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Livestock Production Losses Attributable to Brucellosis in Northern and Central Tanzania: Application of an Epidemiological-economic Modelling Framework

Abstract

Livestock brucellosis is an endemic disease in many low-resource settings. Despite its widespread distribution, little is known about the scale of economic impacts caused by the disease. This study aimed to develop an integrated epidemiological-economic modelling framework to estimate production losses attributable to livestock brucellosis, using Tanzania as a case study. Data on livestock production and prevalence of exposure to Brucella spp. were obtained from surveys conducted in northern and central Tanzania between 2013 and 2019. A clustering algorithm was applied to classify households into pastoral and non-pastoral production systems. A Bayesian latent-class analysis model was applied to derive livestock brucellosis prevalence estimates. A herd-growth model was used to estimate production losses attributable to brucellosis. A total of 1,541 households (384 classified as pastoral and 1,157 as non-pastoral) contributed data on livestock production or prevalence of exposure to Brucella spp. The median (95% uncertainty interval, UI) individual-level brucellosis prevalence in cattle, sheep, and goats was 5.1% (3.4-6.9), 1.3% (0.1-3.0), and 2.5% (0.3-4.8) in the pastoral system, and 0.7% (0.1-1.6), 1.6% (0.2-3.8), and 2.5% (0.3-4.9) in the non-pastoral system, respectively. The median (95% UI) annual losses attributable to brucellosis in cattle, sheep, and goats, per infected animal, were 74.4 (26.2-211.7), 9.7 (3.4-23.1) and 10.6 (3.7-25.0) international dollars (int. $) in the pastoral system, and 62.3 (16.8-228.6), 6.3 (1.8-17.1) and 7.0 (2.2-17.9) int. $ in the non-pastoral system, respectively. Household-level losses were equivalent to 4.4% (2.1-8.8) and 0.6% (0.2-1.6) of the median (95% UI) livestock-derived income in the pastoral and non-pastoral systems, respectively. This study did not capture the system-wide impacts of brucellosis, including on human health. The estimated losses are only a part of the full societal economic impact of the disease. These results can be used to inform cost-benefit analyses of potential interventions and guide policy development for brucellosis control.

References
1.
Cleaveland S, Sharp J, Abela-Ridder B, Allan K, Buza J, Crump J . One Health contributions towards more effective and equitable approaches to health in low- and middle-income countries. Philos Trans R Soc Lond B Biol Sci. 2017; 372(1725). PMC: 5468693. DOI: 10.1098/rstb.2016.0168. View

2.
Shirima G, Masola S, Malangu O, Schumaker B . Outbreak investigation and control case report of brucellosis: experience from livestock research centre, Mpwapwa, Tanzania. Onderstepoort J Vet Res. 2015; 81(1). DOI: 10.4102/ojvr.v81i1.818. View

3.
Moriyon I, Blasco J, Letesson J, De Massis F, Moreno E . Brucellosis and One Health: Inherited and Future Challenges. Microorganisms. 2023; 11(8). PMC: 10459711. DOI: 10.3390/microorganisms11082070. View

4.
Varijakshapanicker P, McKune S, Miller L, Hendrickx S, Balehegn M, Dahl G . Sustainable livestock systems to improve human health, nutrition, and economic status. Anim Front. 2020; 9(4):39-50. PMC: 6951866. DOI: 10.1093/af/vfz041. View

5.
Bodenham R, Mazeri S, Cleaveland S, Crump J, Fasina F, de Glanville W . Latent class evaluation of the performance of serological tests for exposure to Brucella spp. in cattle, sheep, and goats in Tanzania. PLoS Negl Trop Dis. 2021; 15(8):e0009630. PMC: 8384210. DOI: 10.1371/journal.pntd.0009630. View