Cost-Benefit Analysis of a Mass Vaccination Strategy to Control Brucellosis in Sheep and Goats in Northern Iraq

Abstract

Brucellosis is a major economic and production-limiting disease for livestock owners and the community in Iraq. A cost-benefit analysis was conducted to evaluate the impact of an expanded annual mass vaccination programme of sheep and goats that involves all female and male sheep and goats over the age of 3 months with Rev. 1 vaccine. The proposed expanded vaccination programme was compared to the current annual vaccination program, which involved only vaccinating female sheep and goats between the ages of 3 and 6 months of age with Rev. 1. The cost-benefit analysis model was developed utilizing data collected in Dohuk Governorate, northern Iraq. The seroprevalence in small ruminants (using Rose Bengal test and ELISA in series) was predicted to decrease from 9.22% to 0.73% after 20 years of implementing the proposed annual mass vaccination program. The net present value of the mass vaccination program was estimated to be US$ 10,564,828 (95% Confidence Interval (CI): -16,203,454 to 37,049,245), the benefit-cost ratio was estimated to be 4.25 (95% CI: -2.71 to 11.22), and the internal rate of return was 91.38% (95% CI:11.71 to 190.62%). The proposed vaccination strategy was predicted to decrease the overall financial loss caused by brucellosis from 1.75 to 0.55 US$ per adult female animal. The results of this economic analysis highlight the benefit of implementing an annual mass vaccination program of small ruminants with Rev. 1 vaccine to reduce the prevalence of brucellosis in northern Iraq.

Keywords: Iraq; brucellosis; economic analysis; small ruminants; vaccination.

Figure 1

Estimated decline in the prevalence of Brucella (a) when implementing a mass vaccination programme over twenty years (horizontal axis). The figure depicts the avoided pregnancy loss (b), avoided milk loss (c), and the predicted total loss avoided (d) over twenty years of application of the proposed mass vaccination.

Figure 2

Regression coefficients of the sensitivity analysis for net present value (NPV) of the mass vaccination control programme.