The Economic Impact of Eradicating Peste des Petits Ruminants:A Benefit-Cost Analysis

Peste des petits ruminants (PPR) is an important cause of mortality and production loss among sheep and goats in the developing world. Despite control efforts in a number of countries, it has continued to spread across Africa and Asia, placing an increasing burden on the livelihoods of livestock keepers and on veterinary resources in affected countries. Given the similarities between PPR and rinderpest, and the lessons learned from the successful global eradication of rinderpest, the eradication of PPR seems appealing, both eliminating an important disease and improving the livelihoods of the poor in developing countries. We conducted a benefit-cost analysis to examine the conomic returns from a proposed programme for the global eradication of PPR. Based on our knowledge and experience, we developed the eradication strategy and estimated its costs. The benefits of the programme were determined from (i) the averted mortality costs, based on an analysis of the literature, (ii) the downstream impact of reduced mortality using a social accounting matrix, and (iii) the avoided control costs based on current levels of vaccination. The results of the benefit-cost analysis suggest strong economic returns from PPR eradication. Based on a 15-year programme with total discounted costs of US$2.26 billion, we estimate discounted benefits of US$76.5 billion, yielding a net benefit of US$74.2 billion. This suggests a benefit cost ratio of 33.8, and an internal rate of return (IRR) of 199%. As PPR mortality rates are highly variable in different populations, we conducted a sensitivity analysis based on lower and higher mortality scenarios. All the scenarios examined indicate that investment in PPR eradication would be highly beneficial economically. Furthermore, removing one of the major constraints to small ruminant production would be of considerable benefit to many of the most vulnerable communities in Africa and Asia

Peste des Petits Ruminants

Heartwater (or cowdriosis) is a tick-borne disease caused by Ehrlichia ruminantium, an obligatory intracellular bacterium of the order Rickettsiales, transmitted by several ticks of the genus Amblyomma. The organism is genetically highly variable which prevented until now the development of efficient vaccines. The disease is enzootic in sub-Sahelian Africa and in some Caribbean islands. It affects domestic and wild ruminants, the susceptibility to cowdriosis varying greatly between breeds and species: African wildlife shows mainly asymptomatic infections; local cattle breeds are generally protected due to enzootic stability; and introduced cattle breeds and small ruminants, even in enzootic regions, are usually susceptible to heartwater and can suffer high mortality rates. Cowdriosis is characterized by a sudden and acute fever followed by nervous, respiratory, and gastrointestinal symptoms and by hydrothorax and hydropericardium during postmortem examination. In West Africa, the only vector is Amblyomma variegatum, present in areas where pluviometry is higher than 500 mm. Therefore, animals of a high proportion of the Sahelian region are usually not infested by the tick and not infected by the bacterium. They are thus susceptible when introduced in southern parts of the Sahel or in the subhumid neighboring areas of the West African countries, for example during transhumance. Tetracyclines are effective drugs to treat heartwater when administered before occurrence of the nervous symptoms. Various vaccines have been tested, and are still developed, but, up to now, none of them showed enough effectiveness against all the field strains of E. ruminantium to allow its marketing. Prevention is therefore mainly achieved by drastic vector control or, on the contrary, acquisition of enzootic stability following tick infestation combined with tetracycline treatment as soon as hyperthermia occurs