Trends in antimicrobial resistance of bacterial pathogens in Harare, Zimbabwe, 2012–2017: a secondary dataset analysis

BACKGROUND: Antimicrobial resistance is one of the most serious public health threats of the twenty-first century. The implementation of AMR surveillance in Zimbabwe is limited. However, data from a private laboratory in Harare revealed increasing resistance rates to common antibiotics like ampicillin (i.e., from 73.9% in 2011 to 74.6% in 2015). The increasing resistance rates indicate that Zimbabwe is affected by AMR. This study was done to determine the magnitude of AMR in Harare and determine the trends of AMR to first-line and to last-resort antibiotics and make recommendations to mitigate the problem. METHODS: A retrospective record review of data collected from the microbiology department at a private laboratory between January 2012 and December 2017 was done. The outcome of interest was the antibiotic susceptibility of bacterial isolates. Microsoft Excel 2016 was used to plot trends from 2012 to 2017 and Epi Info™7 was used for statistical analysis. RESULTS: A total of 23,432 isolates, of 12 medically important bacteria were analysed. Forty-three percent of the isolates were from urines, 36.7% were from pus swabs and 7% were from blood. The most common pathogen was Escherichia coli (43.2%), followed by Staphylococcus aureus (15.8%) and the least common was Neisseria gonorrhoea (0.2%). Resistance was highest to ampicillin followed by penicillin, both ranging between 70 and 100% over the six years. Statistically significant increases in resistance to commonly used antibiotics were observed in amoxicillin-resistant E. coli and Streptococcus pneumonia and third generation cephalosporin-resistant E. coli. There was an increase in resistance to last-line antibiotics i.e., fluoroquinolone-resistant Salmonella spp. and carbapenem-resistant Pseudomonas aeruginosa and Acinetobacter baumannii. However, methicillin-resistant S. aureus showed a decreasing trend. CONCLUSIONS: There is a high burden of drug resistance to common antibiotics in Harare and an emergence of resistance to last-line antibiotics.