In Good Health

A new Nature study has yielded more evidence that biodiversity reduces the spread of disease. In an analysis of hundreds of California wetlands, researchers found that amphibians in areas with more amphibian species were much less likely to become infected with a parasite.

The parasite, Ribeiroia ondatrae, kills and causes deformities in amphibians and can be transmitted by snails. The team studied 345 wetlands, examining more than 24,000 animals that could act as hosts for this pathogen. In more diverse wetlands, the transmission rate from snails to amphibians was 78 percent lower, the researchers report.

The team also studied disease transmission in the lab and found that increasing the number of species from one to three made the transmission rate drop by 64 percent. Then the researchers created outdoor artificial wetlands with varying amounts of biodiversity. The tanks with four host species had about half as many infected animals as those with only one species. Roberta Kwok | 18 February 2013

Source: Johnson, P.T.J. et al. 2013. Biodiversity decreases disease through predictable changes in host community competence. Nature doi: 10.1038/nature11883.

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