Antimicrobial resistance in Africa: a systematic review

Abstract

Background: Antimicrobial resistance (AMR) is widely acknowledged as a global problem, yet in many parts of the world its magnitude is still not well understood. This review, using a public health focused approach, aimed to understand and describe the current status of AMR in Africa in relation to common causes of infections and drugs recommended in WHO treatment guidelines.

Methods: PubMed, EMBASE and other relevant databases were searched for recent articles (2013-2016) in accordance with the PRISMA guidelines. Article retrieval and screening were done using a structured search string and strict inclusion/exclusion criteria. Median and interquartile ranges of percent resistance were calculated for each antibiotic-bacterium combination.

Results: AMR data was not available for 42.6% of the countries in the African continent. A total of 144 articles were included in the final analysis. 13 Gram negative and 5 Gram positive bacteria were tested against 37 different antibiotics. Penicillin resistance in Streptococcus pneumoniae was reported in 14/144studies (median resistance (MR): 26.7%). Further 18/53 (34.0%) of Haemophilus influenza isolates were resistant to amoxicillin. MR of Escherichia coli to amoxicillin, trimethoprim and gentamicin was 88.1%, 80.7% and 29.8% respectively. Ciprofloxacin resistance in Salmonella Typhi was rare. No documented ceftriaxone resistance in Neisseria gonorrhoeae was reported, while the MR for quinolone was 37.5%. Carbapenem resistance was common in Acinetobacter spp. and Pseudomonas aeruginosa but uncommon in Enterobacteriaceae.

Conclusion: Our review highlights three important findings. First, recent AMR data is not available for more than 40% of the countries. Second, the level of resistance to commonly prescribed antibiotics was significant. Third, the quality of microbiological data is of serious concern. Our findings underline that to conserve our current arsenal of antibiotics it is imperative to address the gaps in AMR diagnostic standardization and reporting and use available information to optimize treatment guidelines.

Keywords: Africa; Antimicrobial resistance; Bacteria; Systematic review.

Fig. 1

PRISMA Diagram of the article selection procedure for articles published between January 2013 and January 2016.The review has been registered to the PROSPERO database of systematic reviews on March 1, 2016 (http://www.crd.york.ac.uk/PROSPERO/myprospero.php) with ID CRD42016035923

Fig. 2

Geographical distribution and number of selected studies between January 2013 and January 2016 in the different African countries. Countries were grouped based on the United Nations Statistics Division classification into Eastern Africa, Southern Africa, Central Africa, Northern Africa and Western Africa

Fig. 3

Resistance of selected pathogens to commonly prescribed antibiotics in different regions of Africa. The boxplots in the figure represent the median and interquartile range of resistance reported if at least three studies reported on the combination. Resistance to amoxicillin-clavulanic acid (AMX-CLA), ampicillin, amoxicillin, penicillin, oxacillin, trimethoprim-sulfamethoxazole (TMP-SXT), gentamicin, ceftriaxone, cefoxitin, ciprofloxacin, erythromycin, tetracycline, vancomycin and imipenem were plotted. Antibiotics with no data points in the specific regions are omitted from the plots.Resistance patterns reported using broth dilution minimum inhibitory concentration (MIC), E-test® or VITEK® were included if prevalence could be calculated and were combined with resistance data reported using disk diffusion as this was the main method used. Intermediate susceptible strains were categorized as resistant to simplify the analysis. [13]MR estimates were not calculated if only one or two studies reported on the specific bacterium-antibiotic combination. a: Resistance of Klebsiella spp. to commonly prescribed antibiotics in different regions of Africa. b: Resistance of S. pneumoniae to commonly prescribed antibiotics in different regions of Africa. c: Resistance of S. aureus to commonly prescribed antibiotics in different regions of Africa. d: Resistance of E. coli to commonly prescribed antibiotics in different regions of Africa