When Does Overuse of Antibiotics Become a Tragedy of the Commons?
Figure 3
Assessment of the effect of over-treatment of mild infection on the treatment of mild infections.
It was assumed that severely infected individuals do not transmit, and that drug resistance does not develop during treatment of severe infections. The mean time to treatment is set at 5 (arbitrary units) for mild infection, and 1/3 units for severe infection. All other expected waiting times (recovery, progression) are equal to 1. The reproduction number for the drug-sensitive organism is 1.5. See Text for full details of Model 2. Under these assumptions, the drug-resistant organism competitively excludes the drug-sensitive organism whenever the relative transmissibility exceeds 10/11 (91%) (grey area, labeled “No sensitive strain”). The parameters are ,
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. The horizontal axis corresponds to
and the vertical axis to
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