Mysterious respiratory disease infects 7 in southeast Alabama, 2 dead.

Montgomery, Alabama (CBS/AP) -- A mysterious respiratory illness of unknown origin has killed two people in southeast Alabama and put five more in the hospital.

A May 21 statement from the Alabama Department of Public Health says that seven people have been admitted to a hospital with a fever, cough and shortness of breath in recent weeks.

State and local health departments are investigated the disease cluster in consultation with the Centers for Disease Control and Prevention (CDC). Laboratory samples have been obtained from all the patients and testing continues, according to the statement.

Dr. Mary McIntyre, spokesperson for the Alabama Department of Public Health, said the illness was first reported late last week and the last of the seven patients was hospitalized Monday.

McIntyre says officials hope to have preliminary results on the samples back by Wednesday or Thursday morning.

Hospital staffers have been told to wear N95 breathing masks and take other precautions when caring for patients who have respiratory symptoms. It is unclear at this time which hospital received the patients and which municipalities the illnesses were concentrated in.

"We're only aware of the Southeast, but we don't know - we haven't received reports from anywhere else," McIntyre said. "That's why we're trying to get the information out."

McIntyre said it's unclear what's causing the illness but some of the seven patients also had the flu.

The CDC referred all questions to Alabama health officials.