Estimating the Fitness Cost and Benefit of Cefixime Resistance in Neisseria Gonorrhoeae
2017
Gonorrhoea is one of the most common bacterial sexually transmitted infections in England, and more than half of annual infections occur in men who have sex with men (MSM). As the bacterium has developed resistance to each first-line antibiotic in turn, an improved understanding is needed of fitness benefits and costs of antibiotic resistance to inform control policy and planning.
The authors developed a stochastic compartmental model representing the natural history and transmission of cefixime-sensitive and cefixime-resistant strains of Neisseria gonorrhoeae in MSM in England, which was applied to data on diagnoses and prescriptions between 2008 and 2015. The model includes a fitness benefit of resistance, to explain why cefixime resistance increased when cefixime was widely used up until 2010. The model also includes a fitness cost of resistance, to explain why cefixime resistance decreased from 2010. Having inferred the fitness cost and benefit of cefixime resistance, they were able to predict what would happen if cefixime was reintroduced and found that it could be used to treat up to 25% of gonorrhoea cases without risk.
The results have important implications for antibiotic stewardship and public health policies and, in particular, suggest that a previously abandoned antibiotic could be used again to treat a minority of gonorrhoea cases without raising resistance levels.
Estimating the Fitness Cost and Benefit of Cefixime Resistance in Neisseria Gonorrhoeae
Source:
Whittles LK, White PJ, Didelot X. Estimating the Fitness Cost and Benefit of Cefixime Resistance in Neisseria Gonorrhoeae to Inform Prescription Policy: A Modelling Study. PLOS Medicine 2017; 14 (10): e1002416. https://doi.org/10.1371/journal.pmed.1002416