EVALUATING TREATMENT PROTOCOLS TO PREVENT ANTIBIOTIC-RESISTANCE

The spread of bacteria resistant to antimicrobial agents calls for pop ulation-wide treatment strategies to delay or reverse the trend toward antibiotic resistance. Here we propose new criteria for the evaluatio n of the population-wide effects of treatment protocols for directly t ransmitted bacterial infections and discuss different usage patterns f or single and multiple antibiotic therapy, A mathematical model sugges ts that the long-term benefit of single drug treatment from introducti on of the antibiotic until a high frequency of resistance precludes it s use is almost independent of the pattern of antibiotic use. When mor e than one antibiotic is employed, sequential use of different antibio tics in the population (''cycling'') is always inferior to treatment s trategies where, at any given time, equal fractions of the population receive different antibiotics, However, treatment of all patients with a combination of antibiotics is in most cases the optimal treatment s trategy.