Showing posts with label legionella. Show all posts
Showing posts with label legionella. Show all posts
Tuesday, December 27, 2016
Preventing Legionnaires’ Disease in Healthcare Facilities Part 2 How Our Legionella Experiences Shaped our Prevention Approaches Safe Healthcare Blogs CDC
Preventing Legionnaires’ Disease in Healthcare Facilities Part 2 How Our Legionella Experiences Shaped our Prevention Approaches Safe Healthcare Blogs CDC
Preventing Legionnaires’ Disease in Healthcare Facilities Part 2: How Our Legionella Experiences Shaped our Prevention Approaches | Safe Healthcare | Blogs | CDC
Preventing Legionnaires’ Disease in Healthcare Facilities Part 2: How Our Legionella Experiences Shaped our Prevention Approaches
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Guest Author: John Letson, Vice President Plant Operations, Memorial Sloan Kettering Cancer Center
Memorial Sloan Kettering Cancer Center (MSK) has a 470 inpatient bed hospital, outpatient clinics, and research facility headquartered on the upper east side of Manhattan, with additional outpatient treatment centers in Brooklyn; Long Island; Westchester County, New York; and New Jersey. The well-being of our patients is the primary concern of all doctors, nurses, and staff. The at-risk patients at MSK basically are in two groups. First, cancer patients receiving chemotherapy, including those with combinations of factors placing them at greatest risk, e.g. a patient who smokes and has respiratory issues in addition to having a cancer for which they are receiving chemotherapy. Second, bone marrow transplant patients. The majority of patients diagnosed at MSK with community acquired Legionella in the past have been bone marrow transplant patients. As cancer care continues to move to more outpatient treatment plans, all building owners need to be cognizant of the dangersLegionella poses. It is important to be proactive in preventing the bacteria from propagating in building water systems to preserve the health and safety of everyone.
For more information about MSK and background on our successful Legionella water management program, read my blog entry.
EXPERIENCE CHANGES THE APPROACH
One of the most feared environmental scenarios in healthcare, would be to have a Legionellaoutbreak. In addition it can be quite alarming when one encounters an “outbreak” of consistently positive environmental cultures. MSK has not experienced any Legionella “outbreaks” where tests show consistent levels of positive colony forming units at many multiple distal sites and buildings. But, MSK has had instances when we had a number of positive Legionella test culture results near locations where patients tested positive for Legionella. The resultant circumstances are the same whether wide spread in a general population or isolated in an at-risk population. The resources required during any outbreak scenario will vary. So here is a brief history of MSK’s experience with positive culture results and the ensuing changes that occurred in mitigation response activities, long term mitigation activities, and the evolution of testing and monitoring.
In 1999 MSK experienced a Legionella positive patient at the same interval as a positive environmental shower culture result and a timeline that suggested it was hospital-acquired. The patient was a bone marrow transplant patient and the Legionella types from the patient and shower were the same. At the time it could not be proven that the patient’s disease was hospital-acquired. Following this event, in 2000, MSK selected and implemented copper-silver ionization as a long term mitigation methodology on the potable hot water system in all in-patient areas. We also adopted a zero tolerance for anyLegionella in any water system. As a result of this long term mitigation strategy, positive cultures were eliminated for the next seven years until November 2007, when multiple environmental test culture results came back grossly contaminated for Legionella. This was strange because we went from no positive cultures to such a high level in a short period, so we sent samples to the same lab for retest; as well as to a second, different lab. The same lab (as the previous samples were sent to) report came back contaminated again, but the new lab report came back all negative. We performed mitigation anyway, retested (results negative again), and returned to service. MSK changed labs following this event. This experience validated the importance of using a lab knowledgeable in testing protocols for Legionella or one listed as being CDC ELITE certified.
MSK experienced another positive culture on September 2, 2010. We performed mitigation in this case sanitizing the affected potable water tanks, and retested which came back negative, and were returned to service. While we did not make the correlation at the time, this positive culture was attributable to heavy rain activity during the end of August 2010.
Another positive culture occurred almost one year later. There was one positive culture on September 7, 2011, and one positive case at the same time; both Legionella pneumophila serogroup one. We performed mitigation, retested which came back negative, and returned to service. On subsequent NYC Department of Health Pulsed Field Gel Electrophoresis (PFGE) the testing showed the serogroup in the environmental culture and patient culture were different, so the case was concluded as community-acquired. Similar to the previous event we noted increases in positive cultures in potable water tanks following heavy rain. This was observed at times following heavy thunderstorms or in this instance hurricane activity. This was thought due to the increased runoff and turbulence into open water reservoirs and settling ponds. The runoff which may have washed and disturbed bacteria and organic material from soil and Legionella from biofilms into the source water. Increased organics and pathogen content overwhelms oxidizing biocides and other water purification methods, permitting some bacteria to survive and enter the water system. The positive environmental cultures of September 7, 2011 were directly attributable to hurricane Irene which hit the New York area in late August. As a result, we now test potable water storage tanks a week to ten days after heavy rain events over two inches in order to provide proactive mitigation if required.
There are additional affects an institution could experience based on positive patient cases of Legionella; even if the case is community-acquired. So how does an event change views and practices around potable water safety? Patients and staff have a lack of confidence in the potable water source and utility. Mitigation and extended monitoring is required to reinforce that water is safe when others feel it may not be. Everyone feels at risk—not just the patient. Our experience is staff become highly sensitive and concerned about the level of risk from the water supply.
LONG TERM REMEDIATION
As stated earlier, in 2000 MSK adopted and maintained a zero tolerance policy for Legionella. We adopted the policy in conjunction with implementation of copper-silver ionization on the potable hot water in all in-patient areas. Any positive culture at minimum requires a retest and in some cases enhanced mitigations of hyper-chlorination and flushing, increased ionizer levels, and a second retest to confirm effectiveness. We accomplish and maintain this policy by continually performing:
- Risk analysis is done in conjunction with the infectious disease department to identify potential sources of bacteria and outline monitoring and mitigation responses.
- Regular mitigation and maintenance including potable tank cleaning, riser flushing, cooling tower cleaning and chemical water treatment. In the case of cooling tower water treatment, we maintain the zero tolerance due to our patient population instead of under the 1000CFU/liter OSHA standard.
- Copper-silver units require regular cleaning, monitoring (testing), maintenance, and occasional repairs to be continually effective. We rebar our units every 18 to 24 months. The copper-silver units in our view are the closest thing to plug and play you can get.
- Regular testing is key to the success or failure of any water treatment program. It qualifies the effectiveness of any mitigation and enables a proactive response to a positive culture.
- Monitor and qualify new construction; new construction areas are a potential source of Legionella due to water being shut off for extended periods creating dead legs and any dirt or debris that may be left in the piping during construction activities. MSK’s process is to flush, sanitize, and test prior to placing new piping in service.
TESTING, TESTING, TESTING
Testing is key to success. We have always advocated testing of water systems including potable water tanks, random potable water distal sites, specifically hot water in showers, and cooling towers. Some states mandate testing dependent on patient population. State of NY requires quarterly water system testing where immune-compromised and transplant patient populations undergo treatment. In our experience in the past 16 years, testing has served to exonerate MSK when serogroup between patient case and cultured distal sites did not match.
Let your testing evolve to suit your conditions. MSK’s testing began and evolved as follows:
- Potable water tanks were originally tested annually, which evolved to quarterly to be consistent with all other testing. Following two sequential years of a positive culture in 2010 and 2011, we now do weekly testing for a month following a rain event in excess of 2 inches or a hurricane as it was determined that there were elevated counts following major runoffs.
- Random potable hot water at shower distal sites began and remains at quarterly intervals. Copper-silver ionization systems continue to provide outstanding results since installed in 2000. At that time, distal site random cultures previously consistently positive became negative in just two weeks and have remained that way since. We take both a bulk water sample and a swab at each site and send out 20 sites per quarter.
- We do additional potable water samples for copper and silver levels once a month to ensure the levels are maintained within range.
- Cooling towers began quarterly; we changed to monthly from June to September as we kept getting positive cultures in the 3rd quarter. Monthly testing during the cooling season allows mitigation to be more real-time and has eliminated most September positives.
- All testing is completed at a 3rd party lab. We use one of the most well recognized labs on the east coast.
ASHRAE 188 defines a systematic approach similar to what has been done effectively at MSK for the past 16 years.
The CDC’s toolkit, Developing a Water Management Program to Reduce Legionella Growth & Spread in Buildings, reinforces and breaks down ASHRAE 188 into practical action based guide to help building and healthcare providers develop new policies and methodologies to proactively prevent this disease. Having gone through these steps years before, due to our patient population, MSK does not view the standard as added work or responsibility, only a reaffirmation that what we have done here for years is the right thing to do.
Categories Healthcare-associated infections
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Thursday, October 27, 2016
Two Related Occupational Cases of Legionella longbeachae Infection Quebec Canada Volume 22 Number 7—July 2016 Emerging Infectious Disease journal CDC
Two Related Occupational Cases of Legionella longbeachae Infection Quebec Canada Volume 22 Number 7—July 2016 Emerging Infectious Disease journal CDC
Two Related Occupational Cases of Legionella longbeachae Infection, Quebec, Canada - Volume 22, Number 7—July 2016 - Emerging Infectious Disease journal - CDC
Volume 22, Number 7—July 2016
Dispatch
Two Related Occupational Cases of Legionella longbeachae Infection, Quebec, Canada
On This Page
- The Study
- Conclusions
- Suggested Citation
Marianne Picard-Masson
, Élisabeth Lajoie1, Judith Lord1, Cindy Lalancette, Geneviève Marchand, Éric Levac, Marc-André Lemieux, Patricia Hudson, and Louise Lajoie
, Élisabeth Lajoie1, Judith Lord1, Cindy Lalancette, Geneviève Marchand, Éric Levac, Marc-André Lemieux, Patricia Hudson, and Louise LajoieSuggested citation for this article
Abstract
Two patients with no exposure to gardening compost had related Legionella longbeachae infections in Quebec, Canada. Epidemiologic investigation and laboratory results from patient and soil samples identified the patients’ workplace, a metal recycling plant, as the likely source of infection, indicating a need to suspect occupational exposure for L. longbeachae infections.
Several Legionella species can cause legionellosis, which results in influenza-like illness (Pontiac fever) or pneumonia (Legionnaires’ disease) (1,2). L. pneumophila, which is mainly transmitted from aerosolized water, has been the principal Legionella species reported from Canada (3). Unlike L. pneumophila, L. longbeachae is highly adapted to the soil environment and primarily transmitted from potting soils and compost (2).
During summer 2015, a regional public health authority in Quebec, Canada, received reports of 2 cases of pneumonia attributable to L. longbeachaeinfection. These cases occurred 1 month apart in persons who shared the same workplace. We conducted epidemiologic and environmental investigations to identify the source of infection and propose appropriate control measures.
The Study
On July 3, 2015, the provincial public health laboratory (Laboratoire de santé publique du Québec [LSPQ], Sainte-Anne-de-Bellevue, Quebec, Canada), informed the regional public health authority (Centre intégré de santé et de services sociaux de la Montérégie-Centre, Longueuil, Quebec) about a case ofL. longbeachae serogroup 1 infection. The investigation team included members with expertise in infectious diseases and in occupational and environmental health. Public health experts from the Institut national de santé publique du Québec (Quebec City, Quebec), the Institut de recherche Robert-Sauvé en Santé et en sécurité du travail (Montreal, Quebec), and the LSPQ joined the investigation team of the regional public health authority. The investigators questioned the patient by using a standardized epidemiologic questionnaire and explored potential relationships between the patient’s illness (i.e., clinical manifestations, laboratory results, and diagnosis) and personal factors (i.e., demographic, behavioral, and medical risk factors) and possible exposure sources. During the investigation, another worker from the same workplace was hospitalized with severe pneumonia, and the public health team recommended testing for L. longbeachae. On July 20, 2015, the LSPQ confirmed L. longbeachae serogroup 1 infection for the second patient, and the investigation team questioned this patient by using the same standardized epidemiologic questionnaire answered by the first patient. No other causal organism was identified for either patient.
A lag of 1 month separated onset of symptoms in the 2 patients. Both had severe pneumonia that required admission to intensive care. They recovered and returned to work a few months later. Both had personal risk factors for Legionnaires’ diseases. However, neither had a history of travel, gardening, visits to gardening centers, or exposure to hanging plant pots or compost. Both worked at the same metal recycling plant for many years and shared no nonprofessional activities. One was a shredder operator at a fixed work station; the other was responsible for machinery maintenance throughout the plant (3,750 m2 in size); the only shared spaces were the locker and lunch rooms. Their work shifts overlapped for a few hours. The company, which employed ?25 workers, has been in operation for >40 years and had no prior case of legionellosis.
On July 8, 2015, the regional public health authority investigated the workplace and assessed the industrial processes. Trucks containing cars and other bulk metal materials unload at the site. An industrial grapple clamps the materials and feeds them to a shredder. Any overload is stacked until it can be processed. Diverse metals are then sorted out and sold. The business operates during April–December.
The investigation identified different sources of soil exposure. First, most of the site lies on bare ground. A tanker truck regularly sprinkles water to control dust. Second, a conveyor belt with foam residue and other debris generates aerosols that contain soil particles. However, employees are not allowed near the conveyor belt when it is operating. Third, some cars are reportedly filled with soil by suppliers to increase weight and raise selling value.
On July 31, 2015, multiple soil samples were taken from a workplace area where the soil could have been at higher risk for L. longbeachae contamination (i.e., because of greater-than-usual humidity, less exposure to wind, and less ultraviolet exposure from the sun). A control sample was taken from an area of undisturbed soil in this workplace. Proper sterilization of equipment was ensured between collections of samples. Sixteen randomly located sites (each 4 m2) were sampled, including the control site.
The Institut de recherche Robert-Sauvé en santé et en sécurité du travail obtained an isolate from 1 soil sample and used PCR for identification. The LSPQ obtained isolates from bronchoalveolar lavages and, in collaboration with Canada’s National Microbiology Laboratory, confirmed their identity by using the 16S sequencing method. Pulsed-field gel electrophoresis was used to investigate concordance of the outbreak strains and to compare the isolates’ patterns with those obtained from previous L. longbeachae isolates from Quebec. An adaptation of the full pulsed-field gel electrophoresis SfiI protocol developed for L. pneumophila (4) was also conducted by using AscI for L. longbeachae isolates.
Figure. Patterns of pulsed-field gel electrophoresis (PFGE) using AscI and SfiI enzymes for specimens from 2 occupational cases of Legionella longbeachae infection, a positive soil sample, and various other L. longbeachaestrains...
All soil samples were positive for Legionella spp., an expected outcome because these bacteria are ubiquitous in the environment. PCR and cultures conducted on the soil sample taken near the truck-unloading station were positive for L. longbeachae. By using the 2 enzymes (AscI and SfiI) protocol, laboratory findings showed that the strains from the 2 patients and from the positive soil sample were concordant (Figure), except for 1 difference, and were closely related, according to Tenover’s criteria (5).
Conclusions
L. longbeachae infections are rarely reported in Quebec. During 2003–2014, the LSPQ identified only 7 sporadic cases and no geographic clustering. In 2015, 2 severe L. longbeachae pneumonia cases occurred 1 month apart. The determination that the only common temporospatial exposure for the 2 patients was the workplace constitutes a strong epidemiologic link. Furthermore, L. longbeachae of the same genotype was isolated in the workplace soil samples. Although the diversity and distribution of L. longbeachae strains in Quebec soils are unknown, finding the same L. longbeachae genotype in the workplace soil suggests a causal link between the 2 case-patients and their workplace.
Unlike clusters of L. longbeachae described in the literature (6,7), these 2 patients did not come into contact with potting soils or compost during the exposure period. However, several sources of soil were found in their work environment. Although L. longbeachae usually is found in highly organic soil (2), the positive soil sample in this investigation came from poor soil. Until now, no Legionnaires’ disease case has been linked to L. longbeachae in this type of soil. Possibly, L. longbeachae traveled from the environment surrounding the plant or from soil trapped in trunks of wrecked cars. Also, soil analysis results might not reflect the conditions that prevailed during the exposure period.
This outbreak resolved spontaneously. The regional public health authority recommended preventive measures, such as handwashing, reinforced personal hygiene, avoidance of soil dumping from car trunks, and dust control.
The small number of cases in this outbreak and a general paucity of knowledge about L. longbeachae limited this investigation. The precise mechanism leading to infection has not yet been identified. Whereas hand-to-mouth contamination followed by microaspiration (8) seems the most probable route of exposure, dust inhalation cannot be ruled out. Early mobilization of experts and good collaboration with the implicated company facilitated the outbreak investigation.
These cases highlight the need to search for L. longbeachae in cases of severe pneumonia by performing appropriate cultures and to consider the risk for occupational exposure when soil is present. Environmental investigation appears useful to understand L. longbeachae transmission and ecology in Canada’s soils. Additional research is needed to improve understanding of sources of exposure, the pathogenesis of this species, and appropriate control measures.
Dr. Picard-Masson is a public health and preventive medicine specialist working with the environmental health team of the Montérégie Public Health Department in Quebec, Canada. Her research interests include occupational and environmental health.
Acknowledgment
We thank Pierre Chevalier, Benoit Lévesque, Denis Gauvin, and Jean Longtin from the Institut National de Santé Publique du Québec for their help in this investigation.
References
- Steinert M, Hentschel U, Hacker J. Legionella pneumophila: an aquatic microbe goes astray. FEMS Microbiol Rev. 2002;26:149–62. DOIPubMed
- Whiley H, Bentham R. Legionella longbeachae and legionellosis. Emerg Infect Dis. 2011;17:579–83. DOIPubMed
- Agence de la santé publique du Canada. Legionella pneumophila [in French]. Modified 2011 Apr 19 [cited 2015 Dec 1]. http://www.phac-aspc.gc.ca/lab-bio/res/psds-ftss/legionella-fra.php
- Lévesque S, Plante PL, Mendis N, Cantin P, Marchand G, Charest H, Genomic characterization of a large outbreak of Legionella pneumophilaserogroup 1 strains in Quebec City, 2012. PLoS One. 2014;9:e103852. DOIPubMed
- Tenover FC, Arbeit RD, Goering RV, Mickelsen PA, Murray BE, Persing DH, Interpreting chromosomal DNA restriction patterns produced by pulsed-field gel electrophoresis: criteria for bacterial strain typing. J Clin Microbiol. 1995;33:2233–9.PubMed
- Potts A, Donaghy M, Marley M, Othieno R, Stevenson J, Hyland J, Cluster of Legionnaires disease cases caused by Legionella longbeachae serogroup 1, Scotland, August to September 2013. Euro Surveill. 2013;18:20656.DOIPubMed
- Pravinkumar SJ, Edwards G, Lindsay D, Redmond S, Stirling J, House R, A cluster of Legionnaires’ disease caused by Legionella longbeachae linked to potting compost in Scotland, 2008–2009. Euro Surveill. 2010;15:19496.PubMed
- Steele TW. The ecology of Legionella longbeachae in Australia. Med J Aust. 1996;164:703–4.PubMed
Figure
Suggested citation for this article: Picard-Masson M, Lajoie É, Lord J, Lalancette C, Marchand G, Levac É, et al. Two related occupational cases of Legionella longbeachae infection, Quebec, Canada. Emerg Infect Dis. 2016 Jul [date cited]. http://dx.doi.org/10.3201/eid2207.161084.
1These authors were co–principal investigators.
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