates were similar among dietary groups, ranging from 90% to 97%. Fecal excretion was initially lower in group 4 (P less than 0.05) but was similar initially among groups treated orally and among all four groups beginning on day 3. Net apparent absorption of nitrogen, fat, carbohydrate, and total energy; retention of nitrogen; and increments in body weight, arm circumference, and skin-fold thickness were positively related to the amounts of dietary energy consumed. Thus continued oral feeding with the CSO diets during the early phase of therapy yielded improved nutritional results.

The role of the carrier in treatment failures after antibiotic for group A streptococci in the upper respiratory tract.

During a prospective study of endemic group A streptococcal upper respiratory tract infection and the streptococcal carrier state, we investigated persistence of group A streptococci after treatment with recommended doses of antibiotics. We evaluated clinical findings, culture results, and streptococcal antibody responses at the acute-stage clinic visit and at convalescent-stage visits 3 and 8 weeks later. Data from 280 children ill with pharyngitis and their family contacts were analyzed (mean age 13.3 years); 129 individuals (46%) had group A beta-hemolytic streptococci isolated at the initial visit. Despite antibiotic treatment, group A streptococci were not eradicated from the upper respiratory tract of 34 (26%) of the 129 culture-positive individuals. Thirteen of the 34 (38%) required a second course of antibiotic therapy before the infecting serotype was eradicated, but a majority, the remaining 21 (62%) patients, were not bacteriologically cured despite repeated courses of antibiotics. Streptococcal antibody data suggested that the majority of the treatment failures were streptococcal carriers. Only 5% of asymptomatic individuals with a positive culture for group A streptococci demonstrated an antibody rise. These bacteriologic and serologic data document that it usually is unnecessary to retreat asymptomatic convalescent individuals having throat cultures persistently positive for group A streptococci, since these individuals seldom represent true streptococcal infection.

Risk of bacteremia after endotracheal intubation for general anesthesia.

Blood cultures were obtained before and after endotracheal intubation to assess the risk of bacteremia associated with this procedure and to evaluate the need for prophylactic antibiotics to prevent bacterial endocarditis in patients with structural heart disease requiring general anesthesia. Blood cultures were obtained immediately before intubation and two and ten minutes after intubation in 50 individuals without evidence of structural heart disease who required general anesthesia for elective surgery. Of 32 who had orotracheal intubation, only one demonstrated postintubation bacteremia; of 18 individuals who had nasotracheal intubation, none had evidence of bacteremia. These data suggest that in healthy individuals undergoing endotracheal intubation under direct vision the risk of bacteremia is quite small (about 2%).

Failure of penicillin to eradicate group A streptococci during an outbreak of pharyngitis.

In an outbreak of group A streptococcal pharyngitis in a semi-closed community, 42 (25%) of 169 courses of antibiotic therapy failed to eradicate the organism. 16 (19%) of 85 individuals treated with intramuscular benzathine penicillin G and 9 (19%) of 47 patients treated with an oral antibiotic (penicillin V or erythromycin) continued to harbour the same serotype of group A streptococcus. 12 (48%) of 25 persons remained treatment failures after re-treatment; even after a third course of treatment 5 of 12 (42%) still harboured the organism. Neither antibiotic resistance of the epidemic strain nor reacquisition of the organism from contacts could be implicated as causes. The data suggest that many who did not respond to treatment were streptococcal carriers and raise the possibility that it is more difficult to eradicate the organism from the carrier than from the acutely infected individual.

The immunologic response to group A streptococcal upper respiratory tract infections in very young children.

The immunologic responses to streptolysin O and streptococcal deoxyribonuclease B were evaluated in children with group A streptococci recovered from the upper respiratory tract to re-examine the hypothesis that a limited capacity to respond to group A streptococcal infection may explain the rare occurrence of acute rheumatic fever in very young children. ASO and anti-DNase B titers were determined on serial bleedings from a total of 301 individuals (52 less than or equal to 3 years; 249 older than 3 years). Very young children with group A streptococcal upper respiratory tract infections had an immunologic response to SO greater than the response in older children as reflected by the magnitude of the antibody rise, and comparable to the ASO response in older children as measured by the percentage showing a significant titer rise. Similar analyses of the anti-DNase B responses showed the response in young children to be comparable to those of the older group. Clinical manifestations of group A streptococcal upper respiratory tract infection in very young children differ from those observed in older children and have not changed significantly in the past several decades. These data suggest that the infrequent occurrence of acute rheumatic fever in very young children is not due to a difference in antibody response to streptolysin O or streptococcal DNase B.