Extended-spectrum beta-lactamases (ESBLs) were present in high proportions of Escherichia coli (25% [9 of 36]) and Klebsiella pneumoniae isolates (17% [9 of 52]) causing pediatric septicemia at a tertiary hospital in Tanzania. Patients with septicemia due to ESBL-producing organisms had a significantly higher fatality rate than those with non-ESBL isolates (71% versus 39%, P ؍ 0.039). This is the first report of the CTX-M-15 genotype of ESBLs on the African continent and the first observation of SHV-12 genotype in an isolate of Salmonella enterica serotype Newport. Resistance to beta-lactam antibiotics was demonstrated inEscherichia coli even before penicillin was released for clinical use. In the 1960s, the first plasmid-transferable beta-lactamase was discovered and named TEM-1 after Temoniera, the Greek girl who harbored the E. coli isolate from which the enzyme was obtained. Since the 1980s, a large number of plasmid-transferable extended-spectrum beta-lactamases (ESBLs) capable of inactivating extended-spectrum cephalosporins has been discovered (6). Most of the ESBLs are derived from TEM-1 and SHV-1 (sulfhydryl variable) by mutations. ESBLs have spread widely and have become a major cause of nosocomial infections associated with high mortality rates, particularly in serious infections such as septicemia (12). In Africa, ESBLs have been reported in Egypt (19), Tunisia (4, 5), Morocco (2), Senegal (18,20), Nigeria (1), South Africa (9), and Kenya (11) but not previously from Tanzania. In the present study, we investigated the prevalence and clinical implications of ESBL production in E. coli, Klebsiella pneumoniae, and salmonellae causing septicemia in infants and children admitted to a tertiary teaching hospital in Tanzania. MATERIALS AND METHODSFrom August 2001 to August 2002, blood cultures were obtained from 1,798 children aged 0 to 7 years with a fever of Ն38°C or other signs of severe infections admitted to the Pediatric Department at Muhimbili National Hospital, a tertiary referral hospital in Dar es Salaam, Tanzania. We included in the present study 113 children who had growth in blood culture of one or more isolates of E. coli, Klebsiella spp., or salmonellae.Blood specimens (1 ml from neonates and 5 ml from older children) were inoculated in BACTEC Myco/F lytic blood culturing vials (Becton Dickinson, Franklin Lakes, N.J). Positive blood cultures were subcultured on Columbia II agar base (Oxoid Ltd, Basingstoke, United Kingdom) with 5% human blood, chocolate agar, and MacConkey agar (Difco/BD Diagnostic Systems, Sparks, Mich.). The isolates were identified according to established procedures (7).Klebsiella spp. were identified with the API 20E system (bioMérieux SA, Marcy l'Etoile, France). Susceptibilities against antimicrobial agents were tested by the disk diffusion method according to NCCLS guidelines (15). Isolates of E. coli, Klebsiella spp., and salmonellae with reduced susceptibilities to cefotaxime (zone diameter of Յ27 mm) and/or ceftazidime (zone diameter of Յ22 mm) according to guidel...
ABSTRACT. Objective. Evidence from animal experiments and observational studies in humans suggests that vitamin A plays a fundamental role in physical growth. However, results from vitamin A supplementation trials in children are inconsistent; whereas some did not find an overall effect on growth, others found benefits only among specific groups, including children with low concentrations of serum retinol or short duration of breastfeeding. The apparent lack of an overall effect of vitamin A on growth could be attributed to context-specific distribution of conditions that affect both growth and the response to supplementation, eg, baseline vitamin A status, deficiency of other nutrients (fat, zinc), and the presence of infectious diseases. Human immunodeficiency virus (HIV) infection, malaria, and diarrheal disease adversely affect growth and are associated with increased prevalence of vitamin A deficiency. We hypothesize that vitamin A supplementation could ameliorate the adverse effect of these infections on child growth.Methods. We conducted a randomized, clinical trial among 687 Tanzanian children who were 6 to 60 months of age and admitted to the hospital with pneumonia. Children were assigned to oral doses of 200 000 IU vitamin A (half that dose if <12 months) or placebo on the day of admission, a second dose on the following day, and third and fourth doses at 4 and 8 months after discharge from the hospital, respectively. Anthropometric measurements were obtained at baseline and at monthly visits to the study clinics during 12 months after the initial hospitalization. Surveillance on the incidence and severity of diarrhea and respiratory infections was conducted during biweekly visits, alternately at a study clinic and the child's home, using a pictorial diary that the mothers were trained to use. A blood specimen was drawn at baseline for determination of HIV status, malaria infection, and hemoglobin levels. We used mixed effects models to compare estimated total weight and height increases after 1 year of follow-up between treatment arms, overall and within levels of HIV status, malaria, and other possible baseline effect modifiers. We also assessed the potential modulating effect of vitamin A on the risk of stunting (height-for-age <؊2 standard deviations of the gender-specific National Center for Health Statistics median reference) attributable to diarrheal and respiratory infections during follow-up, in the subset of children who were not stunted at baseline. A similar approach was followed for wasting (weight-forheight <؊2 standard deviations of the reference median). Cox regression models were used to estimate relative risks and 95% confidence intervals (CI), treating episodes of infection as time-dependent covariates.Results. A total of 554 children had at least 2 follow-up measurements of height or weight and constituted the study base. Baseline characteristics did not differ significantly by treatment arm. Seventy-three percent of the children were <2 years of age, and 37% were <12 months; 31% w...
Vitamin A deficiency, which is common among children in many developing countries, is particularly severe among HIV-infected children. Our findings indicate that vitamin A supplements, a low cost intervention, reduce mortality of HIV-infected children.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.