A systematic review of economic assessments for brucellosis control interventions in livestock populations

Brucellosis in livestock is a disease of paramount importance to animal and human health authorities due to its socio-economic and public health consequences. Benefit cost analyses can help policymakers decide whether allocation of resources is economically beneficial to cover the costs of brucellosis control interventions in populations. One broad question of interest is: what are the consequences of acting, or failing to act, on policy options of selected intervention scenarios (e.g., vaccination, test-and-slaughter, vaccination combined with test-and-slaughter, versus a status-quo scenario). The objective of the systematic review reported here was to conduct a critical appraisal of published research reports of economic assessments of brucellosis control interventions in livestock populations. The systematic review followed standard guidelines using a Population, Intervention, Comparison, Outcome, and Context framework and Preferred Reporting Items for Systematic Review and Meta-Analysis. The review targeted research reports focused on brucellosis control interventions in livestock populations at the national or regional level. Economic outcomes of interest were benefit-cost ratio (BCR), net present value, internal rate of return, or payback period. Eleven studies conducted in Brazil, China, India, Iraq, Mexico, Mongolia, Spain, Turkey, or the USA met the inclusion criteria and were included. The baseline prevalence of brucellosis in selected study populations ranged from 1.4% in cattle in Turkey to 20% in goats in Mexico. In six studies, selected intervention scenarios of vaccination alone produced BCRs that ranged from 3.2 in yaks in China or in cattle, sheep and goats in Mongolia, to 21.3 in cattle and/or buffalo in India. In three studies, interventions of test-and-slaughter produced BCRs that ranged from - 1.2 in goats in Mexico to 0.6 in cattle in Spain. In four studies, vaccination in combination with test-and-slaughter produced BCRs that ranged from 0.2 in yaks in China to 3.7 in cattle and buffalo in India. In seven studies, using sensitivity analysis, different input parameters (prevalence of brucellosis, meat price, cashmere price, vaccination coverage, test-and-slaughter coverage, milk price, vaccination protection, abortion cost, abortion rate, or price of lamb) had an impact on economic outcomes. Vaccination alone was cost-effective, but test-and-slaughter was not, for brucellosis control in selected livestock populations in focus countries. Vaccination in combination with test-and-slaughter produced profitable or nonprofitable economic outcomes. While most studies reported the cost and benefits of implementing brucellosis control interventions, only one study explained socio-economic consequences of economic outcomes, when acting, or failing to act, on selected interventions in livestock populations.