NEW YORK — Legionnaires' disease is a serious type of pneumonia caused by bacteria known as Legionella.

The rare disease has caused two deaths and 58 diagnoses in New York City after an outbreak in Harlem. This is an increase from last Thursday, when one person had died and 22 people were sick.

Here's what to know about Legionnaires' disease:

Legionnaires' disease symptoms

According to the Centers for Disease Control and Prevention, Legionnaires' disease can cause pneumonia symptoms, including:

Cough

Shortness of breath

muscle aches

Headache

Fever

Who's most at risk?

“It is especially important for people at higher risk — including those ages 50 and older, cigarette smokers, and people with chronic lung disease or compromised immune systems — to get care if they have symptoms,"

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