Luc Chicoine

Randomized, controlled trial of antibiotic therapy for Escherichia coli O157:H7 enteritis.

We undertook a prospective, controlled study to evaluate the effect of trimethoprim-sulfamethoxazole in children with proven Escherichia coli O157:H7 enteritis on the duration fo symptoms, on fecal excretion of pathogen, and on the risk of progression to hemolytic-uremic syndrome. There was no statistically significant effect of treatment on progression of symptoms, fecal pathogen excretion, or the incidence of HUS (2/22 vs 4/25; p = 0.67). Our results suggest that a multicentric trial using rapid diagnostic methods to permit early randomization should be carried out.

794 YERSINIA ENTEROCOLITICA GASTROENTERITIS IN CHILDREN

Y. enterocolitica (YE) is the second commonest cause of bacterial gastroenteritis (GE) in children in the Montreal area. The purpose of this study is to define prospectively the incidence of YE GE, duration of carriage, serological response, communicability in households, and effect of antimicrobial therapy. Clinical, bacteriologic and serologic surveillance was performed on index cases (IC) and their family members until all members of the family had 3 consecutive negative stools. During the first 6 mo of the study 96 IC were identified from 2531 ill children. In 31 IC whose clinical and epidemiologic data were available, diarrhea (100%), fever (71%) and abdominal pain (61%) were major symptoms with mean duration (D) of 16, 4 and 9 days respectively. D of excretion of YE was 4.5 wks (range 2-9). Paired sera were available from 25 IC; all but 2 (both under age 4.5 mo) showed a serologic response. The geometric mean titer of the 1st serum from those ≥1 yr (18) was 635, compared to 100 for those ≥1 yr (7). Intrafamilial spread was documented by at least 2 of 3 criteria (clinical, bacteriologic, or serologic) in 7 of 25 families, involving 4 of 13 children and 3 of 53 adult household contacts. It is too early to evaluate the effect of therapy.Our findings indicate that (1) YE is a frequent cause of GE in children; (2) YE GE is followed by “O” type-specific antibody response in children ≥1 yr of age; and (3) intrafamilial spread is often asymptomatic.

Cefotaxime versus Chloramphenicol for Ampicillin-Resistant Haemophilus influenzae Meningitis

Cefotaxime (Jacobs et at. 1985;Odio et al. 1986) and other third generation cephalosporins (Aronoff et al. 1984;Barson et at. 1985;Chartrand et al. 1984; Congeni 1984; Del Rio et al. 1983; Kaplan et at. 1984; Rodriguez et at. 1986) were proposed as alternatives to ampicillin and chloramphenicol as initial therapy for suspected bacterial meningitis in infants and children, and even for culture-proven meningitis, irrespective of the ampicillin susceptibility of the micro-organism. The superiority of these cephalosporins over conventional therapy resides particularly in their very potent activity against t/-Iactamase-producing and ampicillin-resistant Haemophilus influenzae (Lapointe & Beyeler 1985; Neu 1982, 1985). Unfortunately, the overall clinical experience with these cephalosporins in meningitis due to ampicillin-resistant H. injluenzae is small. The combination of ampicillin and cefotaxime is used routinely at this centre as initial therapy (~ 48h) for childhood meningitis, pending bacterial isolation and sensitivity testing. Cefotaxime is subsequently limited to patients suffering from meningitis due to ampicillin-resistant H. influenzae. The present study includes 36 such cases identified over a 4-year period and treated with cefotaxime. The clinical outcome in these patients was compared with that in 26 other ampicillin-resistant meningitis patients treated in the past with chloramphenicol. 1. Methods

Cefotaxime versus Chloramphenicol for Ampicillin-Resistant Haemophilus influenzae

Cefotaxime (Jacobs et at. 1985;Odio et al. 1986) and other third generation cephalosporins (Aronoff et al. 1984;Barson et at. 1985;Chartrand et al. 1984; Congeni 1984; Del Rio et al. 1983; Kaplan et at. 1984; Rodriguez et at. 1986) were proposed as alternatives to ampicillin and chloramphenicol as initial therapy for suspected bacterial meningitis in infants and children, and even for culture-proven meningitis, irrespective of the ampicillin susceptibility of the micro-organism. The superiority of these cephalosporins over conventional therapy resides particularly in their very potent activity against t/-Iactamase-producing and ampicillin-resistant Haemophilus influenzae (Lapointe & Beyeler 1985; Neu 1982, 1985). Unfortunately, the overall clinical experience with these cephalosporins in meningitis due to ampicillin-resistant H. injluenzae is small. The combination of ampicillin and cefotaxime is used routinely at this centre as initial therapy (~ 48h) for childhood meningitis, pending bacterial isolation and sensitivity testing. Cefotaxime is subsequently limited to patients suffering from meningitis due to ampicillin-resistant H. influenzae. The present study includes 36 such cases identified over a 4-year period and treated with cefotaxime. The clinical outcome in these patients was compared with that in 26 other ampicillin-resistant meningitis patients treated in the past with chloramphenicol. 1. Methods

Immune response to verotoxin 1 and 2 in children with Escherichia coli O157:H7 hemorrhagic colitis and classic hemolytic uremic syndrome.

OBJECTIVES To compare neutralizing antibody titres against verotoxin (vt)-1 and vt-2 between children with uncomplicated hemorrhagic colitis (hc) and those with classic hemolytic uremic syndrome (hus). vt antibody titres were also compared in children with hc who received trimethoprim-sulfamethoxazole with those who did not. DESIGN Prospective study. SETTING Tertiary pediatric hospital. POPULATION STUDIED Children with hc (n=41) or classic hus (n=12). INTERVENTIONS Serum antibodies against vt-1 and vt-2 were determined by quantitative neutralization. MAIN RESULTS Antibodies were detected in 40% (21 of 53) of serum samples for vt-1 and in 100% (53 of 53) of samples for vt-2. A positive immune response, defined as a fourfold increase in vt antibody titres or as a single titre of 1/64 or greater, was found in 0% (0 of 12) of patients with hus compared with 7% (three of 41) of those with hc for vt-1 (P=0.4); and in 17% (two of 12) of patients with hus compared with 22% (nine of 41) of those with hc for vt-2 (P=0.3). The rate of seroconversion against either vt-1 or vt-2 was comparable in treated and untreated patients with uncomplicated hc. CONCLUSIONS There was no evidence that neutralizing antibody levels against vt-1 or vt-2 in classic hus or after antibiotic therapy are substantially different from those in patients with uncomplicated hc.