Single-dose Intravenous Ondansetron in Children with Gastroenteritis: A Randomized Controlled Trial.

OBJECTIVE: To evaluate the efficacy of ondansetron for the treatment of vomiting and thus reducing the need for intravenous (IV) rehydration in children with gastroenteritis. DESIGN: Double-blind, placebo-controlled, randomized trial. SETTING: Pediatric ward of An Giang General Hospital, South Vietnam, between December 2013 and June 2014. PARTICIPANTS: 61 inpatient children (age 11-60 mo) suffering from gastroenteritis with vomiting. Exclusion criteria were: underlying chronic conditions, immunodeficiency, malnutrition or history of allergy to ondansetron. INTERVENTION: Single bolus of IV ondansetron at a dose of 0.2 mg/kg or placebo. OUTCOME MEASURES: Proportion of patients who needed IV rehydration, proportion of patients with cessation of vomiting, amount of oral rehydration solution intake, duration of diarrhea and the length of hospital stay. RESULTS: After drug administration, 22 (73%) of the 30 patients in the ondansetron group had complete cessation of vomiting compared with 7 (23%) of the 31 patients in the placebo group (RR 0.32; 95% CI 0.16 to 0.63, P<0.001). 3 (10%) patients in the ondansetron group required IV rehydration as compared with 12 (39%) in the placebo group (RR 0.51; 95% CI 0.33 to 0.79, P=0.009). The median amount of oral rehydration solution intake in 24 hours was significantly greater in the ondansetron group (450 mL vs 350 mL, P=0.019).The duration of diarrhea and the length of hospital stay were not different between the two groups. CONCLUSIONS: In hospitalized children having gastro-enteritis associated with emesis, ondansetron is effective in the cessation of episodes of vomiting and in lowering the rates of IV rehydration, without reducing the duration of diarrhea and hospital stay.

A prospective cohort study of dengue infection in schoolchildren in Long Xuyen, Viet Nam.

A dynamic school-based cohort of 2-15 year-olds was established in Long Xuyen, Viet Nam to provide epidemiological data for a dengue vaccine efficacy trial. Active surveillance of febrile episodes identified clinically-suspected dengue and acute and convalescent sera were collected. IgG seroconversion between annual seroprevalence surveys identified sub-clinical infections. In 2004, 2190 children were enrolled with 3239, 3146, and 3081 present each year from 2005 to 2007 consecutively. In all, 627 children had a total of 690 clinically-suspected dengue episodes (394 hospitalisations, 296 outpatients) with 284-310 (41.2-45.0%) laboratory-confirmed depending on testing. Dengue serotype 2 was predominant in 2004 and 2005, and serotype 1 in 2006 and 2007. The acute dengue disease incidence rate per 1000 person-years ranged from 16.9 in 2005 to 40.4 in 2007. The average annual incidence of primary dengue infection (IgG seroconversion in previously naïve children) was 11.4% and the symptomatic to asymptomatic primary infection ratio ranged from 1:3-1:6. Study withdrawal rate, a feasibility indicator for conducting efficacy trials, was low: 4.2% per year when excluding children who changed schools. Our 2004-2007 results confirm the high transmission of dengue in children in Long Xuyen and demonstrate the suitability of this study site for a large scale efficacy trial.

Antimicrobial drug resistance of Salmonella enterica serovar typhi in asia and molecular mechanism of reduced susceptibility to the fluoroquinolones.

This study describes the pattern and extent of drug resistance in 1,774 strains of Salmonella enterica serovar Typhi isolated across Asia between 1993 and 2005 and characterizes the molecular mechanisms underlying the reduced susceptibilities to fluoroquinolones of these strains. For 1,393 serovar Typhi strains collected in southern Vietnam, the proportion of multidrug resistance has remained high since 1993 (50% in 2004) and there was a dramatic increase in nalidixic acid resistance between 1993 (4%) and 2005 (97%). In a cross-sectional sample of 381 serovar Typhi strains from 8 Asian countries, Bangladesh, China, India, Indonesia, Laos, Nepal, Pakistan, and central Vietnam, collected in 2002 to 2004, various rates of multidrug resistance (16 to 37%) and nalidixic acid resistance (5 to 51%) were found. The eight Asian countries involved in this study are home to approximately 80% of the world's typhoid fever cases. These results document the scale of drug resistance across Asia. The Ser83-->Phe substitution in GyrA was the predominant alteration in serovar Typhi strains from Vietnam (117/127 isolates; 92.1%). No mutations in gyrB, parC, or parE were detected in 55 of these strains. In vitro time-kill experiments showed a reduction in the efficacy of ofloxacin against strains harboring a single-amino-acid substitution at codon 83 or 87 of GyrA; this effect was more marked against a strain with a double substitution. The 8-methoxy fluoroquinolone gatifloxacin showed rapid killing of serovar Typhi harboring both the single- and double-amino-acid substitutions.