Origin of fungal disease outbreaks in marine mammals

In the early 2000s, a fungus infected hundreds of animals and people in British Columbia and Washington state (USA).

The disease also kills porpoises and dolphins in the Salish Sea, the scientists found . The team said it is likely that this fungus affected whales earlier than humans.

C. gattii likely appeared in the Pacific Northwest in the early 1900s.

Research published in the journal Diseases of Aquatic Organisms explored the effects of human-induced changes on land on aquatic animals, specifically in the case of the fungus Cryptococcus gattii .

Led by the University of California, Davis, a team of scientists from Canada and the Pacific Northwest has compiled the history of fungal outbreaks in marine mammals. They gathered and analyzed data collected over decades by veterinarians, microbiologists, and marine mammal biologists.

The fungus C. gattii can cause lung and brain disease. This fungus exists in the soil and is often found in tropical and subtropical forests. C. gattii likely appeared in the Pacific Northwest in the early 1900s. However, how this fungus appeared is not well understood.

Since 1999 on Vancouver Island, humans, pets, and wildlife have been infected with C. gattii. After that, the fungus gradually affected individuals living on the continents of British Columbia, Washington, Oregon and California. Researchers found that 42 porpoises and porpoises in the Salish Sea died from this fungus.

Construction, deforestation, and other activities that disturb the soil can cause the release of C. gattii spore gas, which, in turn, infects humans and animals that inhale the spores.

Lead author Sarah Teman of the University of California Davis School of Veterinary Medicine said : 'As the environment is altered in unprecedented ways, many diseases can affect humans and wildlife. wild'.

Marine mammals that died of C. gattii are found in near-terrestrial areas. This suggests that fungal spores exist on the surface of the sea - where porpoises and dolphins inhale when emerging to breathe.

The researchers also found evidence that the first C. gattii infection in the Pacific Northwest may have occurred in a dolphin in 1997. This was two years before the field was identified. The first human case in the area was infected with C. gattii in 1999.