Etiology and Prognosis of Pneumonia in Patients with Solid Tumors: A Prospective Cohort of Hospitalized Cases.

BACKGROUND: Data on the incidence, etiology, and prognosis of non-ventilator-associated pneumonia in hospitalized patients with solid tumors are scarce. We aimed to study the characteristics of non-ventilator-associated pneumonia in hospitalized patients with solid tumors. MATERIALS AND METHODS: This was a prospective noninterventional cohort study of pneumonia in patients hospitalized in an oncology ward in a tertiary teaching hospital. Pneumonia was defined according to the American Thoracic Society criteria. Patients were followed for 1 month after diagnosis or until discharge. Survivors were compared with nonsurvivors. RESULTS: A total of 132 episodes of pneumonia were diagnosed over 1 year (9.8% of admissions to the oncology ward). They were health care-related (67.4%) or hospital-acquired pneumonia (31.8%). Lung cancer was the most common malignancy. An etiology was established in 48/132 episodes (36.4%). Knowing the etiology led to changes in antimicrobial therapy in 58.3%. Subsequent intensive care unit admission was required in 10.6% and was linked to inappropriate empirical therapy. Ten-day mortality was 24.2% and was significantly associated with hypoxia (odds ratio [OR], 2.1). Thirty-day mortality was 46.2%. The independent risk factors for 30-day mortality were hypoxia (OR, 3.3), hospital acquisition (OR, 3.1), and a performance status >1 (OR, 2.6). Only 40% of patients who died within 30 days were terminally ill. CONCLUSION: Pneumonia is a highly prevalent condition in hospitalized patients with solid tumors, even with nonterminal disease. Etiology is diverse, and poor outcome is linked to inappropriate empirical therapy. Efforts to get the empirical therapy right and reach an etiological diagnosis to subsequently de-escalate are warranted. IMPLICATIONS FOR PRACTICE: The present study shows that pneumonia is a prevalent infectious complication in patients admitted to oncology wards, with a very high mortality, even in non-terminally ill patients. Etiology is diverse, and etiological diagnosis is reached in fewer than 40% of cases in nonintubated patients. Intensive care unit admission, a marker of poor outcome, is associated with inappropriate empirical therapy. These results suggest that, to improve prognosis, a more precise and appropriate antimicrobial empirical therapy for pneumonia in patients with solid tumors is necessary, together with an effort to reach an etiological diagnosis to facilitate subsequent de-escalation.

Intervention to reduce the incidence of non-ventilator-associated hospital-acquired pneumonia: A pilot study.

BACKGROUND: Our aim was to evaluate the effectiveness of an intervention to reduce the incidence of non-ventilator-associated hospital-acquired pneumonia (NV-HAP) and determine compliance with preventive measures. METHODS: This was a quasi-experimental before-after study involving patients in the 53-bed Internal Medicine ward in a university hospital in Spain. The preventive measures included hand hygiene, dysphagia detection, head-of-bed elevation, withdrawal of sedatives in the event of confusion, oral care, and sterile or bottled water use. A prospective post-intervention study of the incidence of NV-HAP was carried out from February 2017 to January 2018 and compared with baseline incidence (May 2014 to April 2015). Compliance with preventive measures was analyzed with 3-point-prevalence studies (December 2015, October 2016, and June 2017). RESULTS: The rate of NV-HAP decreased from 0.45 cases (95% confidence interval 0.24-0.77) in the pre-intervention period to 0.18 cases per 1,000 patient-days (95% confidence interval 0.07-0.39) in the post-intervention period (P = .07). Compliance with most preventive measures improved after intervention and remained stable over time. CONCLUSIONS: The strategy improved the adherence to most of the preventive measures, with a decrease in the incidence of NV-HAP. Efforts to enhance adherence to such fundamental preventive measures are critical to lowering the incidence of NV-HAP.

Methicillin-resistant and methicillin-sensitive Staphylococcus aureus in pork industry workers, Catalonia, Spain.

Background: Methicillin-resistant S. aureus (MRSA) especially ST398, is a zoonotic agent. This study aimed to determine the prevalence of methicillin-susceptible S. aureus (MSSA) and MRSA among workers in the pork production chain. Methods: 659 workers associated with 123 pig farms, livestock transporters, one pig slaughterhouse, pork transporters and 23 pork butcheries were studied for S. aureus recovery, and all isolates were characterized (antibiotic resistance, MLST and spa-typing). Results: The prevalence of S. aureus was 35.5%, 75.6% of isolates being MRSA. The prevalence of MRSA was 68.7% (149/217) among pig farm, 33.9% (19/56) livestock transporters, 2.9% (9/306) slaughterhouse, 0% in pork transporters (0/36) and butchery workers (0/44). Of the 234 S. aureus-positive workers, 100% (149/149) of pig farm workers, 82.6% (19/23) of livestock transporters, and 16.4% (9/55) of slaughterhouse workers carried MRSA isolates (p < 0.001). Of the workers who had contact with live swine, 61.8% (178/288) were S. aureus-positive, MRSA being detected in 96.1% of cases (p < 0.001). The most frequent lineage among MRSA were: ST398 (97.7%; 173/177) and ST1 (1.7%; 3/177); and among MSSA were ST30 (19.2%; 11/57) and ST5 (10.5%; 6/57). The most frequent spa-types among MRSA were t011 (93.8%, 166/177) and t1451 (2.25%, 4/177), and among MSSA: t084 (10.5%, 6/57) and t021 (7.0%, 4/57). All MRSA isolates showed resistance to tetracycline, 92.7% to clindamycin, 81.9% to erythromycin and 40.1% to cotrimoxazole. Conclusions: Pig industry workers having occupational contact with live animals present a high risk of colonization of MRSA, especially by MRSA-ST398. Prevention measures should be intensified in any employment sector involving live animals.

Cloxacillin plus fosfomycin versus cloxacillin alone for methicillin-susceptible Staphylococcus aureus bacteremia: a randomized trial.

Treatment failure occurs in about 25% of patients with methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia. We assessed whether cloxacillin plus fosfomycin achieves better treatment success than cloxacillin alone in hospitalized adults with MSSA bacteremia. We conducted a multicenter, open-label, phase III-IV superiority randomized clinical trial. We randomly assigned patients (1:1) to receive 2 g of intravenous cloxacillin alone every 4 h or with 3 g of intravenous fosfomycin every 6 h for the initial 7 days. The primary endpoint was treatment success at day 7, a composite endpoint with the following criteria: patient alive, stable or with improved quick Sequential Organ Failure Assessment score, afebrile and with negative blood cultures for MSSA, adjudicated by an independent committee blinded to treatment allocation. We randomized 215 patients, of whom 105 received cloxacillin plus fosfomycin and 110 received cloxacillin alone. We analyzed the primary endpoint with the intention-to-treat approach in 214 patients who received at least 1 day of treatment. Treatment success at day 7 after randomization was achieved in 83 (79.8%) of 104 patients receiving combination treatment versus 82 (74.5%) of 110 patients receiving monotherapy (risk difference 5.3%; 95% confidence interval (CI), -5.95-16.48). Secondary endpoints, including mortality and adverse events, were similar in the two groups except for persistent bacteremia at day 3, which was less common in the combination arm. In a prespecified interim analysis, the independent committee recommended stopping recruitment for futility prior to meeting the planned randomization of 366 patients. Cloxacillin plus fosfomycin did not achieve better treatment success at day 7 of therapy than cloxacillin alone in MSSA bacteremia. Further trials should consider the intrinsic heterogeneity of the infection by using a more personalized approach. ClinicalTrials.gov registration: NCT03959345 .

Correlation between Clinical and Immunological Variables and Humoral Response to SARS-CoV-2 Vaccination in Adult Patients with Antibody Deficiency Disorders.

BACKGROUND: Prophylactic vaccination has proven to be the most effective strategy to fight the COVID-19 pandemic. METHODS: This was a prospective observational cohort study involving 30 predominantly antibody deficiency disorders (ADD)-afflicted adult patients on immunoglobulin replacement therapy vaccinated with three doses of the mRNA-1273 COVID-19 vaccine, and 10 healthy controls. Anti-RBD IgG antibodies were determined in plasma samples collected just before the first dose of mRNA-based COVID-19 vaccine and on weeks 4, 8, 24, and 28 following the first vaccination. Patients were categorized based on the levels of anti-RBD antibodies determined on w8 as non-, low-, and responders. Chi-square and Kruskal-Wallis tests were used to see if any variables correlated with humoral response levels. Any adverse effects of the mRNA-based vaccine were also noted. RESULTS: The COVID-19 vaccine was safe and well-tolerated. The humoral response elicited at w8 after vaccination depended on the type of ADD, the type of immunoglobulin deficiency, the presence of granulomatous lymphocytic interstitial lung disease, recent use of immunosuppressive drugs, and the switched memory B cells counts. The third vaccine dose boosted humoral response in previous responders to second dose but seldom in non-responders. CONCLUSIONS: The humoral response of patients with predominant ADD depends mostly on the type of immunodeficiency and on the frequency of B and T cell populations.

Kinetics of immune responses elicited after three mRNA COVID-19 vaccine doses in predominantly antibody-deficient individuals.

Mass vaccination campaigns reduced COVID-19 incidence and severity. Here, we evaluated the immune responses developed in SARS-CoV-2-uninfected patients with predominantly antibody-deficiencies (PAD) after three mRNA-1273 vaccine doses. PAD patients were classified based on their immunodeficiency: unclassified primary antibody-deficiency (unPAD, n = 9), common variable immunodeficiency (CVID, n = 12), combined immunodeficiency (CID, n = 1), and thymoma with immunodeficiency (TID, n = 1). unPAD patients and healthy controls (HCs, n = 10) developed similar vaccine-induced humoral responses after two doses. However, CVID patients showed reduced binding and neutralizing titers compared to HCs. Of interest, these PAD groups showed lower levels of Spike-specific IFN-γ-producing cells. CVID individuals also presented diminished CD8+T cells. CID and TID patients developed cellular but not humoral responses. Although the third vaccine dose boosted humoral responses in most PAD patients, it had limited effect on expanding cellular immunity. Vaccine-induced immune responses in PAD individuals are heterogeneous, and should be immunomonitored to define a personalized therapeutic strategies.

[Diversity of Legionella pneumophila in cooling towers: coculture kinetics and virulence studies]. / Diversidad de subtipos de Legionella pneumophila en torres de refrigeración: estudios de cinética de crecimiento y virulencia.

BACKGROUND: Legionella pneumophila (L. pneumophila) was isolated from three cooling towers involved in three community outbreaks of Legionnaires disease. Each cooling tower had two different chromosomal DNA subtypes. However, only one matched identically to the clinical strains. To try to understand why only one of the environmental strains caused clinical cases we investigated the intrinsic virulence of these strains. METHODS: We selected six strains of L. pneumophila sg.1: two strains (A1 and B1) from cooling tower 1, two strains (A2 and B2) from tower 2 and two strains (A3 and B3) from tower 3. One of the two subtypes (A) exhibited the same chromosomal DNA subtype as the strains isolated from the patients in each outbreak and the other exhibited a different subtype. The replication within macrophages, the presence of lipopolysaccharide epitope recognized by MAb 3/1 and the growth kinetics in BCYE broth were investigated. Isolates were typed by pulsed field electrophoresis. RESULTS: The A strains did not have a higher virulence level, but were able to grow and survive better than strains B in BCYE broth. CONCLUSIONS: These results suggest that the strains better adapted to the environment will manage to displace the others and will be able to spread and infect humans. The adaptation to the environmental conditions could play an important role in the pathogenesis of the strains.

Long-Term Use of Tedizolid in Osteoarticular Infections: Benefits among Oxazolidinone Drugs.

BACKGROUND: To evaluate the efficacy and safety of long-term use of tedizolid in osteoarticular infections. METHODS: Multicentric retrospective study (January 2017-March 2019) of osteoarticular infection cases treated with tedizolid. Failure: clinical worsening despite antibiotic treatment or the need of suppressive treatment. RESULTS: Cases (n = 51; 59% women, mean age of 65 years) included osteoarthritis (n = 27, 53%), prosthetic joint infection (n = 17, 33.3%), and diabetic foot infections (n = 9, 18%); where, 59% were orthopedic device-related. Most frequent isolates were Staphylococcus spp. (65%, n = 47; S. aureus, 48%). Reasons for choosing tedizolid were potential drug-drug interaction (63%) and cytopenia (55%); median treatment duration was 29 days (interquartile range -IQR- 15-44), 24% received rifampicin (600 mg once daily) concomitantly, and adverse events were scarce (n = 3). Hemoglobin and platelet count stayed stable throughout treatment (from 108.6 g/L to 116.3 g/L, p = 0.079; and 240 × 109/L to 239 × 109/L, p = 0.942, respectively), also in the subgroup of cases with cytopenia. Among device-related infections, 33% were managed with implant retention. Median follow-up was 630 days and overall cure rate 83%; among failures (n = 8), 63% were device-related infections. CONCLUSIONS: Long-term use of tedizolid was effective, showing a better safety profile with less myelotoxicity and lower drug-drug interaction than linezolid. Confirmation of these advantages could make tedizolid the oxazolidinone of choice for most of osteoarticular infections.

Effect of an awareness campaign on the diagnosis and clinical impact of primary immunodeficiency. / Efecto de una campaña de concienciación en el diagnóstico e impacto clínico de la inmunodeficiencia primaria.

BACKGROUND AND OBJECTIVES: Predominantly antibody deficiencies are the most prevalent primary immunodeficiency (PID) in adults. These are rare diseases difficult to diagnose. Therefore, they are diagnosed late. This study aims to evaluate whether an awareness campaign of PIDs among physicians is associated with an increase in number of diagnoses, a reduction in diagnostic delay and diagnosis at earlier stages. PATIENTS AND METHODS: A single centre, interventional, quasi-experimental study was designed that included 2 periods, period 1 pre-intervention (1986-2008) and period 2 post-intervention (2009-2018). A descriptive comparative study of variables was carried out in both periods. RESULTS: 116 patients were included [27 (23.3%) in period 1 and 89 (76.7%) in period 2]. The incidence rate increased significantly (0.204 and 1.236/100,000habs./year; P < 0.05), the diagnosis delay tended to be lower (4 vs. 3.73 years). The reasons for diagnostic suspicion were diverse and the burden disease at diagnosis (expressed by bronchiectasis, altered spirometry, ability to generate antibodies by thymus-independent mechanism and need for substitute treatment) tended to decrease in period 2. CONCLUSIONS: Given the potentially serious complications of patients with late diagnosis of PIDs, it is necessary to create specialized multidisciplinary units, to unify assistance protocols and to design interventions to increase the knowledge of these entities.

Clinical and Epidemiological Characteristics of Streptococcus suis Infections in Catalonia, Spain.

Introduction: Streptococcus suis (S. suis) is a human zoonotic pathogen of occupational origin, with infection acquired through contact with live pigs or pig meat. Pig farming is one of Catalonia's biggest industries and as a result this region of Spain has one of the highest density pig populations per km2. The aim of our study was to describe the infections caused by S. suis occurring in that area over a 9-year period. Materials and Methods: A retrospective, multi-center study was carried out by searching records from 15 hospitals in Catalonia for the period between 2010 and 2019. Results: Over the study period altogether nine cases of S. suis infection were identified in five hospitals, with five of these cases occurring in the 2018-2019 period. The mean age of patients was 48 ± 8.9 years and all of them were males. Five patients (55.6%) worked in pig farms. The most frequent manifestation of infection was meningitis (5 cases; 55.6%) followed by septic arthritis (3 cases; 33.3%). None of the patients died at 30 days; nonetheless, 4 developed hearing loss as a long-term complication. Conclusion: The most commonly identified S. suis infection was meningitis. Over 50% of the episodes occurred in the last 2 years and have affected pig farm workers. Further surveillance is needed in order to know its prevalence.

High-dose intravenous immunoglobulins might modulate inflammation in COVID-19 patients.

The use of high-dose of intravenous immunoglobulins (IVIGs) as immunomodulators for the treatment of COVID-19-affected individuals has shown promising results. IVIG reduced inflammation in these patients, who progressively restored respiratory function. However, little is known about how they may modulate immune responses in COVID-19 individuals. Here, we have analyzed the levels of 41 inflammatory biomarkers in plasma samples obtained at day 0 (pretreatment initiation), 3, 7, and 14 from five hospitalized COVID-19 patients treated with a 5-d course of 400 mg/kg/d of IVIG. The plasmatic levels of several cytokines (Tumor Necrosis Factor, IL-10, IL-5, and IL-7), chemokines (macrophage inflammatory protein-1α), growth/tissue repairing factors (hepatic growth factor), complement activation (C5a), and intestinal damage such as Fatty acid-binding protein 2 and LPS-binding protein showed a progressive decreasing trend during the next 2 wk after treatment initiation. This trend was not observed in IVIG-untreated COVID-19 patients. Thus, the administration of high-dose IVIG to hospitalized COVID-19 patients may improve their clinical evolution by modulating their hyperinflammatory and immunosuppressive status.

Multicentre, randomised, open-label, phase IV-III study to evaluate the efficacy of cloxacillin plus fosfomycin versus cloxacillin alone in adult patients with methicillin-susceptible Staphylococcus aureus bacteraemia: study protocol for the SAFO trial.

INTRODUCTION: Methicillin-susceptible Staphylococcus aureus (MSSA) bacteraemia is a frequent condition, with high mortality rates. There is a growing interest in identifying new therapeutic regimens able to reduce therapeutic failure and mortality observed with the standard of care of beta-lactam monotherapy. In vitro and small-scale studies have found synergy between cloxacillin and fosfomycin against S. aureus. Our aim is to test the hypothesis that cloxacillin plus fosfomycin achieves higher treatment success than cloxacillin alone in patients with MSSA bacteraemia. METHODS: We will perform a superiority, randomised, open-label, phase IV-III, two-armed parallel group (1:1) clinical trial at 20 Spanish tertiary hospitals. Adults (≥18 years) with isolation of MSSA from at least one blood culture ≤72 hours before inclusion with evidence of infection, will be randomly allocated to receive either cloxacillin 2 g/4-hour intravenous plus fosfomycin 3 g/6-hour intravenous or cloxacillin 2 g/4-hour intravenous alone for 7 days. After the first week, sequential treatment and total duration of antibiotic therapy will be determined according to clinical criteria by the attending physician.Primary endpoints: (1) Treatment success at day 7, a composite endpoint comprising all the following criteria: patient alive, stable or with improved quick-Sequential Organ Failure Assessment score, afebrile and with negative blood cultures for MSSA at day 7. (2) Treatment success at test of cure (TOC) visit: patient alive and no isolation of MSSA in blood culture or at another sterile site from day 8 until TOC (12 weeks after randomisation).We assume a rate of treatment success of 74% in the cloxacillin group. Accepting alpha risk of 0.05 and beta risk of 0.2 in a two-sided test, 183 subjects will be required in each of the control and experimental groups to obtain statistically significant difference of 12% (considered clinically significant). ETHICS AND DISSEMINATION: Ethical approval has been obtained from the Ethics Committee of Bellvitge University Hospital (AC069/18) and from the Spanish Medicines and Healthcare Product Regulatory Agency (AEMPS, AC069/18), and is valid for all participating centres under existing Spanish legislation. The results will be presented at international meetings and will be made available to patients and funders. TRIAL REGISTRATION NUMBER: The protocol has been approved by AEMPS with the Trial Registration Number EudraCT 2018-001207-37. ClinicalTrials.gov Identifier: NCT03959345; Pre-results.

A multicentre analysis of Nocardia pneumonia in Spain: 2010-2016.

OBJECTIVE: To analyse all cases of Nocardia pneumonia occurring between 2010 and 2016 in five Spanish hospitals. METHODS: This was a retrospective observational analysis of clinical and microbiological data collected from 55 cases of Nocardia pneumonia. RESULTS: There were one to 20 cases per hospital and six to nine cases per year. Chronic obstructive pulmonary disease, bronchiectasis, and asthma were the main predisposing underlying respiratory conditions. Thirty-four patients were receiving systemic and/or inhaled corticosteroids prior to infection, eight had neoplasia, and six had haematological malignancies. Clinical and radiological findings were common to pneumonia of other infectious aetiologies, except for the frequent presence of nodules and cavitation. Overall, the 1-year mortality was high (38.2%), and mortality was directly related to the pulmonary disease in 15 patients (27.3%). The most frequently identified species were N. cyriacigeorgica (n=21), N. abscessus (n=8), and N. farcinica (n=5). All Nocardia isolates were susceptible to linezolid and all but two were susceptible to amikacin and trimethoprim-sulfamethoxazole. CONCLUSIONS: Nocardia pneumonia-associated mortality remains high, probably because of the debilitated status of patients in whom this pathogen is able to cause pulmonary infection.

[Low mortality rate in an outbreak of Legionnaires' disease: correlation with the cytopathogenity study]. / Baja mortalidad en un brote de enfermedad del legionario: correlación con el estudio de citopatogenicidad.

BACKGROUND: In 2001 an outbreak of Legionnaires' diseases occurred in Murcia, Spain, with one of the lowest known rates of associated mortality. We describe the clinical data of a subgroup of patients, and present the results from molecular and virulence studies to correlate the lower mortality of the overall series with the strain virulence. PATIENTS AND METHODS: A subgroup of 86 patients from the outbreak of Legionnaires'disease was prospectively included. Demographic, risk factors and clinical evolution data were obtained. Moreover, we performed a pulsed field gel electrophoresis and cytopathogenicity assay of the Murcia outbreak that were compared with other unrelated Legionella isolates. RESULTS: Sixty-nine (77.9%) patients were males. The mean age of the patients was 58.2 years (range: 32-87). Smoking was the most frequent risk factor in 62 patients (71.7%) and 61 patients (70.2%) had underlying diseases. Clinical, laboratory and radiological manifestations were compatible with the atypical pneumonia syndrome. The mortality rate was 3.2%. All the clinical L. pneumophila isolates analyzed by PFGE showed the same subtype. When analyzing theses strains together with other Legionella strains, they were included in the group with lower virulence in the cytopathogenicity study. CONCLUSIONS: The most outstanding data in this subgroup of patients were: male-sex, smoking, atypical clinical manifestations and low mortality. The low virulence of this molecular genotype of L. pneumophila may be responsible, in part, for the low mortality observed in the outbreak in Murcia.

Legionella SBT applied directly to respiratory samples as a rapid molecular epidemiological tool.

Legionnaires' disease (LD) is an atypical pneumonia caused by the inhalation of Legionella. The methods used for the diagnosis of LD are direct culture of respiratory samples and urinary antigen detection. However, the sensitivity of culture is low, and the urinary antigen test is specific only for L. pneumophila sg1. Moreover, as no isolates are obtained, epidemiological studies cannot be performed. The implementation of Nested-sequence-based typing (Nested-SBT) makes it possible to carry out epidemiological studies while also confirming LD, especially in cases caused by non-sg 1. Sixty-two respiratory samples from patients with Legionella clinically confirmed by positive urinary antigen tests were cultured and tested by Nested-SBT, following the European Study Group for Legionella Infections (ESGLI) protocol. Only 2/62 (3.2%) respiratory samples were culture-positive. Amplification and sequencing of Nested-SBT genes were successfully performed in 57/62 samples (91.9%). The seven target genes were characterised in 39/57 (68.4%) respiratory samples, and the complete sequence type (ST) was obtained. The mip gene was the most frequently amplified and sequenced. Nested-SBT is a useful method for epidemiological studies in culture-negative samples, achieving a 28.7-fold improvement over the results of culture studies and reducing the time needed to obtain molecular epidemiological results.

Genotypic variability and persistence of Legionella pneumophila PFGE patterns in 34 cooling towers from two different areas.

Genotypic variability and clonal persistence are important concepts in molecular epidemiology as they facilitate the search for the source of sporadic cases or outbreaks of legionellosis. We studied the genotypic variability and persistence of Legionella pulsed-field gel electrophoresis (PFGE) patterns over time (period > 6 months) in 34 positive cooling towers from two different areas. In area A, radius of 70 km, 52 indistinguishable PFGE patterns were differentiated among the 27 cooling towers. In 13 cooling towers we observed >or= 2 PFGE patterns. Each cooling tower had its own indistinguishable Legionella PFGE pattern which was not shared with any other cooling tower. In area B, radius of 1 km, 10 indistinguishable PFGE patterns were obtained from the seven cooling towers. In four, we observed >or= 2 PFGE patterns. Three of these 10 indistinguishable PFGE patterns were shared by more than one cooling tower. In 27 of 34 cooling towers the same PFGE pattern was recovered after 6 months to up to 5 years of follow-up. The large genotypic diversity of Legionella observed in the cooling towers aids in the investigation of community outbreaks of Legionnaires' disease. However, shared patterns in small areas may confound the epidemiological investigation. The persistence of some PFGE patterns in cooling towers makes the recovery of the Legionella isolate causing the outbreak possible over time.

Persistence of Legionella in hospital water supplies and nosocomial Legionnaires' disease.

The molecular epidemiology of clinical and environmental Legionella species isolates was studied in seven hospitals from 1989 to 2006. The number of environmental pulsed field gel electrophoresis (PFGE) patterns ranged from one to nine according to the hospital. Genomic PFGE pattern persistence was observed in 71% of the hospitals, even after 17 years in some hospitals, and the relationship between environmental and clinical isolates was established. The isolates associated with hospital-acquired Legionnaires' disease corresponded to the persistent environmental PFGE patterns of Legionella pneumophila in potable water supplies.

Impact of copper and silver ionization on fungal colonization of the water supply in health care centers: implications for immunocompromised patients.

Copper and silver ionization is a well-recognized disinfection method to control Legionella species in water distribution systems in hospitals. These systems may also serve as a potential indoor reservoir for fungi. The prevalence of fungi was significantly lower in ionized than in nonionized water samples from health care facilities. The clinical consequences of this finding require further investigation.

Prevalence of and risk factors for methicillin-resistant Staphylococcus aureus carriage at hospital admission.

To determine the prevalence of and risk factors for methicillin-resistant Staphylococcus aureus (MRSA) carriage at the time of admission to our hospital, we screened the medical records of 1,128 patients for demographic and clinical data. The antimicrobial resistance pattern and genotype of MRSA isolates were studied. The prevalence of MRSA carriage at hospital admission was 1.4%. Older patients and patients previously admitted to healthcare centers were the most likely to have MRSA carriage at admission.

Microbiology and Epidemiology of Legionnaire's Disease.

Legionnaire's disease (LD) is the pneumonic form of legionellosis caused by aerobic gram-negative bacilli of the genus Legionella. Individuals become infected when they inhale aerosolized water droplets contaminated with Legionella species. Forty years after the identification of Legionella pneumophila as the cause of the 1976 pneumonia outbreak in a hotel in Philadelphia, we have non-culture-based diagnostic tests, effective antibiotics, and preventive measures to handle LD. With a mortality rate still around 10%, underreporting, and sporadic outbreaks, there is still much work to be done. In this article, the authors review the microbiology, laboratory diagnosis, and epidemiology of LD.