Three people in Maine have been infected with active tuberculosis, the world’s deadliest disease, according to health officials who raised alarms Friday.

There was no connection between the three patients, all of whom were in the Portland area, suggesting they were all infected by different sources, according to the Maine Center for Disease Control and Prevention.

Health officials are working to identify and screen anyone who came in contact with the three individuals with the disease, a CDC spokesperson said, according to the Portland Press Herald.

The bacterial infection kills by destroying lung and organ tissues, leading to respiratory failure and organ damage. It can also wreak havoc on the spine, kidneys and brain.

Symptoms include a persistent cough, sometimes bringing up blood and mucus, chest pain and fever. 

Tuberculosis kills more people than any other disease, claiming about 1.25 million lives worldwide every year, largely in developing countries, according to the World Health Organization.

A total of 565 people died from the disease in the US 2022, according to the most recent available death toll data.

Cases of the disease are on the rise in Maine, although there are no current outbreaks in the state.

So far this year, 28 cases have been reported in the state through the end of July, according to the CDC.

The three active cases in Maine are not genetically linked, meaning they were not transmitted from one person to another, said Lindsay Hammes, spokesperson for the Maine CDC.