Proportion of extended-spectrum β-lactamase (ESBL)-producing isolates among Enterobacteriaceae in Africa: evaluation of the evidence--systematic review.
Extended-spectrum β-lactamases (ESBLs) have become widespread around the world. We sought to evaluate the proportion of ESBL-producing isolates among Enterobacteriaceae in Africa. A systematic search in the PubMed and Scopus databases was performed in order to identify studies providing the proportion of ESBL-producing isolates among patients either infected or colonized with Enterobacteriaceae. In an effort to incorporate contemporary data, only studies published from 2005 onwards and, among them, only those including isolates that were recovered from 2000 onwards were eligible. Twenty-six studies (409 ,215 isolates) from 13 African countries met the inclusion criteria. The proportion of ESBL-producing isolates among 13 studies reporting on isolates from a urinary source varied from 1.5% to 22.8%. Four other studies evaluated various clinical samples from different hospitals, showing that the proportion varied from 12.8% to 21.1%. Last, the proportions were 0.7%, 14%, 15.2% and 75.8%, respectively, in four studies evaluating patients with bloodstream infection. In particular, the proportion was 0.7% in a study from Malawi where ceftriaxone was the only available cephalosporin and was 75.8% in a study from Egypt that included only patients from intensive care units. In total, the proportion of ESBL-producing isolates was <15% in 16 out of 26 studies. Data originating from a small number of African countries suggest that the proportion of ESBL-producing isolates among Enterobacteriaceae may not be high in Africa, but is certainly not negligible. Further studies are needed from countries where no or limited relevant data are available.