Control of animal epidemic slowed human illness

Control measures implemented in response to a 2001 outbreak of foot-and-mouth disease among livestock in England and Scotland apparently helped reduce by a third the incidence that year of a parasitic illness in people, researchers in Scotland have found.

To stamp out the foot-and-mouth outbreak, officials sacrificed more than 1 million sheep and cattle in the affected areas of Scotland and restricted the transportation of other animals. Regulations also prevented people from making unnecessary visits to farms.

Those measures apparently slowed the spread of Cryptosporidium parvum, a diarrhea-causing parasite that can spread from farm animals to people via water or soil tainted with feces. In Scotland’s foot-and-mouth–affected areas, 60 percent fewer Cryptosporidium infections occurred in people than was the yearly average from 1994 to 2000, Norval Strachan of the University of Aberdeen and his colleagues report in the September 1 Journal of Infectious Diseases. There wasn’t a significant fall in Cryptosporidium incidence in areas of Scotland free of foot-and-mouth disease, where the response to the outbreak was less aggressive.

The restoration of good livestock health had a predictable side effect: Cryptosporidium infections rebounded in Scotland in the year following cessation of outbreak-control measures.

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