The international early warning system for animal disease outbreaks is scheduled for a full overhaul within 1 year, a change the World Organization for Animal Health (OIE, for Office International des Epizooties) will discuss this week.

The OIE now divides diseases into List A and List B. List A includes foot and mouth disease, while List B includes diseases such as anthrax or bovine spongiform encephalopathy (BSE).

"The intention was to give a degree of urgency to List A diseases, because of their rapid spread and significant economic importance. Countries had to report an occurrence on those diseases very rapidly. List B were either less important economically or had slower degrees of spread," Alex Thiermann, president of the OIE code commission responsible for setting animal health standards, told The Scientist. "With time, the system was misinterpreted that diseases on List A were more important than List B," he added.

OIE decided last year to replace these two lists with a single list. The organization plans to suppress Lists A and B in January 2005 and adopt the new list by 2005. This week, delegates from OIE's member nations will discuss what kinds of diseases belong on the list and how urgently OIE should be notified of outbreaks.

One of the main reasons for the changes is how diseases such as BSE, Nipah, or Hendra, which affect humans as well as animals, "appeared for the first time but were not on the list of OIE, so were not reported immediately," said Arnon Shimshony, associate professor at Koret School of Veterinary Medicine at Hebrew University in Jerusalem and ProMED-mail animal disease and zoonoses moderator. "These changes are meant to prevent such situations. Zoonotic diseases get a special place, which is important."

In the proposed system, OIE would be notified immediately of the first occurrence of a listed disease in a country or region or of a sudden and unexpected increase in morbidity or mortality caused by an existing listed disease, among other signal events.

The main criterion for a disease to be placed on the final list in the proposed changes is its potential for international spread. Other criteria include a capacity for significant spread within naive populations and the potential to spread to humans.

"I think the life science community can have quicker access to epidemiological changes in disease this way, be more able to benefit from animal health reporting," Thiermann said.

"I think the intentions behind the changes are good," said Jon Epstein, veterinary epidemiologist at the Wildlife Trust's Consortium for Conservation Medicine in Palisades, NY. "The big challenge is going to be compliance. You have 166 member nations having to conduct surveillance and report on these diseases. It will take a while to get up and running. Once it's up, it will probably be better than before."

An OIE initiative for capacity building in developing countries will accompany the new system, "to go and teach this new method so they can be better prepared to submit data," Thiermann said. OIE will also replace the traditional submission of reports by fax with new software that will allow submission of information on its Web site.

The new system "may help draw more funding by creating a greater sense of urgency," said Epstein. "Researchers who may have worked with what were formerly List B diseases will benefit from a unifying list that considers all diseases to be of the same importance in terms of reporting."

Peter Daszak, director of the Consortium for the Conservation Medicine, called the changes "a great move."

"Without being critical, from the wildlife side of things, I think OIE doesn't fill the role as well we'd like with monitoring wildlife. Wildlife's not their remit; it's domestic animals and livestock. But we're seeing diseases coming from wildlife causing conservation and economic and health issues," Daszak told The Scientist. "We'd really like to see APHIS [Animal and Plant Health Inspection Service] or OIE or an international group seriously consider making more wildlife diseases notifiable."