The final push against Rinderpest?
Experts from around the world met in Rome during May this year to discuss and determine the cost of strategies and techniques to finally and totally eradicate rinderpest, or cattle plague. Scientists and advisers are confident that rinderpest will be ultimately defeated by the target year of 2010 but plans have been drawn up to outline the way forward for those countries endeavouring to declare provisional freedom from rinderpest and for regions still waging war against remaining pockets of the disease.
Today, through progress made by the Global Rinderpest Eradication Programme (GREP), the disease has been limited to a small number of sites in Asia and Africa. But the spectre of the devastating epidemics of the past continues to be a threat as long as these few small areas continue to harbour rinderpest. So, special attention is being given to the remaining sites under the intensified Global Rinderpest Eradication Programme (iGREP), which is currently being promoted and co-ordinated by FAO.
The cost for controlling rinderpest has been high for both developing countries and donor nations: the European Commission alone has invested around US $200 million to support rinderpest control programmes in Asia and Africa in the last decade. However, the cost-effectiveness of the rinderpest eradication campaigns is demonstrated by the fact that there are only three small foci of known rinderpest outbreaks still occurring around the world. Experts estimate that it could cost as little as US $3 million each to eradicate rinderpest from these remaining pockets in southern Sudan, southern Somalia and parts of Pakistan; a relatively small price to pay for the efforts needed to finally free the world of rinderpest. "Failure to act now will mean running the risk that outbreaks of the disease will result in a much higher price tag in the future," says FAO expert Mark Rweyemamu. "For example, the rinderpest epidemic of the early 1980s was responsible for enormous losses in terms of lost livestock and income which cost US $2 billion in Nigeria alone."
The remaining foci of the disease pose a particularly grave risk to neighbouring countries that no longer experience rinderpest and who have ceased to vaccinate cattle herds against the disease. India, for example, declared provisional freedom from the disease in March 1998 and, along with other Asian countries such as Nepal and Bhutan, have taken the first steps to verify eradication by ceasing vaccination through the internationally agreed procedure known as the OIE (Office International des Epizooties) pathway. But there is particular concern in these countries for the continuing presence of rinderpest in Pakistan. The Government of Pakistan is committed to launching a national eradication programme but is seeking FAO and EU support to enable this to be put in place as soon as possible.
In Africa, the current strategy of the Pan-African Rinderpest Campaign (PARC) is for all countries, or zones of countries, free from the disease to declare provisional freedom from rinderpest in the near future. Progressively over time, the national herds of each country that has declared itself free of rinderpest will have decreasing immunity and an increased susceptibility of the cattle population to the disease. So any unchecked outbreak from a country still harbouring rinderpest could be potentially devastating in its effects. FAO's EMPRES programme, which co-ordinates the GREP, has called on all countries in a position to cease vaccination to join the OIE pathway whilst strengthening emergency preparedness as protection against the risk of re-infection of cattle herds by rinderpest.
Instability in Somalia and Sudan has made access to some livestock populations extremely difficult and there are concerns that the rinderpest virus is still circulating in pastoralist herds. However, recent advances in vaccine technologies have allowed the development and production of a thermo-stable vaccine which is tolerant to higher temperatures than previous cold-chain dependent vaccines and is more practical in areas where access is difficult and resources are limited. Molecular epidemiology, which allows the source of an outbreak to be better identified, has also allowed the better targeting of disease control strategies.
Although there is growing confidence that rinderpest only remains in these isolated pockets of Asia and Africa, other small areas in the Arabian Peninsula, northern Iraq and the Far East of the Russian Federation are still regions of uncertainty with regard to rinderpest. Vigilant monitoring and intensive surveillance is therefore vital to ensure that these areas are also of no threat. Large wildlife ruminants, such as buffalo, eland and giraffe, which are also affected by rinderpest, are also used as sentinels for the disease. Serological testing of wildlife population samples has given valuable evidence for the activity of the virus both in terms of time and location. And, as the last evidence required for the eradication of rinderpest will be from wildlife samples, those people involved in the important supporting role of monitoring wildlife will be the last soldiers to withdraw from the final battle against this disease.