SANTIAGO — Chile declared a public health alert Monday over a hantavirus outbreak that has killed three people and infected at least 10 others.

Health Minister Jaime Manalich said wildfires in the southern Bio Bio and Araucania regions have driven rats from their normal habitat into places where people live. In an interview with Chile's Radio Cooperativa on Monday, he said that he fears this may be just the leading edge of a much wider problem.

The outbreak began in the El Manzano prison, where two inmates died and 10 others were under observation.

Authorities learned on Sunday that two prison workers now have symptoms, and a person camping outside Concepcion died of the virus.

Hantavirus does not spread between humans. People catch it when they are exposed to rat droppings and urine. The early symptoms are similar to the flu, including chills, fever and muscle aches. But it can spread quickly, leading to lung and kidney failure. Once it reaches the lungs, the chance of survival can be less than 50 per cent, according to the U.S. National Institutes of Health.

In the Bio Bio region, authorities have been handing out packages of chlorine, breathing masks and pamphlets to people living near the prison in hopes of containing the outbreak.