Programmatic goals and spatial epidemiology influence the merit of targeted versus of population-wide interventions for yaws eradication

Abstract

Infectious disease eradication programs often pursue spatially targeted interventions, but how well they perform might depend on the underlying spatial epidemiology and the specific goal of the program. We use a stochastic compartmental metapopulation model of yaws transmission to investigate how total targeted treatment (TTT) performs compared to mass drug administration (MDA) in different settings. While TTT can efficiently control the prevalence of active yaws disease, we consistently found that multiple rounds of TTT are required to match the impact of 1 round of MDA on the prevalence of latent yaws infection. When complete eradication of yaws is the goal, MDA can achieve the same result as TTT more quickly and probably at lower cost. We found that the performance of TTT is improved when there is little mixing between subpopulations and when there is spatial heterogeneity in transmissibility, but even in these settings, our model suggests that MDA will still outperform TTT. Significance Statement Yaws is a neglected tropical disease that causes skin lesions. Eradicating yaws is challenging because people can be infected but not show any signs or symptoms for years. Using simulations, we found that targeting antibiotics to people with active yaws and to their neighbors is a good way to combat active yaws, but treating entire populations is a better way to get rid of all infections, including the hidden ones. Also, targeted treatment works better in populations in which people do not move around much and in which how easily the disease is transmitted varies from place to place. Overall, a targeted treatment strategy uses fewer antibiotics but takes longer than mass treatment to achieve results.