Legionnaires' Disease Cases Research Articles

Severe bilateral pleuropneumonia caused by Legionella sainthelensi: a case report

BackgroundLegionella spp. are ubiquitous freshwater bacteria responsible for rare but potentially severe cases of Legionnaires’ disease (LD). Legionella sainthelensi is a non-pneumophila Legionella species that was first isolated in 1980 from water near Mt. St-Helens (USA). Although rare cases of LD caused by L. sainthelensi have been reported, very little data is available on this pathogen.Case presentationWe describe the first documented case of severe bilateral pleuropneumonia caused by L. sainthelensi. The patient was a 35-year-old woman with Sharp’s syndrome treated with long-term hydroxychloroquine and corticosteroids who was hospitalized for an infectious illness in a university hospital in Reunion Island (France). The patient’s clinical presentation was complicated at first (bilateral pneumonia, multiloculated pleural effusion, then bronchopleural fistula) but her clinical condition eventually improved with the reintroduction of macrolides (spiramycin) in intensive care unit. Etiological diagnosis was confirmed by PCR syndromic assay and culture on bronchoalveolar lavage.ConclusionsTo date, only 14 documented cases of L. sainthelensi infection have been described worldwide. This pathogen is difficult to identify because it is not or poorly detected by urinary antigen and molecular methods (like PCR syndromic assays that primarily target L. pneumophila and that have only recently been deployed in microbiology laboratories). Pneumonia caused by L. sainthelensi is likely underdiagnosed as a result. Clinicians should consider the possibility of non-pneumophila Legionella infection in patients with a compatible clinical presentation when microbiological diagnostic tools targeted L. pneumophila tested negative.

Extreme Precipitation and Legionnaires Disease Hospitalizations in Boston, Massachusetts from 2002-2012

BACKGROUND AND AIM: Legionnaires disease (LD) and Pontiac Fever are caused by exposure to Legionella spp. bacteria–environmental contaminants commonly found in water and soil. A milder disease, Pontiac Fever is typically self-limiting, and has a short incubation period of hours to days. The estimated incubation period for severe LD pneumonia is two–fourteen days and is the form of Legionellosis most likely to result in a hospital visit. Previous studies report LD associated with extreme weather conditions: higher humidity and increased precipitation. We conducted a retrospective study of air pollution, extreme precipitation, and LD-coded hospital visits in Boston, Massachusetts. METHODS: We analyzed weather and air pollution data: humidity, temperature, precipitation, ozone, and fine particulates (PM2.5) with LD ICD-9 code 482.84 hospital visits. Variables were assessed as continuous variables, at extremes, in different seasons, and at multiple LD case time lags. Using time-series analysis and negative binomial methods, final multivariable models included extreme precipitation events, temperature, and the occurrence of LD-related hospital visits. RESULTS:A total of 466 hospital visits were identified during 2002-2012. The selected model had the lowest AIC and included an autocorrelation term for LD case frequency from lag 1 to 7 days, mean temperature, and extreme precipitation (90th percentile). Extreme precipitation events were associated after 9 and 11 lag days with IRR of 1.54 (95% CI, 1.1379 – 2.0496) and 1.38 (95% CI, 1.0086 – 1.8610) respectively. We did not find an association with temperature, particulates or ozone, and humidity was excluded because of collinearity with precipitation (R = 0.39). CONCLUSIONS:Hospital visits for LD significantly increased at lag days nine and eleven occurred after extreme precipitation events. We did not find a significant association with air pollution. These findings agree with other reports of LD occurrence after wet weather. This abstract does not reflect EPA policy. KEYWORDS: Climate, Water quality, Infectious diseases

Atmospheric dispersion and transmission of Legionella from wastewater treatment plants: A 6-year case-control study.

An atmospheric dispersion model was used to generate nationwide exposure maps of aerosols from 776 WWTPs in the Netherlands. Municipal sewage treatment plants and industrial WWTPs were both included. Exposure of LD cases and controls at the residential address was compared, in a matched case-control design using a conditional logistic regression. Cases were notified LD cases with onset of disease in the period 2013-2018 in the Netherlands (n=1604). Aerosols dispersed over a large part of the Netherlands, but modelled concentrations are estimated to be elevated in close proximity to WWTPs. A statistically significant association was found between LD and the calculated annual average aerosol concentrations originating from WWTPs (odds-ratio: 1.32 (1.06-1.63)). This association remained significant when the two outbreak-related WWTPs were removed from the analysis (odds-ratio: 1.28 (1.03-1.58)). LD cases were more exposed to aerosols from WWTPs than controls. This indicates that exposure to aerosols dispersed from WWTPs caused Legionnaires Disease in residents living near WWTPs in the period 2013-2018. In order to investigate which characteristics of WWTPs are associated with an increased LD risk, the WWTP database should be updated and more data is needed on the presence and survival of aerosolized Legionella bacteria to improve the Legionella dispersion modelling. Furthermore, it is recommended to further investigate how aerosol dispersion of WWTPs can effectively be reduced in order to reduce the potential health risk.

Legionella pneumophila-Epidemiology and Characterization of Clinical Isolates, Slovenia, 2006-2020.

Legionella pneumophila is the causative agent of severe Legionnaires’ disease (LD). Although an increasing number of LD cases have been observed, published data from Slovenia are very limited and data on molecular epidemiology are even scarcer. The present retrospective study (2006–2020) reports the results of the microbiological diagnosis of LD, as well as the epidemiology and characterization of the Legionella clinical isolates. We tested urine samples from 15,540 patients with pneumonia symptoms for L. pneumophila infection by urine antigen test, of which 717 (4.6%) tested positive. Isolation of L. pneumophila was successfully performed from 88 clinical specimens, with 82 (93.2%) being identified as L. pneumophila sg 1 and six (6.8%) as L. pneumophila sg 2–14. Sequence-based typing (SBT) identified 33 different sequence types (STs), the most frequent being ST1 and ST23. Sequence type 1 mainly comprised isolates belonging to the Philadelphia subgroup, and ST23 mostly to Allentown/France. The standard SBT scheme, as well as Dresden phenotyping for L. pneumophila, presented a high diversity among isolates.

A Legionnaires' Disease Cluster in a Private Building in Italy.

Legionnaires’ disease (LD) is a severe pneumonia caused by bacteria belonging to the genus Legionella. This is a major public health concern and infections are steadily increasing worldwide. Several sources of infection have been identified, but they have not always been linked to human isolates by molecular match. The well-known Legionella contamination of private homes has rarely been associated with the acquisition of the disease, although some patients never left their homes during the incubation period. This study demonstrated by genomic matching between clinical and environmental Legionella isolates that the source of an LD cluster was a private building. Monoclonal antibodies and sequence-based typing were used to type the isolates, and the results clearly demonstrated the molecular relationship between the strains highlighting the risk of contracting LD at home. To contain this risk, the new European directive on the quality of water intended for human consumption has introduced for the first time Legionella as a microbiological parameter to be investigated in domestic water systems. This should lead to a greater attention to prevention and control measures for domestic Legionella contamination and, consequently, to a possible reduction in community acquired LD cases.

A community-acquired Legionnaires’ disease outbreak caused by Legionella pneumophila serogroup 2: an uncommon event, Italy, August to October 2018

In September 2018 in Brescia province, northern Italy, an outbreak of Legionnaires' disease (LD) caused by Legionella pneumophila serogroup 2 (Lp2) occurred. The 33 cases (two fatal) resided in seven municipalities along the Chiese river. All cases were negative by urinary antigen test (UAT) and most were diagnosed by real-time PCR and serology. In only three cases, respiratory sample cultures were positive, and Lp2 was identified and typed as sequence type (ST)1455. In another three cases, nested sequence-based typing was directly applied to respiratory samples, which provided allelic profiles highly similar to ST1455. An environmental investigation was undertaken immediately and water samples were collected from private homes, municipal water systems, cooling towers and the river. Overall, 533 environmental water samples were analysed and 34 were positive for Lp. Of these, only three samples, all collected from the Chiese river, were Lp2 ST1455. If and how the river water could have been aerosolised causing the LD cases remains unexplained. This outbreak, the first to our knowledge caused by Lp2, highlights the limits of UAT for LD diagnosis, underlining the importance of adopting multiple tests to ensure that serogroups other than serogroup 1, as well as other Legionella species, are identified.

Improvements to the Success of Outbreak Investigations of Legionnaires' Disease: 40 Years of Testing and Investigation in New York State.

ABSTRACTSince 1978, the New York State Department of Health’s public health laboratory, Wadsworth Center (WC), in collaboration with epidemiology and environmental partners, has been committed to providing comprehensive public health testing for Legionella in New York. Statewide, clinical case counts have been increasing over time, with the highest numbers identified in 2017 and 2018 (1,022 and 1,426, respectively). Over the course of more than 40 years, the WC Legionella testing program has continuously implemented improved testing methods. The methods utilized have transitioned from solely culture-based methods for organism recovery to development of a suite of reference testing services, including identification and characterization by PCR and pulsed-field gel electrophoresis (PFGE). In the last decade, whole-genome sequencing (WGS) has further refined the ability to link outbreak strains between clinical specimens and environmental samples. Here, we review Legionnaires’ disease outbreak investigations during this time period, including comprehensive testing of both clinical and environmental samples. Between 1978 and 2017, 60 outbreaks involving clinical and environmental isolates with matching PFGE patterns were detected in 49 facilities from the 157 investigations at 146 facilities. However, 97 investigations were not solved due to the lack of clinical or environmental isolates or PFGE matches. We found 69% of patient specimens from New York State (NYS) were outbreak associated, a much higher rate than observed in other published reports. The consistent application of new cutting-edge technologies and environmental regulations has resulted in successful investigations resulting in remediation efforts.IMPORTANCE Legionella, the causative agent of Legionnaires’ disease (LD), can cause severe respiratory illness. In 2018, there were nearly 10,000 cases of LD reported in the United States (https://www.cdc.gov/legionella/fastfacts.html; https://wonder.cdc.gov/nndss/static/2018/annual/2018-table2h.html), with actual incidence believed to be much higher. About 10% of patients with LD will die, and as high as 90% of patients diagnosed will be hospitalized. As Legionella is spread predominantly through engineered building water systems, identifying sources of outbreaks by assessing environmental sources is key to preventing further cases LD.

A Methodology for Classifying Root Causes of Outbreaks of Legionnaires' Disease: Deficiencies in Environmental Control and Water Management.

We piloted a methodology for collecting and interpreting root cause—or environmental deficiency (ED)—information from Legionnaires’ disease (LD) outbreak investigation reports. The methodology included a classification framework to assess common failures observed in the implementation of water management programs (WMPs). We reviewed reports from fourteen CDC-led investigations between 1 January 2015 and 21 June 2019 to identify EDs associated with outbreaks of LD. We developed an abstraction guide to standardize data collection from outbreak reports and define relevant parameters. We categorized each ED according to three criteria: ED type, WMP-deficiency type, and source of deficiency. We calculated the prevalence of EDs among facilities and explored differences between facilities with and without WMPs. A majority of EDs identified (81%) were classified as process failures. Facilities with WMPs (n = 8) had lower prevalence of EDs attributed to plumbed devices (9.1%) and infrastructure design (0%) than facilities without WMPs (n = 6; 33.3% and 24.2%, respectively). About three quarters (72%) of LD cases and 81% of the fatalities in our sample originated at facilities without a WMP. This report highlights the importance of WMPs in preventing and mitigating outbreaks of LD. Building water system process management is a primary obstacle toward limiting the root causes of LD outbreaks. Greater emphasis on the documentation, verification, validation, and continuous program review steps will be important in maximizing the effectiveness of WMPs.

Travel-associated cases of Legionnaires’ disease in the United States, 2015–2016

BackgroundRecent travel is associated with ~20% of reported Legionnaires’ disease (LD) cases worldwide. MethodsWe analyzed LD cases reported to the Centers for Disease Control and Prevention (CDC) during 2015–2016. Travel-associated cases met case criteria for confirmed LD in someone who spent ≥1 night away from home during the 10 days before symptom onset. Most analyses were limited to travel-associated, public accommodation stay (TAPAS) cases. We used reported travel dates to estimate the number of TAPAS cases acquired during travel. ResultsOf 12,200 LD cases reported among U.S. residents, 12.3% were travel-associated; 8.7% were TAPAS. Median patient age for TAPAS cases was 61 years; 64.4% were male; 67.3% were white; 77.9% were non-Hispanic; 96.1% were hospitalized; 4.5% died. Among 887 TAPAS cases involving U.S. destinations, an estimated 29.8% were acquired during travel; 4.28 TAPAS cases were reported, and an estimated 1.10 TAPAS cases were acquired during travel, per 10,000,000 hotel room nights booked. Sixty-eight U.S. TAPAS clusters were detected. ConclusionsWhile acquisition during travel accounted for a relatively small proportion of all LD cases, clusters of TAPAS cases were frequently detected. Prompt notification of these cases to CDC facilitates cluster detection and expedites intervention.

Legionnaires' Disease on the Rise in Switzerland: A Denominator-Based Analysis of National Diagnostic Data, 2007-2016.

The risk of falling ill with Legionnaires’ disease (LD) is suggested to increase, but the global burden of disease is unknown due to a lack of appropriate diagnosis and surveillance systems. In Switzerland, the number of LD cases, captured by the National Notification System for Infectious Diseases, has more than doubled since 2008. This study aims to investigate this increase, contextualizing disease surveillance data with denominator data, which is not routinely available, i.e., the number of tests performed for Legionella spp. We collected the testing data for Legionella spp. of 14 Swiss diagnostic laboratories and calculated the positivity, defined as the proportion of the number of positive tests to the number of tests performed. The number of positive tests increased proportionally to the number of tests performed; hence, the positivity remained stable. However, the cause of the increase in test volume is unclear and has a large impact on the interpretation of the positivity curve. Further, the test outcome was found to be dependent on regional determinants, and the diagnostic method applied. The lack of understanding if and at which stage LD is considered in current case management of pneumonia patients limits the interpretation of observed heterogeneities in incidence or underestimation of LD in Switzerland. The absence of (or non-adherence to) existing guidelines and the heterogeneity in diagnostic testing hampers the comparison of data in the Swiss public health context. Therefore, diagnostic procedures should be harmonised across Switzerland and adherence to national LD management guidelines supported.

Legionnaires' Disease in Pediatric Patients, Control Measures and 5-Year Follow-up.

Legionnaires' disease (LD) occurs predominantly in adults and elderly people. Its incidence in Europe has been increasing in recent years. It is rare in younger age groups and prone to be reported as healthcare-associated infection with a higher risk of fatal outcome. Hospital-acquired LD is mostly associated with a colonized hospital water system. We describe 5 LD cases in a children's hospital in Slovakia, subsequent environmental investigation, control measures, and 5-year monitoring of Legionella colonization in hospital's water system. In 2014-2019, we tested clinical specimens from 75 hospitalized patients. Respiratory samples were cultured for Legionella, patient's urine was tested for Legionella urinary antigens, and the microagglutination test was used for serologic testing. Samples of water were collected in 2015-2019 and processed according ISO11731. We identified 5 Legionella infections in 2014-2015. Median age of patients was 15 years. All were high-risk patients hospitalized for their underlying diseases. All patients required admission to intensive care unit, and artificial ventilation due to general deterioration and respiratory failure. Legionella pneumophila was isolated from 72% of water samples. Chlorine dioxide dosing into water system above 0.3 ppm caused significant decrease of Legionella concentration in water samples. Samples taken from outlets with antimicrobial filter installed were legionellae-negative. Control measures led to decreased risk of infection, but not to eradication of Legionellae. It is necessary to extend the diagnostics for Legionella infection in hospitalized children with pneumonia, especially in hospitals with colonized water system.

Large community-acquired Legionnaires' disease outbreak caused by Legionella pneumophila serogroup 1, Italy, July to August 2018.

In July 2018, a large outbreak of Legionnaires’ disease (LD) caused by Legionella pneumophila serogroup 1 (Lp1) occurred in Bresso, Italy. Fifty-two cases were diagnosed, including five deaths. We performed an epidemiological investigation and prepared a map of the places cases visited during the incubation period. All sites identified as potential sources were investigated and sampled. Association between heavy rainfall and LD cases was evaluated in a case-crossover study. We also performed a case–control study and an aerosol dispersion investigation model. Lp1 was isolated from 22 of 598 analysed water samples; four clinical isolates were typed using monoclonal antibodies and sequence-based typing. Four Lp1 human strains were ST23, of which two were Philadelphia and two were France-Allentown subgroup. Lp1 ST23 France-Allentown was isolated only from a public fountain. In the case-crossover study, extreme precipitation 5–6 days before symptom onset was associated with increased LD risk. The aerosol dispersion model showed that the fountain matched the case distribution best. The case–control study demonstrated a significant eightfold increase in risk for cases residing near the public fountain. The three studies and the matching of clinical and environmental Lp1 strains identified the fountain as the source responsible for the epidemic.

Differential Seasonality of Legionnaires' Disease by Exposure Category.

Legionnaires’ disease (LD) shows a seasonal pattern with most cases occurring in summer. We investigate if seasonality can be observed for all three exposure categories (community-acquired (CALD), travel-associated (TALD) and healthcare-associated (HCA)). Methods: LD cases (2005–2015) were classified by exposure categories and we calculated the relative case ratio for each month from February to December using January as reference. The TALD relative case ratio was compared with flight frequencies. Results: Overall case numbers in Germany (N = 7351) peaked in August. CALD had a curve similar to all cases. TALD displayed a bimodal curve with peaks in June/July and October. The latter was attributable to LD cases aged 60+. The relative case ratio of TALD surpassed clearly that of CALD. The curve was similar to that of the relative flight frequencies, but was shifted by about one month. HCA showed no apparent seasonality. Conclusions: Although the overall seasonality in LD is heavily influenced by CALD, seasonal differences are more pronounced for TALD which may reflect travel behavior. The bimodal pattern of TALD is attributable to the curve among those aged 60+ and may reflect their preference to travel outside school holiday periods. Heightened vigilance for HCA cases is necessary throughout the entire year.

Legionnaires' Disease Cases at a Large Community Hospital-Common and Underdiagnosed.

Legionnaires’ disease (LD) is a severe pneumonia with a mortality rate of about 10%. The illness remains largely underdiagnosed with outbreaks occurring with alarming incidence. In this study, we assessed the frequency of Legionnaires’ disease among pneumonia cases treated at a large community hospital over a summer season. We invited all admitted patients diagnosed with pneumonia, able to provide a urine sample for an antigen test, presenting from May to October 2018, to enroll in our study; 35 patients were tested for the presence of Legionella. Out of 33 patients tested, 9 (28%) were positive for Legionella. Three sets of the 9 Legionella cases exhibited spatiotemporal clustering indicative of LD outbreaks. Only one of the 9 Legionella UAT-positive patients presented a sporadic case of LD. The number of pneumonia cases in our community confirmed to be LD was strikingly high (28%), compared to other survey studies that report between 3.7% and 14%. These results are consistent with previous knowledge that LD is underdiagnosed and support that routine testing should be considered for all possible LD cases, particularly in the summer months. Such testing is likely to prevent further cases of community acquired LD.

1606. Legionellosis Cluster Associated with Direct and Indirect Hot Tub Exposure—West Virginia, 2018

BackgroundIn October 2018, the West Virginia Bureau for Public Health (BPH) notified CDC of one Legionella urinary antigen test (UAT)-positive case of Legionnaires’ disease (LD) in a worker at a racetrack facility. Following investigation by BPH and the county health department, five additional LD cases were identified among facility workers within a one-month period. Our objective was to determine the extent of the outbreak and identify potential sources of exposure.MethodsWe interviewed the previously identified patients and conducted case-finding among racetrack workers. Our case definitions included confirmed LD (pneumonia with a positive UAT), suspected LD (pneumonia without a UAT completed), and Pontiac fever (PF) (self-limited, nonspecific flu-like symptoms) among employees with exposure to the facility within 14 days prior to symptom onset. We conducted an environmental assessment of the facility and the surrounding area for sources of potential Legionella exposure.ResultsWe identified 17 cases (71% in men, 35% in current smokers, median age 55 years): six confirmed LD, four suspected LD, and seven suspected PF cases. Our environmental assessment revealed a poorly maintained hot tub in the first floor jockey area. All samples collected from the hot tub (which was chlorinated before our arrival) tested negative for Legionella. Two employees with confirmed LD (33%), three with suspected LD (75%), and six with suspected PF (86%) had direct exposure to the hot tub or adjacent hallway; the remaining six were exposed only to a second floor office suite. Further investigation identified deficiencies in the facility’s ventilation systems and a crack in the floor between the hot tub and office areas. These factors created a pathway for Legionella-containing aerosols from the hot tub to pass into the second floor office space and air-handling unit for recirculation to occupied areas.ConclusionOur investigation suggests that both direct and indirect exposure to a Legionella reservoir can cause illness. This finding supports analysis of ventilation systems and airflow dynamics in future LD outbreak investigations. Clinicians should consider LD in pneumonia patients with direct or indirect exposure to suspected Legionella sources to ensure appropriate testing and treatment.Disclosures All authors: No reported disclosures.

A real-time PCR for specific detection of the Legionella pneumophila serogroup 1 ST1 complex

ObjectiveLegionella pneumophila serogroup 1 (Lp1) sequence type (ST) 1 is globally widespread in the environment and accounts for a significant proportion of Legionella infections, including nosocomial Legionnaires' disease (LD). This study aimed to design a sensitive and specific detection method for Lp ST1 that will underpin epidemiological investigations and risk assessment. MethodsA total of 628 Lp genomes (126 ST1s) were analyzed by comparative genomics. Interrogation of more than 900 accessory genes revealed seven candidate targets for specific ST1 detection and specific primers and hydrolysis probes were designed and evaluated. The analytical sensitivity and specificity of the seven primer and probe sets were evaluated on serially diluted DNA extracted from the reference strain CIP107629 and via qPCR applied on 200 characterized isolates. The diagnostic performance of the assay was evaluated on 142 culture-proven clinical samples from LD cases and a real-life investigation of a case cluster. ResultsOf seven qPCR assays that underwent analytical validation, one PCR target (lpp1868) showed higher sensitivity and specificity for ST1 and ST1-like strains. The diagnostic performance of the assay using respiratory samples corresponded to a sensitivity of 95% (19/20) (95% CI (75.1–99.9)) and specificity of 100% (122/122) (95% CI (97–100)). The ST1 PCR assay could link two out of three culture-negative hospitalized LD cases to ST1 during a real-time investigation. ConclusionUsing whole genome sequencing (WGS) data, we developed and validated a sensitive and specific qPCR assay for the detection of Lp1 belonging to the ST1 clonal complex by amplification of the lpp1868 gene. The ST1 qPCR is expected to deliver an added value for Lp control and prevention, in conjunction with other recently developed molecular assays.

Estimating the True Burden of Legionnaires' Disease.

Over the past decade, the reported incidence of Legionnaires' disease (LD) in the northeastern United States has increased, reaching 1-3 cases per 100,000 population. There is reason to suspect that this is an underestimate of the true burden, since LD cases may be underdiagnosed. In this analysis of pneumonia and influenza (P&I) hospitalizations, we estimated the percentages of cases due to Legionella, influenza, and respiratory syncytial virus (RSV) by age group. We fitted mixed-effects models to estimate attributable percents using weekly time series data on P&I hospitalizations in Connecticut from 2000 to 2014. Model-fitted values were used to calculate estimates of numbers of P&I hospitalizations attributable to Legionella (and influenza and RSV) by age group, season, and year. Our models estimated that 1.9%, 8.8%, and 5.1% of total (all-ages) inpatient P&I hospitalizations could be attributed to Legionella, influenza, and RSV, respectively. Only 10.6% of total predicted LD cases had been clinically diagnosed as LD during the study period. The observed incidence rate of 1.2 cases per 100,000 population was substantially lower than our estimated rate of 11.6 cases per 100,000 population. Our estimates of numbers of P&I hospitalizations attributable to Legionella are comparable to those provided by etiological studies of community-acquired pneumonia and emphasize the potential for underdiagnosis of LD in clinical settings.

Cluster of Legionnaires' Disease in an Italian Prison.

Background: Legionella pneumophila (Lp) is the most common etiologic agent causing Legionnaires’ Disease (LD). Water systems offer the best growth conditions for Lp and support its spread by producing aerosols. From 2015 to 2017, the Regional Reference Laboratory of Clinical and Environmental Surveillance of Legionellosis of Palermo monitored the presence of Lp in nine prisons in Western Sicily. During this investigation, we compared Lp isolates from environmental samples in a prison located in Palermo with isolates from two prisoners in the same prison. Methods: We collected 93 water samples from nine Sicilian prisons and the bronchoalveolar lavages (BALs) of two prisoners considered cases of LD. These samples were processed following the procedures described in the Italian Guidelines for the Prevention and Control of Legionellosis of 2015. Then, genotyping was performed on 19 Lp colonies (17 from water samples and 2 from clinical samples) using the Sequence-Based Typing (SBT) method, according to European Study Group for Legionella Infections (ESGLI) protocols. Results: Lp serogroup (sg) 6 was the most prevalent serogroup isolated from the prisons analyzed (40%), followed by Lp sg 1 (16%). Most of all, in four penitentiary institutions, we detected a high concentration of Lp >104 Colony Forming Unit/Liter (CFU/L). The environmental molecular investigation found the following Sequence Types (STs) in Lp sg 6: ST 93, ST 292, ST 461, ST 728, ST 1317 and ST 1362, while most of the isolates in sg 1 belonged to ST 1. We also found a new ST that has since been assigned the number 2451 in the ESGLI-SBT database. From the several Lp sg 1 colonies isolated from the two BALs, we identified ST 2451. Conclusions: In this article, we described the results obtained from environmental and epidemiological investigations of Lp isolated from prisons in Western Sicily. Furthermore, we reported the first cluster of Legionnaires’ in an Italian prison and the molecular typing of Lp sg 1 from one prison’s water system and two BALs, identified the source of the contamination, and discovered a new ST.

Project Development to Address Knowledge Gaps Identified in Long Term Care Related to Water Management Programs and Legionnaires’ Disease

BACKGROUND Legionnaires’ Disease (LD) is a growing concern in the United States. The number of LD cases has increased almost 4.5?times from 2000-2015. Most outbreaks have occurred in long term care (LTC), hospital and hotel settings. The Centers for Medicare and Medicaid Services, released a memo in 2017, which included requirements for LTC facilities to reduce Legionella risk in water systems to help prevent LD cases and outbreaks. However, limited tools and time are available to long term care facilities to meet requirements. A state health department received grant funding to create a video series to help LTC facilities implement and maintain water management programs (WMP). METHODS Key stakeholders were identified and interviewed. Key stakeholders were representatives from LTC facilities- infection preventionists (IP), administrators, and maintenance staff, local public health, state government representatives including an officer overseeing LTC facility surveyors, quality improvement organizations, and presidents of local LTC associations. WMPs were reviewed for 3 LTC facilities. An informal survey of LTC IPs was conducted at a local infection control conference, where participants were invited to write down questions related to LD and WMP, and what would be the most useful tool or activity to assist with implementation of a WMPs in their facility. RESULTS Key stakeholder (n=14) one-on-one interviews were completed. In each interview (n=12) knowledge gaps related to WMP requirements, implementation, and maintenance were mentioned. These gaps were found among LTC IPs, administration, maintenance, and surveyor staff. Knowledge gaps were also found related to what LD is, who is at risk, signs and symptoms and when to test for it. CONCLUSIONS There is a knowledge deficit in LTC facilities related to WMPs and LD. The series of videos created will need to address all steps of WMP creation and LD information to increase LTC staff knowledge, especially among IPs and maintenance.

Improvement of Legionnaires' disease diagnosis using real-time PCR assay: a retrospective analysis, Italy, 2010 to 2015.

AimTo evaluate real-time PCR as a diagnostic method for Legionnaires’ disease (LD). Detection of Legionella DNA is among the laboratory criteria of a probable LD case, according to the European Centre for Disease Prevention and Control, although the utility and advantages, as compared to culture, are widely recognised.MethodsTwo independent laboratories, one using an in-house and the other a commercial real-time PCR assay, analysed 354 respiratory samples from 311 patients hospitalised with pneumonia between 2010–15. The real-time PCR reliability was compared with that of culture and urinary antigen tests (UAT). Concordance, specificity, sensitivity and positive and negative predictive values (PPV and NPV, respectively) were calculated.ResultsOverall PCR detected eight additional LD cases, six of which were due to Legionella pneumophila (Lp) non-serogroup 1. The two real-time PCR assays were concordant in 99.4% of the samples. Considering in-house real-time PCR as the reference method, specificity of culture and UAT was 100% and 97.9% (95% CI: 96.2–99.6), while the sensitivity was 63.6% (95%CI: 58.6–68.6) and 77.8% (95% CI: 72.9–82.7). PPV and NPV for culture were 100% and 93.7% (95% CI: 91.2-96.3). PPV and NPV for UAT were 87.5% (95% CI: 83.6-91.4) and 95.8% (95% CI: 93.5-98.2).ConclusionRegardless of the real-time PCR assay used, it was possible to diagnose LD cases with higher sensitivity than using culture or UAT. These data encourage the adoption of PCR as routine laboratory testing to diagnose LD and such methods should be eligible to define a confirmed LD case.