The Estimated Medical Costs Averted By Maintaining the Prevalence of Ceftriaxone-Resistant Neisseria Gonorrhoeae below 2% in Accordance with the Targets of the National Strategy for Combating Antibiotic Resistant Bacteria

Background: One of the targets of the National Strategy for Combating Antibiotic Resistant Bacteria is to maintain the prevalence of ceftriaxone-resistant Neisseria gonorrhoeae at less than 2%. Gonococcal resistance can potentially increase gonorrhea incidence rates through factors such as increased duration of infection. We estimated the potential increase in the economic burden of gonorrhea in a scenario of emerging resistance.

Methods: We estimated gonorrhea incidence over a ten year period (year 1 to year 10) using a simple model in which the gonorrhea rate in a given year was a function of several factors, including the percentage of gonorrhea cases resistant to treatment in the previous year.  Model assumptions were informed by a published analysis of historical gonorrhea surveillance data and antimicrobial resistance data. We assumed 820,000 cases of gonorrhea annually in the absence of resistance. In the first scenario, we assumed the prevalence of resistance would remain at 2% for years 1-10.  In the second scenario, we assumed the prevalence of resistance would increase linearly from 2% in year 1 to 15% in year 6, as observed during the emergence of fluoroquinolone-resistant N. gonorrhoeae, and remain at 15% through year 10.  We included the direct lifetime medical costs (2014 $US) of gonorrhea and gonorrhea-attributable HIV cases, based on published cost and probability estimates.

Results:  Over 10 years and when compared to maintaining prevalence of resistance at 2%, emerging resistance would contribute to an estimated 1,157,000 additional gonorrhea cases (costing $257 million) and 607 additional gonorrhea-attributable HIV cases (costing $209 million), for a total cost of $466 million without discounting and $392 million when future costs are discounted at 3% annually.  

Conclusions: Preventing the emergence of ceftriaxone-resistant N. gonorrhoeae in accordance with the National Strategy for Combating Antibiotic Resistant Bacteria targets can potentially yield substantial health and economic benefits.