SALINAS, Calif. -- A public health warning has been issued for a potentially deadly illness that's on the rise in Monterey County.

County health officials said they're seeing an alarming number of cases of valley fever, also known as cocci. The illness is a fungal infection that affects the lungs.

Officials said during all of last year, there were 22 cases of valley fever reported in Monterey County. Less than two months into this year, there have already been more than a dozen cases reported.

Valley fever is an airborne illness that is caused by exposure to a fungus that lives in the soil. Those who work outdoors near soil are most prone to getting the infection.

The infection causes flu-like symptoms, such as fever, cough, headache and fatigue.

Health officials said they're concerned because the disease is not common to the area, and if the symptoms are not treated properly, the problem could get worse.

"We're seeing a lot of people showing up to the doctor's office after having a cough for two to three weeks and have taken multiple cases of antibiotics and not gotten better," Monterey County Health Department spokeswoman Linda Velasquez said.

If untreated, valley fever can turn into severe pneumonia or pulmonary disease.

Officials are in the process of talking to those affected to see if there is a common thread.

Doctors said valley fever can only be treated with fungus-killing medicines.

Anyone who's had a cough for more than two weeks is encouraged to have their doctor check for signs of valley fever.

Resources:

More about valley fever: www.dhpe.org

Valley Fever Center For Excellence: www.vfce.arizona.edu