Legionnaires’ Disease Outbreak in New York City

A recent outbreak of legionnaires’ disease, which, although rare, is a serious form of pneumonia, underscores the increasing risks posed by this microbe in a warming climate.

So far, at least 28 individuals have fallen ill in an outbreak that’s centered on the Upper East Side, an affluent area nestled between Central Park and the East River in Manhattan. To combat the outbreak, health officials have tested water samples from nearly 160 cooling towers in buildings throughout the area.

Dr. Alister Martin, the commissioner of New York City’s health department, remarked, “This is now a subtropical climate. It is absolutely true that climate change is worsening our exposure and increasing the chances for legionnaires’ disease clusters like we’re seeing today.”

According to Martin, the city is pursuing an “aggressive” response, noting that developing legionnaires’ disease is still “extremely, extremely rare.” He revealed that he ordered the draining, cleaning, and disinfection of cooling towers in at least 19 buildings, which another official referred to as “buildings of interest.” Further extensive testing will be necessary to identify the building that might have triggered the outbreak.

Legionnaires’ disease stems from the bacterium Legionella pneumophila, commonly found in warm water settings. Typically harmless, it becomes a threat when inhaled in the form of vapors or mists.

This bacterium can lead to a range of illnesses, varying from mild conditions such as Pontiac fever to severe legionnaires’ disease, which presents symptoms including cough, fever, headaches, muscle aches, and shortness of breath. Although legionnaires’ affects fewer than three people per 100,000, it can have a fatality rate of about 10% among those diagnosed.

The name “Legionella” originated from the first identified outbreak in 1976, involving veterans from the American Legion who gathered in Philadelphia.

Since that incident, the bacterium has been linked to a growing number of outbreaks around the world, from New York to Melbourne, Lombardy in Italy, and Lincoln, New Hampshire. Factors such as aging urban infrastructure, inconsistent maintenance, and vulnerable populations can exacerbate these outbreaks.

George Yates, a 54-year-old Harlem resident who contracted legionnaires’ in an outbreak in Washington Heights back in 2018, shared his experience: “You’re walking down the street minding your own business, breathing in the air, and the air may be contaminated from a cooling tower you can’t even see.” He didn’t live or work in Washington Heights but believes he might have encountered the bacteria while working as a ride-share driver. He was hospitalized for five days but eventually recovered.

Dr. Benjamin Wyler, an emergency medicine physician at Mount Sinai Health System, advises residents not to live in fear. “But if you’re developing symptoms like a febrile illness and cough or malaise, gastrointestinal issues, you should maybe have a lower threshold to seek care,” he added.

The current outbreak spans three affluent zip codes on the Upper East Side. Nonetheless, historical data indicate that legionnaires’ disproportionately impacts those in poverty and Black Americans, which has frustrated community leaders.

Marquis Harrison, chair of a Manhattan community board in Harlem, expressed concern at a public meeting in March, saying, “I started to believe that Legionella only knew Black and brown neighborhoods. We only saw it in the South Bronx and in Harlem, and only communities of color.”

While Dr. Martin indicated that New Yorkers would soon learn the names of buildings required to clean their cooling towers, the specific source of the outbreak might remain unidentified.

Identifying the culprit will involve culturing water samples to verify if the Legionella from PCR tests was a live colony. Additionally, lab technicians must sequence the genomes and compare them with samples from legionnaires’ patients. Notably, medical professionals typically rely on urine tests for diagnosis, which means some patients may not have had sputum samples collected.

The health department still has substantial work ahead, and it could take a month or longer to publish investigation findings. In fact, many smaller outbreaks go unsolved, as noted in CDC reports.

Jory Lange, a food safety attorney in Houston, lamented, “Every summer we’re getting calls from people in New York who unfortunately are contracting this disease.”

Even once the investigation concludes, the implications of climate change will likely still encourage conditions that favor Legionella’s growth.

Legionnaires’ disease has been connected to various unexpected sources left stagnant by industrialization, including hot tubs, water jet cutters, floor scrubbers, and fountains. One study indicated that truckers were particularly vulnerable due to their use of subpar windshield cleaners in their vehicles.

Dr. René Najera, public health director at the College of Physicians of Philadelphia, stated, “The bacteria don’t care. If they see a warm spot with water, they’re going to thrive and multiply.”

“I don’t know if we’re past the point of no return on climate change,” he continued, “but certainly, it’s not helping.”