Pests and diseases: not just a national concern!

Just as nature abhors a vacuum so pests and diseases, if left unchecked, will spread actively and passively throughout any suitable ecosystems available to them, regardless of national boundaries. The well-being of large human populations is then put at risk. The containment of noxious organisms is therefore an international imperative, but this must be achieved with minimum hindrance to trade and to agricultural diversification and development.

Plague-type pests such as the desert locust (Schistocerca gregaria) can occur in swarms of up to 40,000 million individuals together weighing 80,000 tons and devouring their own weight of green vegetation daily. They regularly invade 11 million square miles of land in some 66 countries occupied by 20% of the world's population and, for them, international strategic control is the only answer. The end of the last 25 year plague in 1963 was hastened, if not occasioned, by such control based on sound up-to-date field intelligence on the breeding, concentration and movement of the pest, and accurate predictions of its spread derived from meteorological information. Likewise with the African arymworm (Spodoptera exempta), accurate forecasting of concentrations and their early control has prevented the spread of epidemics from their country of origin to susceptible neighbouring territories. Effective intelligence, early warning and information exchange systems are similarly the foundations of successful containment of contagious livestock diseases such as rinderpest, which in the past has killed-off most domestic ruminants and pigs in Africa from Eritrea to the Cape of Good Hope.

It is the lack of such shared intelligence and early-warning systems (i.e. the lack of notification of pest and disease incidence and international information exchange systems) that has contributed to many of the exotic-pest calamities of the past. And it is the continuing inward-looking and parochial approach of many individual countries, based on national rather than international perspectives, that is the weak link in the global movement for the safe transfer and exchange of plant and animal material.

Had Tanzania, Ghana, Togo and other importing countries been advised in advance of the threat of the larger grain borer (LOB) (Prostephanus truncatus) in maize shipments from the Americas the introduction of this pest which at one time was estimated to have cost Tanzania some $87 million per annum, could have been prevented. Would the cassava mealy bug (Phenococcus manihoti) have spread so widely throughout Africa if its introduction had been promptly reported by the country concerned? And would its successful control by Apoanagyrus lopezi been achieved without pest-intelligence and collaboration of international dimensions? The American screw worm (Cochliomyia hominivorax) would have spread and devastated domestic stock throughout Africa, had not its arrival in Libya been promptly notified and an internationally-supported eradication campaign instantly initiated.

Effective quarantine, in the form of prohibition of movement of noxious organisms within and between countries, is vital in the world-wide aspiration of facilitating the safe movement of plant and animal material The few examples given above illustrate both failures and successes of quarantine containment and exclusion exercises. The lesson emerging from them is the need for a truly international approach based on prompt sharing of pest and disease intelligence, concerted international action, and harmonization of legislation together with its enforcement, through the adoption of inspection and treatment techniques and certification procedures and standards.

With the onus for phytosanitary standards shifting world-wide from the importing to the exporting countries, the need for harmonization and transparency is urgent. The mechanism to achieve this exists in the form of the International Plant Protection Convention (IPPC) under FAO to which all countries must, for their own benefit, be signatories and adherents (See box). Its aim is to make quarantine effective without being an impediment to trade and development - an aspiration which surely is shared and welcomed by all.

The world is shrinking, and the diversification of trade and the expansion of trading links has brought an international dimension to the meaning of "neighbouring countries". To continue to "love thy neighbour" when that neighbour, through neglect, is the cause of economically crippling pest and disease situations in one's homeland, demands exceptional compassion - a compassion easily clouded by calls for compensation!

The International Plant Protection Convention (IPPC)

The IPPC, which was first approved by the sixth FAO Conference in 1951, came into force in 1952 and has been revised periodically to keep abreast with world needs. Its aim is to secure common and effective action to prevent the spread of plant pests across borders and to permit measures for their control. It provides for the establishment of national plant protection services and the issuance of phytosanitary certificates. IPPC also sets requirements for imports and international cooperation and provides a system for settlement of disputes. Under the IPPC governments agree to cooperate in establishing Regional Plant Protection Organizations (RRPOs), to function as coordinating bodies for the conformation of legislation and its enforcement, inspection and treatment techniques and standards and certification. RPPOs exist in Asia; Africa; North, Central and South America; the Caribbean; Europe and the South Pacific. Some 100 countries are signatories to the IPPC leaving some 60 or more yet to sign the Convention.

The IPPC has been given additional technical responsibility for developing recommendations, guidelines and standards for the General Agreement on Tariffs and Trade (GATT), the members of which recognize that unjustified quarantine restrictions could be used as non-tariff barriers to trade. IPPC's response has been to seek agreement of the principles of quarantine and pest risk analysis, together with other aspects listed above. 'Transparency' ensuring that import restrictions are clearly 'visible' to trading partners and that the mechanism for determining restrictions is Pest Risk Analysis · is a major concern. Countries which ratify the Convention and accept its guidelines, recommendations and standards are not challengeable under the rules of GATT.