Epidemiology and direct health care costs of hospitalised legionellosis in New Zealand, 2000-2020.

BACKGROUND: Legionellosis is a collective term used for disease caused by Legionella species which result in community and hospital acquired pneumonia worldwide. The aim of this analysis was to describe the epidemiology of legionellosis hospitalisations in Aotearoa New Zealand (NZ) over a 21-year period and quantify the health care costs. METHOD: This study combined national legionellosis notification and hospital discharge data that were linked via the National Health Index (NHI) to provide a more complete dataset of hospitalised cases. The direct cost of hospital care was estimated by multiplying the diagnosis-related group cost-weight by the national price and inflating to 2020/2021 values. RESULTS: There were 1479 records matched across notifications and discharge databases, including 990 with principal and 489 with additional diagnosis of legionellosis. Incidence rose to an average of 143 cases per annum for 2016-2020, a rate of 3·2/100,000. The median LOS was 6 days (IQR 4-13·5) with direct costs of $2·1 million per annum over that period. Rates were highest in those aged 65 years and above, male, and of European/Other ethnicity. Hospitalisations showed a peak in spring and summer. CONCLUSION: The rate of hospitalised legionellosis in New Zealand rose from 2000 to 2015, largely reflecting improved diagnosis. This preventable disease results in substantial health care costs. Greater efforts are needed to identify and control sources of exposure. Surveillance could be improved by routine integration of notification and hospital discharge data.

Legionellosis risk-an overview of Legionella spp. habitats in Europe.

An increase in the number of reports of legionellosis in the European Union and the European Economic Area have been recorded in recent years. The increase in cases is significant: from 6947 reports in 2015 to 11,298 in 2019. This is alarming as genus Legionella, which comprises a large group of bacteria inhabiting various aquatic systems, poses a serious threat to human health and life, since more than 20 species can cause legionellosis, with L. pneumophila being responsible for the majority of cases. The ability to colonize diverse ecosystems makes the eradication of these microorganisms difficult. A detailed understanding of the Legionella habitat may be helpful in the effective control of this pathogen. This paper provides an overview of Legionella environments in Europe: natural (lakes, groundwater, rivers, compost, soil) and anthropogenic (fountains, air humidifiers, water supply systems), and the role of Legionella spp. in nosocomial infections, which are potentially fatal for children, the elderly and immunocompromised patients.

Legionellosis after hematopoietic stem cell transplantation.

Limited data are available on legionellosis after hematopoietic stem cell transplant (HSCT). The aim of this study was to report the cases of legionellosis and to identify predictors of legionellosis, legionellosis-associated death, and non-relapse mortality (NRM). All cases of post-HSCT legionellosis from the EBMT registry were included and matched with controls in a 3:1 ratio for the analyses of risk factors. In the years 1995-2016, 80 cases from 52 centers in 14 countries were identified (mainly from France, Italy, and Spain). Median time from HSCT to legionellosis was 203 days (range, 0-4099); 19 (23.8%) patients developed early legionellosis (within-day +30 post-HSCT). Patients were mainly male (70%), after allogeneic HSCT (70%), with acute leukemia (27.5%), lymphoma (23.8%), or multiple myeloma (21.3%), and the median age of 46.6 (range, 7.2-68.2). Predictors of legionellosis were allogeneic HSCT (OR = 2.27, 95%CI:1.08-4.80, p = 0.03) and recent other infection (OR = 2.96, 95%CI:1.34-6.52, p = 0.007). Twenty-seven (33.8%) patients died due to legionellosis (44% after early legionellosis), NRM was 50%. Predictors of NRM were female sex (HR = 2.19, 95%CI:1.13-4.23, p = 0.02), early legionellosis (HR = 2.24, 95%CI:1.13-4.46, p = 0.02), and south-eastern geographical region (HR = 2.16, 95%CI:1.05-4.44, p = 0.036). In conclusion, legionellosis is a rare complication after HSCT, mainly allogeneic, occurring frequently within 30 days after HSCT and associated with high mortality.

[Legionella spp: An update]. / Actualités sur les infections à Legionella.

Legionella-related disease is caused by an intracellular bacteria mainly living in water. Contamination results from inhalation of Legionella sp containing aerosolized water. Main risk factors are tobacco, immunodeficiency, and advanced age. Antigenuria is the cornerstone of the diagnosis. Immunocompromised patients, more commonly infected with non pneumophilaLegionella, present negative antigenuria, and culture and PCR are essential for the diagnosis. Legionnaires' disease may be severe, especially in elderly and/or immunocompromised patients. Mortality rate varies from 10 % in the general population to 50 % in intensive care. Treatment is based on macrolides or fluoroquinolones. Antibiotic resistance is very rare.

[Perché la legionellosi è una tra le più temibili ICA].

La Legionellosi è una polmonite che può presentare un decorso variabile a seconda se i soggetti colpiti risiedono nel loro domicilio, sono ospiti di strutture recettive o sono ospedalizzati. In ambito ospedaliero, che annovera questa patologia tra le più pericolose Infezioni Correlate all'Assistenza (ICA), si registrano decisamente i casi più gravi e assai spesso letali. Gli errori nella Valutazione del Rischio e negli interventi di risanamento contribuiscono alla proliferazione all'interno delle condutture idriche di un temibile microrganismo che può essere eliminato o ridotto solo con un approccio multidisciplinare.

Community outbreak of legionellosis and an environmental investigation into a community water system.

During two legionellosis outbreak investigations, one at a geriatric centre and the other in high-rise housing for seniors, it was observed that additional cases of legionellosis occurred in nearby smaller residential settings. This apparent geographical cluster of legionellosis occurred in the same general area of a community water storage tank. No potential airborne sources in or near the area could be identified, but a community water system storage tank that was centrally located among case residences spurred an investigation of water-quality factors in the identified investigation area. Conditions conducive for Legionella growth, particularly low chlorine residuals, were found. The rate of legionellosis among residents aged ⩾50 years in the investigation areas (61·0 and 64·1/100 000) was eight times higher than in the rest of the service area (9·0/100 000) and almost 20 times higher than the statewide annual average incidence rate (3·2/100 000). A water mains flushing programme in the area was launched by the water utility, and water samples taken before and during flushing found L. pneumophila.

[Legionella infection--a neglected problem]. / Legionelové infekce - opomíjený problém.

UNLABELLED: Pathogenic species of the Legionella genus can cause respiratory diseases ranging in severity from benign Pontiac fever to life-threatening Legionnaires disease often characterized by severe pneumonia, high fever, and multiple organ involvement. Predisposing underlying conditions, such as immunosuppression, chronic lung disease, and malignancies and other variables such as smoking and higher age constitute high-risk factors. Legionalla has been isolated from natural aquatic habitats (freshwater streams and lakes, water reservoirs, etc.), artificial sources, and also from humid soil. These pathogens are distributed worldwide. Besides water reservoirs (surface and underground water, fresh and salt water), they occur in a wide range of technical devices and systems - water distribution systems, showers, pools, spa systems, perlators, foggy makers, irrigation systems with sprinklers, cooling towers, etc. About 20% of detected Legionella infections in Europe have been associated with travel history. Travel-associated cases present a particular difficulty in terms of identifying the source of infection and implementing remedial measures. KEYWORDS: Legionella pneumophila - Legionnaires disease - Pontiac fever - nosocomial infections.

Legionella spp. and legionellosis in southeastern Italy: disease epidemiology and environmental surveillance in community and health care facilities.

BACKGROUND: Following the publication of the Italian Guidelines for the control and prevention of legionellosis an environmental and clinical surveillance has been carried out in Southeastern Italy. The aim of the study is to identify the risk factors for the disease, so allowing better programming of the necessary prevention measures. METHODS: During the period January 2000 - December 2009 the environmental surveillance was carried out by water sampling of 129 health care facilities (73 public and 56 private hospitals) and 533 buildings within the community (63 private apartments, 305 hotels, 19 offices, 4 churches, 116 gyms, 3 swimming pools and 23 schools). Water sampling and microbiological analysis were carried out following the Italian Guidelines. From January 2005, all facilities were subject to risk analysis through the use of a standardized report; the results were classified as good (G), medium (M) and bad (B). As well, all the clinical surveillance forms for legionellosis, which must be compiled by physicians and sent to the Regional Centre for Epidemiology (OER), were analyzed. RESULTS: Legionella spp. was found in 102 (79.1%) health care facilities and in 238 (44.7%) community buildings. The percentages for the contamination levels < 1,000, 1,000-10,000, > 10,000 cfu/L were respectively 33.1%, 53.4% and 13.5% for samples from health care facilities and 33.5%, 43.3% and 23.2% for samples from the community. Both in hospital and community environments, Legionella pneumophila serogroup (L. pn sg) 2-14 was the most frequently isolate (respectively 54.8% and 40.8% of positive samples), followed by L. pn sg 1 (respectively 31.3% and 33%). The study showed a significant association between M or B score at the risk analysis and Legionella spp. positive microbiological test results (p < 0.001). From clinical surveillance, during the period January 2001 - August 2009, 97 cases of legionellosis were reported to the OER: 88 of community origin and 9 nosocomial. The most frequent symptoms were: fever (93.8%), cough (70.1%), dyspnea (58.8%), shivering (56.7%). Radiological evidence of pneumonia was reported in 68%. The laboratory diagnostic methods used were: urinary antigen (54.3%), single antibody titer (19.8%), only seroconversion (11.1%), other diagnostic methods (14.8%). CONCLUSIONS: Our experience suggests that risk analysis and environmental microbiological surveillance should be carried out more frequently to control the environmental spread of Legionella spp. Furthermore, the laboratory diagnosis of legionellosis cannot be excluded only on the basis of a single negative test: some patients were positive to only one of the diagnostic tests.

Legionnaires disease in cannabis smokers.

Tobacco smoking is a well-recognized risk factor for Legionnaires disease. However, it may be potentiated by cannabis use, as there is strong evidence that Δ(9)-tetrahydrocannabinol impairs immune functions in vitro and in vivo. We report herein two out of three cases of severe Legionnaires disease in three men with no overt comorbid illnesses, aged 38, 28, and 48 years, respectively. All of them were heavy cigarette and cannabis smokers.

[Legionella longbeachae pneumonia infection from home garden soil].

A 72-year-old critically ill and intubated man was transferred to our hospital, because of worsening pneumonia unresponsive to Cefazolin and Meropenem, from the hospital where he had been admitted 8 days before to start maintenance hemodialysis for chronic renal failure but had fever from admission. In a few days his critical condition rapidly subsided with the initiation of Ciprofloxacin and his sputum culture on GVPC medium indicated Legionellosis, which was afterwards identified as L. longbeachae by PCR and DNA-DNA hybridization. After recovery he said that he had been fond of gardening and had been gardening immediately before the initial admission. Moreover, several reports from Australia suggested inhalation of aerosolized potting soil as the route of L. longbeacachae infection; therefore, we examined the soil of his home garden and identified it. Thus, we present this case as the first of L. longbeachae pneumonia in Japan, proved to be infected via inhalation of aerosolized home garden soil.

Increased rainfall is associated with increased risk for legionellosis.

Legionnaires' disease (LD) is caused by Legionella species, most of which live in water. The Mid-Atlantic region experienced a sharp rise in LD in 2003 coinciding with a period of record-breaking rainfall. To investigate a possible relationship, we analysed the association between monthly legionellosis incidence and monthly rainfall totals from January 1990 to December 2003 in five Mid-Atlantic states. Using negative binomial model a 1-cm increase in rainfall was associated with a 2.6% (RR 1.026, 95% CI 1.012-1.040) increase in legionellosis incidence. The average monthly rainfall from May to September 1990-2002 was 10.4 cm compared to 15.7 cm from May to September 2003. This change in rainfall corresponds to an increased risk for legionellosis of approximately 14.6% (RR 1.146, 95% CI 1.067-1.231). Legionellosis incidence increased during periods of increased rainfall; identification of mechanisms that increase exposure and transmission of Legionella during rainfall might lead to opportunities for prevention.

Use of sequence-based typing for investigation of a case of nosocomial legionellosis.

A fatal case of nosocomial legionellosis in a low prevalence region (Calgary, Alberta, Canada) prompted investigation into the source of infection. Hospital water systems contaminated with Legionella pneumophila have been shown to pose a risk to compromised patients. Typing of an L. pneumophila serogroup 1 strain isolated from the patient using sequence-based typing (SBT) and amplified fragment length polymorphism (AFLP) analysis linked it to a persistent and widespread strain isolated from the hospital water system establishing a nosocomial mode of acquisition. Different SBT and AFLP patterns were determined for non-epidemiologically linked cases and isolates from different hospitals.

[Pathogenesis, diagnosis and therapy of Legionella infections]. / Pathogenese, Diagnostik und Therapie der Legionella-Infektion.

Legionella species are ubiquitous in aquatic environments. About 50 years ago they entered the engineered (technical) environment, i.e. warm water systems with zones of stagnation. Since that time they represent a hygienic problem. After transmission to humans via aerosols legionellae might cause Legionella pneumonia (legionnaires' disease) or influenza-like respiratory infections (Pontiac fever). Epidemiological data suggest that Legionella strains might differ substantially in their virulence properties. Although the molecular basis is not understood L. pneumophila serogroup 1 especially MAb 3/1-positive strains cause the majority of infections. The main virulence feature is the ability to multiply intracellularly. After uptake into macrophages legionellae multiply in a specialized vacuole and finally lyse their host cells. Several bacterial factors like surface components, secretion systems and iron uptake systems are involved in this process. Since the clinical picture of Legionella pneumonia does not allow differentiation from pneumoniae caused by other pathogens, microbiological diagnostic methods are needed to establish the diagnosis. Cultivation of legionellae from clinical specimens, detection of antigens and DNA in patients' samples and detection of antibodies in serum samples are suitable methods. However, none of the diagnostic tests presently available offers the desired quality with respect to sensitivity and specificity. Therefore, the standard technique is to use several diagnostic tests in parallel. Advantages and disadvantages of the diagnostic procedures are discussed. Therapeutic options for Legionella infections are newer macrolides like azithromycin and chinolones (ciprofloxacin, levofloxacin and moxifloxacin).

Outbreak of travel-related pontiac fever among hotel guests illustrating the need for better diagnostic tests.

BACKGROUND: Pontiac fever (PF), a legionellosis with influenza-like symptoms and high attack rates, is rarely reported. Travel-related outbreaks can elude detection because infected persons are often widely removed geographically from the transmission source before illness onset. Thirty-one persons staying at an Illinois hotel during August 9 to 11, 2002, reported influenza-like symptoms to local health departments within 24 to 48 hours of checkout. We investigated to identify the cause and source of illness to guide control measures. METHODS: Hotel water samples were collected for culture. A telephone questionnaire detailing illness symptoms and exposures was administered to all who were guests at the hotel from August 9 to 15 (n = 380). A case was defined as onset of fever, headache, and myalgia in a guest in the 14 days following the hotel stay. Patient sera were tested by hemagglutination assay for antibodies to Legionella species. RESULTS: Among 204 questionnaire respondents from 15 states and Canada, 50 met the case definition. Among persons exposed to the swimming pool/whirlpool spa area, 63% (47 of 75) became ill versus 3% (3 of 110) of unexposed persons (relative risk 23.0, 95% CI 7.4-71.1). Illness risk increased with increasing time exposed to the pool/spa. Approximately 95 to 115 bathers per day, two to three times above the usual number, used the spa during August 9 to 11. Three Legionella species, L. dumoffii, L. maceachernii, and L. micdadei, were isolated from spa filter backwash cultures. Two of 15 ill persons with acute- and convalescent-phase sera had a greater than fourfold rise in antibody titer to L. micdadei. CONCLUSIONS: PF was associated with exposure to a hotel pool/spa area. Heavy bather usage likely contributed to a decreased effectiveness of the disinfectant in the whirlpool spa, possibly promoting bacterial aerosolization. Linking case information from many states is essential in identifying and eliminating the source of disease transmission in travel-related outbreaks of PF. Clinicians should be aware of PF in the differential diagnosis of patients with influenza-like symptoms following recent travel, particularly with exposure to a communal-use whirlpool spa.

[Increased risk of infection with biological immunomodifying antirheumatic agents. Clear guidelines are necessary as shown by case reports]. / Okad risk för infektion med biologiska immunmodifierande antireumatika.

Several potent immunosuppressive drugs have become available in the new millennium for patients with rheumatologic diseases, Crohn's disease and other autoimmune disorders. Five patient cases from Växjö central hospital (uptake area 178 000 individuals) with Listeria meningitis, Pneumocystis jiroveci and tuberculosis pneumonia, Listeria sepsis, Legionella pneumonia and E coli sepsis are described. A doubled risk for infections has previously been observed for RA patients, as compared to healthy individuals. There is clearly an increased risk of tuberculosis (depending on the actual and historic environmental prevalence) for patients on TNF antagonists, and therefore tuberculosis screening is now mandatory before start of therapy. Since TNF has a central role in the immune defence, an increased risk of opportunistic infections like listeriosis. mycobacteriosis, and invasive fungal infections has been established. Eight hospitals in southern Sweden participate in a register for the use of TNF blockers in rheumatologic diseases (South Swedish Arthritis Treatment Group, SSATG). Guidelines for screening and treatment of latent and active tuberculosis, possible prophylactic antibiotic treatment for endocarditis and vaccination programs for patients on TNF antagonists are discussed.