New York City’s current Legionnaires’ outbreak appears to be ending, but how ready will we be for the next outbreak? Key questions remain as City Council squares off against Mamdani administration.
Jul. 23, 2026 — As I write this, New York City’s Department of Health and Mental Hygiene (DOHMH) has so far reported a total of 84 cases of Legionnaires’ disease arising from the Upper East Side cooling tower outbreak, with five fatalities, and seven patients still in hospital. A total of 78.6 percent of the 84 patients were hospitalized at some point in their illness. [See our tracker.] Dr. Alister Martin, the Commissioner of DOHMH, stated yesterday that the “last new diagnosis of Legionnaires’ disease was on July 15,” and that, due to remediation efforts, “We feel confident that we’ve eliminate [the] source” of the outbreak.
Some observers believed that, because PCR results are so sensitive and detect both live and dead legionella, that a sizable percentage of PCR-positive results would turn out to be culture-negative. In fact, DOHMH has so far reported culture results for 48 buildings with cooling towers that tested PCR-positive. Fully 46 of those buildings have cooling towers that are culture-positive as well.
The unspoken big picture
Water ecologists are the staffers who deal with, among other things, Legionnaires’ in cooling towers. According to William Fowler, DOHMH’s press secretary, the Department has 56 budgeted water ecologist and supervisor positions for Legionella work. Of those, 35 are on staff, 14 are in the “onboarding” process, and seven are vacant and are being recruited for.
The fact of unfilled positions and new staff in the training process has attracted much attention and criticism, although it is well known that the city’s hiring process overall is notoriously cumbersome and slow.
What has not attracted attention is the fact that a health department — as with other departments that deal with emergencies — doesn’t simply need “just enough” staff to deal with the day-to-day, it needs a staffing level that provides sufficient buffer to be able to surge response at crisis moments.
I spoke with Mitchell Stripling, director of the New York City Preparedness and Recovery Institute, based at Columbia’s Mailman School of Public Health. From about 2013 to 2019, Stripling was assistant commissioner for agency preparedness and response at DOHMH.
Stripling described a process that, over the last 25 years, has left health departments more vulnerable than ever. Sometimes, new federally mandated responsibilities came with new federal funds. But, at other times, the funding disappeared while the obligations remained. And, overall, states and cities took the opportunity of the federal funding to reduce their own financial commitment to public health.
“So,” Stripling explained by way of example, “when Hurricane Sandy hit or when Ebola threatened, a health department would get a bolus of additional funds, but that could not create or maintain the structures that you describe. And so what most health departments did over time was that they used those federal funds often to replace the loss of local or state revenue . . In many ways, public health is more fragile now than it was 15 years ago.”
The need for buffer capacity, Stripling says, is especially important given the wide range of crises that DOHMH has to mange: “The buffer capacity you described is so important when a health department is facing not just Legionella, but security preparations for the World Cup, the ongoing cyclospora investigation, Ebola tracking that has been federally required because of the Ebola outbreak in Africa, heat emergencies, air quality emergencies.”
“You know,” Stripling continued, “I think that the health department’s incident command system is balancing half a dozen things right now. And that is well above any health department’s kind of baseline capacity for response.”
Stripling acknowledges efforts by New York State and by philanthropies to boost capacity, but nothing to “meet the scale of that need.”
“We know that building just-in-time systems makes those systems more fragile. And when those systems are life safety systems, that is really what will lead to more morbidity and mortality … If you don’t have this ability to prepare, if you don’t have systems that can surge when needed, these systems will break, and it will hurt people,” he concluded.
City Council oversight and legislation
On Jul. 21, City Council Speaker Julie Menin, joined by several of her Council colleagues, held a press conference at Lenox Hill Hospital to announce that a Council oversight hearing would be held in September and that the Council was developing a legislative package to enhance Legionnaires’ response further. (Last year, the Council passed legislation to increase the frequency of required building self-inspections of cooling towers and to add to mandated treatment requirements.)
Among the issues that will be explored at the hearing will be the apparent 25 percent of buildings that did not submit required reports on cooling towers (some of which might be explained by a tower not being in operation when a report would otherwise have been called for), and how DOHMH has handled and continues to handle non-compliance over the course of the summer.
Also on the list is increasing the amount of the fines to be levied for non-compliance with Legionnaires’ testing and treatment requirements (both proactive and remedial). When the press conference concluded, I spoke with Council Member Lynn Schulman, the chair of the Council’s Committee on Health and the lead sponsor of the 2025 legislation.
Under Title 24, Section 8-09 of the Rules of the City of New York, fines for an initial violation relating to cooling tower maintenance, compliance, and reporting are either $1,000 or $2,000. Penalties can be doubled for repeat violations.
“If you charge a building $2,000,” Schulman told me, “it’s the cost of doing business for them. It’s like somebody getting no-parking tickets. So we have to [raise the penalties.] When we did the legislation, we thought that was enough. But it’s not.”
Another area of inquiry will be DOHMH communications with the public. I spoke with Menin directly following the press conference and asked her if she thought that DOHMH should release more aggregated (non individually identifiable) information about the set of Legionnaires’ patients, such as how many have had to be treated in the ICU. “Yes, yes,” she replied. (DOHMH does not provide this information or data on how many patients have been put on ventilators.)
The Department has previously invoked a non-specific privacy rationale. I asked Stripling, the former DOHMH official about this. He asserted that there were privacy concerns, but, when I pressed him on the mechanism of how privacy of individuals would be compromised by the release of aggregated information, he said only that releasing the information could encourage people (presumably both civilians and media) to besiege hospitals and their ICUs for such information, or to try to confront visitors. Frankly, it is unclear either how that would be permitted to play out, or why not releasing information would prevent interested individuals from engaging in such tactics. In speaking with a number of public health experts, none has explained how a privacy breach would realistically follow from the described aggregated disclosure.
I also asked Menin (and, separately, DOHMH) whether there have been to date any confirmed cases associated with the Upper East Side outbreak where the patient neither resided in the three-zip-code vigilance area (10028, 10128, and 10075), nor worked in the vigilance area, nor traveled to the vigilance area. Menin said that she asked but was not given the information. DOHMH has not responded directly to my question.
DOHMH has also not reported each cooling tower’s concentration of legionella based on the culture results. DOHMH explained that all cooling towers with positive culture results had either been already fully remediated based on PCR-positive testing or, in the few cases where PCR results were negative but culture results were positive, have now been remediated. In other words, even though the City’s rules identify four different levels of concentration,1 each with a corresponding corrective action, DOHMH has already required the corrective action associated with the highest level of concentration.
On the other hand, concentration levels directly indicate how out-of-compliance (or not) a particular cooling tower had become, and might suggest the level of inattention to required protocols that a particular building owner manifested. I asked DOHMH to respond to these concerns specifically, and it has not yet done so.
Additional issues raised and addressed
At Speaker Menin’s press conference, multiple speakers addressed the question of whether there are steps that an individual member of the public could take to prevent infection with legionella stemming from a cooling tower outbreak, including whether the wearing of masks is useful.
DOHMH has said throughout the outbreak that there is no evidence that the wearing of masks is helpful. Council Member Schulman, the Health Committee chair, told me that her understanding was that that doing so “does not help.”
When I asked her what if it were the case that the only thing an individual can do is to monitor for symptoms vigilantly, she confirmed, “That’s exactly what people can do,” adding that one can also find out from building management the status of one’s own building. (DOHMH press secretary Fowler said, “Because of the way that mist can travel from a cooling tower, there is no additional risk to being in or near buildings that tested positive compared to anywhere else in the investigation area. ”)
What DOHMH has not yet done in response to inquiry is to state flatly what I believe to be the case from my reporting: that there are indeed no steps an individual can take to prevent the disease.
- 1.
See page 10, Table 8-1.
A central focus of Menin’s presentation, echoed in an op-ed she has written for the New York Post, is the complaint the DOHMH did not proactively remediate cooling towers prior to getting PCR test results. She has used different formulations to make the same point (the op-ed has it as “proactively disinfect cooling towers throughout the affected area”; during the press conference, she asked rhetorically, “[R]ather than wait for test results to come back, why not proactively disinfect so that more New Yorkers and, in this case, more East Siders did not become sick?”).
After the press conference, I asked Menin whether she was familiar with any precedent for prophylactic remediation2 (that is, pre-testing). She said she was told by a former Council Member that there was such a precedent on the East Side “years ago.” Menin’s office did not respond to my requests to provide specifics about the geographic area and year of claimed outbreak.
DOHMH’s Fowler said that universal prophylactic disinfecting “has never been the Department’s protocol,” adding that, “For the first time, in this cluster, we ordered all buildings with positive initial screening results to fully drain, clean, and disinfect their cooling tower. ”
In addition, Fowler said that blanket remediation can have unintended consequences, including risks of diverting the strategic focus and resources of the agency and the capacity of remediation vendors away from the cooling towers most in need of remediation. Moreover, he said, overuse of biocide can damage cooling tower equipment, paradoxically creating greater circumstances in which legionella can grow more effectively. Stripling echoed the concern about managing limited agency resources strategically.
Perhaps the most provocative part of the press conference was Menin’s suggestion that DOHMH’s delay had cost lives. In response to a reporter’s question as to whether it was possible to know that for a fact, she did initially provide the caveat that “we don’t have that information,” but then added, “[L]et’s just talk about common sense — if they had proactively disinfected, less people would have become sick.”
When asked by another reporter later in the press conference whether she personally believes that “the death toll is as high as it is because the Health Department did not order mandatory blanket cleaning of all building towers on the Upper East Side,” she responded, “I believe the Health Department should have issued the Commissioner’s Orders to proactively disinfect and that would have prevented what we saw in terms of the number of deaths and the number of people who contracted it.”
Fowler responded that, “There does not appear to be any evidence that this is true.” He said that DOHMH “immediately acted [to begin testing] on July 2 once epidemiologists identified two cases within a tight frame in the same area.”
What next?
Even if Commissioner Martin is correct that the source of the Upper East Side outbreak has been eliminated (as he appears to be), we are not necessarily out of the woods. Cooling season has a couple of months to go, and the Upper East Side is just one neighborhood of many. Any cooling tower that is not maintained to a high standard can become a vector (whether in New York City or elsewhere). There is no “immunity” conferred by the fact that one outbreak has already occurred in 2026.
The hearing to be held in September will likely vindicate DOHMH’s substantive approach to the outbreak (and perhaps require its codification) and likely result in new legislation to increase fines for non-compliance and create some sort of as-yet-unspecified hotline into which concerned New Yorkers can call. Whether other enhancements to public communications are made; whether there is a negotiated or mandated increase in the frequency and intensity of DOHMH inspections; and whether DOHMH finds itself the beneficiary of modestly enhanced funding all remain to be seen.
The implementation of robust funding to allow for “buffer capacity,” though, will almost certainly not be part of any package that emerges.
Corrected Jul. 23, 2026 to clarify that the 56 water ecologist staff and supervisor positions are for Legionella work specifically.
- 2.
Menin used the term “disinfect” several times. It is not clear whether that was meant to be a general term for doing all that is necessary to make sure a cooling tower is clear of legionella (DOHMH has ordered draining, cleaning, and applying biocide), or whether she meant just the step of adding biocide.