Legionnaires’ Disease Resurfaces in New York City

New York City has again become a significant location for Legionnaires’ disease outbreaks, marking 50 years since the illness was first identified during a major outbreak affecting veterans in Pennsylvania. Recently, bacteria associated with Legionnaires’ have been linked to five deaths and over 80 illnesses in Manhattan’s Upper East Side within just a month.

This marks the third significant outbreak in New York City over the past twelve years, following a cluster in Harlem last year that claimed seven lives, as well as a notable incident in the South Bronx back in 2015, which was among the nation’s most serious outbreaks.

“Not many cities around the world face this,” remarked Greg Rankin, CEO of a company specializing in Legionella testing.

History of Legionnaires’ Disease

The disease got its name after an unexplained pneumonia affected military veterans at an American Legion convention in Philadelphia in 1976. Dubbed “the mysterious Legionnaires’ disease” by the media, it baffled health officials for months until they identified the bacterium Legionella.

When first discovered, public health experts noted that Legionella was particularly elusive, as it thrived under conditions that differed from those favoring other bacteria. While it naturally exists in water and soil, it proliferates in warm water, especially above 90 degrees, and also thrives in corroded environments.

Federal scientists noted decades ago that Legionella tended to flourish in outdated plumbing systems and stagnant water in large air-conditioning setups. Essentially, it thrived in urban areas.

Presently, New York City has the ideal conditions for the bacteria to flourish, with its aging pipes and numerous high-rise buildings equipped with complex plumbing and air-conditioning systems.

Challenges in Combatting Legionnaires’ Disease

In response to the ongoing issues, city officials have mandated strict testing and disinfection protocols for the cooling systems of large buildings. However, some health experts express concern that this strategy may not be sufficient. They argue that focus should also shift towards plumbing systems, as conditions there can harbor the bacteria just as much as air-conditioning units can.

While New York City has one of the highest rates of Legionnaires’ cases, it’s clear that infections have been climbing across the United States. Over the past 25 years, cases nationwide have more than quintupled, though most instances involve isolated cases rather than large outbreaks. Such sporadic infections may occur when Legionella colonizes plumbing systems, showerheads, and other water sources.

The Mechanism of Infection

Legionella can develop within biofilm—a slimy layer made up of various microorganisms inside pipes and fixtures. Sudden changes in water pressure can release this biofilm, resulting in a surge of Legionella that leads to severe pneumonia.

Various activities can cause abrupt shifts in water pressure. For instance, opening fire hydrants during hot days for kids to play can disturb the balance, as can shifts in water usage in large apartment complexes.

In NYC, sporadic infections of Legionnaires’ disease have been traced back to building water systems, often when individuals inhale mist-filled droplets, particularly while showering. Occasionally, the city’s Health Department will advise residents to refrain from showering in certain buildings. Generally, healthy individuals are less likely to fall seriously ill, but older residents or those with pre-existing conditions remain at risk.

Major Infection Events

Typically, larger outbreaks are linked to mist released from rooftops. Central air-conditioning systems in large buildings create warm water, which is sent to rooftop fixtures known as cooling towers. The fans in these systems blow across the water, causing evaporation. However, these cooling towers can serve as breeding grounds for bacteria, with the resulting mist potentially infecting individuals several blocks away.

“To cultivate Legionella, the main ingredients are algae and rust,” noted Micah Curtis, a sales director at a cooling tower manufacturer. Cooling towers have previously been connected to outbreaks, including those in the Bronx and Harlem.

New York City operates close to 6,000 cooling towers, with approximately 75% of them situated in Manhattan. Health officials have meticulously documented their locations to facilitate testing during outbreaks. Following last year’s incident, property owners now must test these towers for Legionella every 30 days instead of the previously mandated 90 days.

However, Dr. Michelle Morse, who previously served as the acting city health commissioner, warned that frequent testing alone might not prevent outbreaks due to how rapidly Legionella can grow.

Recent Incident

This month, an 87-year-old resident, Christine Roussel, collapsed in her apartment while recovering from a book tour. She remained on the floor until a doorman noticed her the following day and called for help.

On the same day, Robert Goldstein, an 88-year-old Air Force veteran, developed a high fever. After some insistence from his wife, he went to the hospital. Unfortunately, both Roussel and Goldstein succumbed to this summer’s outbreak after spending over two weeks hospitalized.

“It’s something invisible, a vapor that invaded his lungs and took him away from me,” stated Ida Goldstein, Mr. Goldstein’s widow.

In response, the Health Department began testing more than 180 cooling towers from Central Park to the East River.

Initial screenings revealed that over 70 of these cooling towers tested positive for Legionella DNA, regardless of whether the bacteria were still alive. These towers were located atop apartments, schools, and major cultural institutions, such as the Guggenheim Museum and the Metropolitan Museum of Art.

Dr. Alister Martin, the city’s health commissioner, remarked that these results highlight just how prevalent Legionella is within urban infrastructure. He directed for immediate draining and disinfection of towers that tested positive, rather than waiting for further confirmation as was done in past situations.

This proactive response seemed to be effective. Most patients were diagnosed between July 2 and July 9, with no new cases reported since July 15.

For health officials, the takeaway is that cooling towers are rife with the bacteria. However, they still need to figure out the exact source of this outbreak, as they intend to match the genetic profiles of Legionella from patients with samples collected from cooling towers.

The Broader Issue

Nonetheless, this swift action won’t stop all of the 200 to 700 yearly cases of Legionnaires’ disease in New York City. A 2016 review by CDC researchers indicated that approximately one-quarter of outbreaks are tied to cooling towers, while more than half stem from potable water sources.

Dr. Michael Skelly, an infectious disease expert familiar with the 2015 Bronx outbreak, conveyed that he feels the greater risk actually comes from tap and shower water. In recent years, the Health Department has consistently identified multiple buildings with several residents affected, finding Legionella in concerning quantities in the plumbing systems.

“They keep pointing fingers at cooling towers. They keep cleaning them, yet the outbreaks persist,” Dr. Skelly noted.