New York City health officials announced Monday that the death toll from an outbreak of Legionnaires' disease in the South Bronx had risen to seven.

Officials had stated over the weekend that there had been a total of 81 reported cases of the disease with 64 requiring hospitalization. Of those cases, officials said that 28 people had already been discharged.

"We are taking this very seriously," Dr. Mary Bassett, the city's health commissioner, told a public town hall meeting at the Bronx Museum of the Arts, where people waited in line to get in.

The seven people who died were all older and had other health problems, officials said. 

Legionnaires' disease is caused by water contaminated with a certain bacteria being inhaled into the lungs. Symptoms include fever, cough, chills and muscle aches.

Dr. Jay Varma, deputy commissioner for disease control for the city Department of Health, emphasized that the disease was not passed on from person to person and that most people weren't at risk.

"This is still a pretty rare disease," he said.

There have been 2,400 cases nationwide this year. The legionella bacteria were discovered last week at a Bronx hotel and in equipment at a hospital.

Officials have traced the likely cause of the outbreak to cooling towers, which can release mist. They said 17 towers in the area have been tested, with five testing positive for legionella bacteria. They said at the meeting Monday that all five of the towers have been decontaminated.

In a statement, Democratic Mayor Bill de Blasio said new legislation requiring inspections, sanctions and other regulations for property owners whose buildings test positive for the disease would be presented this week to curb future outbreaks.

"Legionnaires' disease outbreaks have become far too common over the past 10 years, and the city will respond not by only addressing an outbreak as it occurs but with a new plan to help prevent these outbreaks from happening in the first place," he said.

The disease is easily diagnosed and treated with antibiotics. It poses the most risk to people who have underlying medical conditions, health officials said. Other groups at high risk for Legionnaires' disease include people who are middle-aged or older, especially cigarette smokers; people with chronic lung disease or weakened immune systems and people who take immunosuppressive drugs.

Ella Clark, 67, said she was glad she had attended the meeting but still wanted to know more about where the problem originated and what steps were being taken to address it.

"Five out of 17 is a little too much," the Bronx resident said, referring to the contaminated towers.

Officials said it would take more time and testing to figure out where the disease came from.

Kevin Woodhouse, 60, said he thought the city was doing everything it could.

"The bottom line seemed to be that everybody involved is giving it the full court press," he said.

The Associated Press contributed to this report.