Development and validation of SR-DISVAXFIC: A mobile phone application for estimating the herd-level financial impact of small ruminant diseases and the potential benefits of vaccination in the field

Small ruminants are important to livelihoods in rural Nigeria and kept under sedentary and nomadic (transhumance) husbandry systems. Diseases such as sheep pox (SPP) and goat pox (GTP) result in significant financial losses and control is by vaccination. We developed and validated a mobile phone application (small ruminant’s disease vaccination and financial impact calculator: SR-DISVAXFIC) to estimate herd-level costs and vaccination benefits for small ruminant diseases in the field with real-time estimations. Previously developed production and economic models were adapted for application development and two validation stages undertaken: (i) SR-DISVAXFIC was presented and tested at a stakeholder meeting and (ii) veterinarians used SR-DISVAXFIC to collect data from sedentary and nomadic farmers who had experienced SPP and GTP outbreaks across five Northern Nigerian states (n = 291).

Median disease costs estimated were £ 301 (IQR: £163–516) for sedentary and £ 393 (IQR: £269–1029) for nomadic herds. Vaccination was financially beneficial, regardless of the percentage of government subsidisation; with a median herd-level benefit and median benefit-cost ratio of £ 272 (IQR: 149–475) and 7.00 (IQR: 5.04–16.74) for sedentary and £ 345 (IQR: £238–831) and 4.28 (IQR: 3.55–8.87) for nomadic herds. Differences between values estimated by SR-DISVAXFIC and previous stochastic modelling demonstrate the importance of gathering input parameters in the field to provide estimates. Majority (91.7 %) of participating farmers said SR-DISVAXFIC was useful to understand the financial impact of disease, and veterinarians found the application beneficial in explaining abstract concepts. SR-DISVAXFIC can be used to monitor trends in epidemiological parameters, costs, and financial impact of any small ruminant diseases.