Symptoms of Legionnaires’ disease include headache, fatigue, loss of appetite, confusion and diarrhea. Symptoms appear between 2-10 days after exposure to Legionella bacteria.

“I want to make clear that this is a common pneumonia, one which is readily treated,” Bassett said, adding it’s “Especially important for people to seek care early, and especially important for health care providers to be aware that we are seeing these cases.”

Legionnaires’ disease can usually be traced to places favorable to Legionella growth such as cooling towers, hot water tanks, whirlpool spas, hot tubs, humidifiers and condensers in large air conditioning systems. It is not spread by human contact.

The health department said many of the cases are located in the Mott Haven, High Bridge, Morrisania and Hunts Point sections of the Bronx, Gainer reported.

Legionnaires' Disease Outbreak In South Bronx Sickens 31

Legionnaires’ is treatable if detected early.

“Thank God this is a disease that can be treated, and the important thing is early detection,” said Mayor Bill de Blasio.

“Seek care early, don’t put it off, go to your doctor,” Bassett said. “This is a common and readily treated pneumonia.”

The outbreak has some residents in the South Bronx on edge.

“It’s scary, you know. I haven’t been feeling well myself lately, me and my family,” said Michael Perez.

“I’m running straight to the doctor,” said one man.

“Makes me nervous,” another man said.

But one man, John Rouse, was furious about the outbreak. He told CBS2’s Valerie Castro that his brother died of the disease in April.

“I don’t think it’s common for an otherwise healthy 52-year-old man to pass away in 2015, from Legionnaires’ disease,” he said, “What if it turns out that their deaths are related to his on April 30? Are you going to tell me that wasn’t preventable?”

James Rouse worked in the South Bronx as a music teacher. His family now wonders if his death could be related to the most recent cases.

They claim that when they went to the Department of Health for an investigation, they didn’t get one.

“I know the mayor and commissioner of health doesn’t want to start any kind of panic about this, but I will tell you, based on our experience, that they are completely underplaying the condition as it currently exists,” he said.

The Commissioner of Health said that the cause of the outbreak was unknown, but under investigation.

The Rouse family still wants answers for their own sake, and the rest of the public.

“We’re going to do everything we have to do to make sure that my brother gets the justice he deserves, and if it was avoidable, that it never happens to anyone again,” Rouse said.

The outbreak follows one in the Bronx back in December and January. Twelve people were diagnosed with the disease, eight of which were in Co-Op City.

Preliminary results showed the cooling towers at a housing complex tested positive for the bacteria and they were decontaminated, Gainer reported.

A spokesperson for the Department of Health said they couldn’t comment on individual cases and said that because bacteria can come from many sources in the environment, it is uncommon to identify the source of an individual case.

For more information about Legionnaires’ disease, click here.