SCIENCE / MEDICINE : Virus Threat Seen in Fish Farming Practices

Fish farming in the Third World is increasing the risk of a global influenza epidemic against which humans have no natural immunity, a report in Nature magazine warns.

Researchers said the risk comes from a new virus that could be created by the breeding of fish near pigs and poultry--a common practice in some Asian countries.

Profs. Christoph Scholtissek from Giesen University in West Germany and Ernest Naylor from the University College of North Wales said pigs were the link between influenza viruses found in poultry and those found in humans.

Their article said the link is the reason outbreaks of pandemic influenza often started in Asia. “In Thailand, for example, wide use is made of pig-hen-fish culture. The hens are in cages above the pigs which consume hen feces, and the pigs are in pens directly above fish ponds into which they defecate,” they noted.