An Expost Economic Impact Assessment of the Intervention against Highly Pathogenic Avian Influenza in Nigeria

The risk of spread of HPAI in Nigeria was derived by using a compartmental model to outline endemic and burn-out scenarios. Two paths, low and high mortality risks, were associated to each of the scenarios. The estimated risk parameters were then used to stochastically simulate the trajectory of the disease; without intervention and with an intervention. The intervention costs the country US$ 41 million obtained through a World Bank IDA loan of US$ 50million yearly disbursed over the 2006-2010 period. The key output variables (net social welfare gain – with incremental net benefits as proxy, disease cost, and benefit cost ratio) were estimated for each randomly drawn risk parameter. On average, the results show that such an intervention would make economic sense under the endemic scenario with high mortality. The discounted costs (12% discount rate) of the disease without intervention would have amounted to US$ 145 million in total over the 2006-2010 period. The model indicates that the intervention could possibly have generated cost savings amounting to US$ 63.7 million, incremental net benefit of US$22.2 million, and a benefit cost ratio at 1.75 over the five-year period considered.