A one health framework for the evaluation of rabies control programmes: a case study from Colombo City, Sri Lanka

Abstract

Background: One Health addresses complex challenges to promote the health of all species and the environment by integrating relevant sciences at systems level. Its application to zoonotic diseases is recommended, but few coherent frameworks exist that combine approaches from multiple disciplines. Rabies requires an interdisciplinary approach for effective and efficient management.

Methodology/principal findings: A framework is proposed to assess the value of rabies interventions holistically. The economic assessment compares additional monetary and non-monetary costs and benefits of an intervention taking into account epidemiological, animal welfare, societal impact and cost data. It is complemented by an ethical assessment. The framework is applied to Colombo City, Sri Lanka, where modified dog rabies intervention measures were implemented in 2007. The two options included for analysis were the control measures in place until 2006 ("baseline scenario") and the new comprehensive intervention measures ("intervention") for a four-year duration. Differences in control cost; monetary human health costs after exposure; Disability-Adjusted Life Years (DALYs) lost due to human rabies deaths and the psychological burden following a bite; negative impact on animal welfare; epidemiological indicators; social acceptance of dogs; and ethical considerations were estimated using a mixed method approach including primary and secondary data. Over the four years analysed, the intervention cost US $1.03 million more than the baseline scenario in 2011 prices (adjusted for inflation) and caused a reduction in dog rabies cases; 738 DALYs averted; an increase in acceptability among non-dog owners; a perception of positive changes in society including a decrease in the number of roaming dogs; and a net reduction in the impact on animal welfare from intermediate-high to low-intermediate.

Conclusions: The findings illustrate the multiple outcomes relevant to stakeholders and allow greater understanding of the value of the implemented rabies control measures, thereby providing a solid foundation for informed decision-making and sustainable control.

Figure 1. Overview of a conceptual integrated framework for the assessment of rabies control strategies.

Figure 2. Influence of input variables on monetary health costs.

Sensitivity analysis results where distinct input variables were varied by ±15% and the impact measured on the difference in monetary human health costs (in 2011 US $) between the intervention and the baseline scenario (BS). ◊ = base value = US $ -215,064.

Figure 3. Influence of input variables on non-monetary health costs.

Sensitivity analysis results where distinct input variables were varied by ±15% and the impact measured on the Disability Adjusted Life Years (DALYs) averted. ◊ = base value = 738 DALYs averted.

Figure 4. Dog related problems listed in Colombo City, Sri Lanka.

The number of focus groups (1 to 9) that listed specific dog related problems perceived for the years 2006 (blue line) and 2011 (red line) in Colombo City, Sri Lanka.