How much does it cost to prevent and control visceral leishmaniasis in Brazil? Comparing different measures in dogs

PLoS One. 2020 Jul 21;15(7):e0236127. doi: 10.1371/journal.pone.0236127. eCollection 2020.

Abstract

Visceral leishmaniasis (VL) is an important zoonosis in Brazil. Dogs are considered the main domestic reservoirs of the disease in the country; hence, control measures are focused on these reservoirs. Despite efforts to prevent and control VL, important reductions in disease prevalence and incidence have not been identified, stimulating the development and application of new strategies. The choice and implementation of new control strategies can benefit from the application of mathematical models that allow the simulation of different strategies in different scenarios. Selecting the best strategy to be implemented is also supported by cost-effectiveness studies. Here we used the results of a mathematical model in which scenarios, including isolated use of the vaccine and insecticide-impregnated collar (IIC), both at different coverage rates, were simulated to conduct a cost-effectiveness study. The costs were calculated for each scenario considering a simulation period of four years. Collar application in both infected and non-infected animals was the most cost-effective strategy. For example, to reduce the prevalence in humans and dogs by approximately 70%, the costs ranged from $250,000 and $550,000 for the IICs and vaccination, respectively. Even in the scenario with 40% loss/replacement of IICs, this measure was more advantageous in terms of cost-effectiveness than vaccination. If the vaccine were applied with culling of seropositive tested dogs, then the measure became more effective with a reduced cost compared with the vaccine alone. The use of the three first consecutive vaccine doses had the greatest impact on the cost of the vaccination strategy. The advantage of using IICs is that there is no need for a prior diagnosis, unlike vaccination, reducing costs and facilitating implementation. The present study aims to contribute to strategies to reduce hosts infected with VL by reducing public expenditure.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brazil / epidemiology
  • Dog Diseases / economics*
  • Dog Diseases / parasitology
  • Dog Diseases / prevention & control*
  • Dog Diseases / transmission
  • Dogs
  • Leishmania donovani / drug effects*
  • Leishmania donovani / isolation & purification
  • Leishmaniasis, Visceral / economics*
  • Leishmaniasis, Visceral / epidemiology
  • Leishmaniasis, Visceral / prevention & control*
  • Leishmaniasis, Visceral / veterinary
  • Prevalence
  • Vaccination / economics*
  • Vaccination / veterinary*

Grants and funding

Between 2010 and 2014 the authors had two funders for the execution of a doctoral project, that was the basis for this study. One of them, received from “Brazilian Council for Scientific and Technological Development - CNPq”, was designed for the student salary for study design, data collection and analysis. The other was from “São Paulo Research Foundation (FAPESP)” (grant number: 2012/01442-4), for data collection in the field. The product of this research was published in PLOS ONE, being one of the 10% most cited articles in 2019. However, these both funders had no role in decision to analysis, publish, or preparation of the manuscript of the present study. The publication was financed by Brazilian Council for Scientific and Technological Development - CNPq (grant number: 307482/2018-9).