PANAMA CITY, Panama –– Panama declared an epidemic alert and canceled traditional Lenten carnivals in a central province after the hantavirus killed three people.

Six more people were hospitalized with the pneumonia-like effects of the virus in the central province of Los Santos, 150 miles west of Panama City, said Health Minister Jose Teran.

"This situation constitutes an extremely grave danger for the population of this province," Teran said late Thursday.

The Health Ministry said tests conducted by the U.S. Centers for Disease Control confirmed that a total of nine people – five women and four men – had been infected with the virus. The biggest outbreak of the virus to date in Latin America occurred in Chile in 1997, killing 16 people.

Authorities said they believed the infection had been spread by rats or field mice.

While the virus is not commonly spread by contact between humans, authorities canceled the planned March 4 carnival in Los Santos, which draws thousands of visitors to the region each year.

The symptoms of hantavirus include fever, muscle aches, headache, diarrhea and abdominal pain.