RESUMO
Gonorrhoea is one of the most common sexually transmitted infections. The control of gonorrhoea is extremely challenging because of the repeated development of resistance to the antibiotics used for its treatment. We explored different strategies to control the spread of antimicrobial resistance and prevent increases in gonorrhoea prevalence. We used a mathematical model that describes gonorrhoea transmission among men who have sex with men and distinguishes gonorrhoea strains sensitive or resistant to three antibiotics. We investigated the impact of combination therapy, switching first-line antibiotics according to resistance thresholds, and other control efforts (reduced sexual risk behaviour, increased treatment rate). Combination therapy can delay the spread of resistance better than using the 5% resistance threshold. Increased treatment rates, expected to enhance gonorrhoea control, may reduce gonorrhoea prevalence only in the short term, but could lead to more resistance and higher prevalence in the long term. Re-treatment of resistant cases with alternative antibiotics can substantially delay the spread of resistance. In conclusion, combination therapy and re-treatment of resistant cases with alternative antibiotics could be the most effective strategies to prevent increases in gonorrhoea prevalence due to antimicrobial resistance.
Assuntos
Antibacterianos/uso terapêutico , Farmacorresistência Bacteriana , Gonorreia/prevenção & controle , Neisseria gonorrhoeae , Saúde Pública , Controle de Doenças Transmissíveis , Substituição de Medicamentos , Quimioterapia Combinada , Gonorreia/tratamento farmacológico , Gonorreia/transmissão , Homossexualidade Masculina , Humanos , Masculino , Modelos Teóricos , Assunção de RiscosRESUMO
The impact of hepatitis B vaccination in men having sex with men in Amsterdam has been marginal until now, possibly because of increases in sexual risk behaviour counterbalancing the effect of vaccination. A mathematical model is used to describe the hepatitis B epidemic. The model shows that, with the current vaccination coverage, the decrease in incidence is small in the beginning. However, the number of infections prevented per vaccine administered rises over time. Nevertheless, increased risk behaviour reduces the benefit of vaccination. Targeting high-risk men is more successful in reducing and containing the epidemic than targeting low-risk men. In conclusion, the vaccination campaign is effective and should be intensified. High-risk men should be targeted for vaccination and for risk reduction.
