A mortality prediction rule for non-elderly patients with community-acquired pneumonia.

BACKGROUND: No mortality prediction rule is suited for non-elderly patients with community-acquired pneumonia. Therefore, we tried to create a mortality prediction rule that is simple and suitable for non-elderly patients with community-acquired pneumonia. METHODS: Because of low mortality at young age, we used information from an administrative database that included A-DROP data. We analysed the rate and risk factors for in-hospital community-acquired pneumonia-associated death among non-elderly patients and created a mortality prediction rule based on those risk factors. RESULTS: We examined 49,370 hospitalisations for patients aged 18-64 years with community-acquired pneumonia. The 30-day fatality rate was 1.5%. Using regression analysis, five risk factors were selected: patient requires help for feeding, the existence of malignancy, confusion, low blood pressure, and age 40-64 years. Each risk factor of our proposed mortality risk scoring system received one point. A total point score for each patient was obtained by summing the points. The negative likelihood ratio for the score 0 group was 0.01, and the positive likelihood ratio for the score ≥4 group was 19.9. The area under the curve of the risk score for non-elderly (0.86, 95% confidence interval: 0.84-0.87) was higher than that of the A-DROP score (0.72, 95% confidence interval: 0.70-0.74) (P < 0.0001). CONCLUSIONS: Our newly proposed mortality risk scoring system may be appropriate for predicting mortality in non-elderly patients with community-acquired pneumonia. It showed a possibility of a better prediction value than the A-DROP and is easy to use in various clinical settings.

Novel Features of Eukaryotic Photosystem II Revealed by Its Crystal Structure Analysis from a Red Alga.

Photosystem II (PSII) catalyzes light-induced water splitting, leading to the evolution of molecular oxygen indispensible for life on the earth. The crystal structure of PSII from cyanobacteria has been solved at an atomic level, but the structure of eukaryotic PSII has not been analyzed. Because eukaryotic PSII possesses additional subunits not found in cyanobacterial PSII, it is important to solve the structure of eukaryotic PSII to elucidate their detailed functions, as well as evolutionary relationships. Here we report the structure of PSII from a red alga Cyanidium caldarium at 2.76 Å resolution, which revealed the structure and interaction sites of PsbQ', a unique, fourth extrinsic protein required for stabilizing the oxygen-evolving complex in the lumenal surface of PSII. The PsbQ' subunit was found to be located underneath CP43 in the vicinity of PsbV, and its structure is characterized by a bundle of four up-down helices arranged in a similar way to those of cyanobacterial and higher plant PsbQ, although helices I and II of PsbQ' were kinked relative to its higher plant counterpart because of its interactions with CP43. Furthermore, two novel transmembrane helices were found in the red algal PSII that are not present in cyanobacterial PSII; one of these helices may correspond to PsbW found only in eukaryotic PSII. The present results represent the first crystal structure of PSII from eukaryotic oxygenic organisms, which were discussed in comparison with the structure of cyanobacterial PSII.

The risk factors for developing of chronic pulmonary aspergillosis in nontuberculous mycobacteria patients and clinical characteristics and outcomes in chronic pulmonary aspergillosis patients coinfected with nontuberculous mycobacteria.

Patients with chronic pulmonary aspergillosis (CPA) have a poor prognosis and CPA occurs in patients with various underlying diseases. Recently, the number of patients with CPA complicated by nontuberculous mycobacteria (NTM) has increased. Additionally, complications of both diseases have several problems like drug interactions. Since the impact of NTM on the outcome of CPA is not well understood, we investigated the risk factors for developing CPA and the clinical characteristics of CPA patients with or without NTM. We retrospectively investigated the medical records of NTM and CPA patients who were admitted to Nagasaki University Hospital between April 2008 and September 2013. Comorbid diseases, causative microorganisms, radiological findings, and outcomes were evaluated. During the study period, 82 and 41 patients were diagnosed as having NTM and CPA, respectively. Nine patients were coinfected with NTM and CPA, and cavitary type NTM and steroid usage were independent risk factors of development of CPA. Mortality rates in the coinfection group were significantly higher than those of the NTM without CPA group (P = .003, log-rank test). The rate of treatment initiation in the co-infection group (33.3%) was significantly lower than in the CPA without NTM group (84.4%) (P = .006). However, there were no significant differences in cumulative survival rate between both groups (P = .760, log-rank test). Cavity formation and steroid usage were the independent risk factors for NTM patients to develop CPA within long observation period, and development of CPA made outcomes poor. It is important to diagnose the development of CPA early and initiate treatment for CPA.

[Pathogenesis of chronic necrotizing pulmonary aspergillosis].

Chronic necrotizing pulmonary aspergillosis (CNPA) is a slowly progressive inflammatory destruction of lung tissue due to Aspergillus infection. The main radiographic features are chronic pulmonary infiltrates, progressive cavitation, and subsequent aspergilloma formation. Although pre-existing cavity is not seen, the presence of pre-existing airspaces such as emphysematous bullae, cannot be excluded. Chronic cavitary pulmonary aspergillosis (CCPA), which is synonymous with complex aspergilloma, shows one or more pre-existing and / or newly formed pulmonary cavities that may or may not contain an aspergilloma, and cavity expansion and / or increasing pericavitary infiltrates. CNPA can be distinguished from CCPA by careful observation of progression of the cavitary lesion if a series of adequate radiography films are available. In some cases, however, it is difficult to distinguish the two subtypes if prior radiographs are not available Aiso, intermediate or overlapping types may exist. We therefore clinically and therapeutically proposed the syndrome including both CNPA and CCPA as chronic progressive pulmonary aspergillosis (CPPA).

Clinical features of pulmonary cryptococcosis in non-HIV patients in Japan.

OBJECTIVE: To clarify the clinical features of pulmonary cryptococcosis in Japanese non-HIV population. METHODS: Retrospective investigation of 151 pulmonary cryptococcosis cases between 1977 and 2012 was executed. The underlying disease (UDs), aggravating factors, radiological characteristics, and treatment were examined. RESULTS: Sixty-seven patients (44.4%) had no UDs. The common UDs were diabetes (32.1%) followed by hematologic disease (22.6%), and collagen disease (22.6%). Peripherally distributed pulmonary nodules/masses were most commonly seen. Lesions in the right middle lobe (p = 0.01) and air bronchogram (P = 0.05) were significantly more frequent, respectively, in patients with UDs than patients without them. Azoles were mainly selected for the patients without meningoencephalitis. Mean treatment duration for patients with and without UDs was 6.64 and 2.87 months, respectively. Patients whose pulmonary nodules improved after treatment continued to experience gradual reduction of cryptococcosis antigen titers, even if antigen titers were positive at the time of treatment cessation. The average time for antigen titers to become negative after treatment cessation was 13.1 and 10.7 months for patients with and without UDs, respectively. When groups were compared according to the presence of meningoencephalitis complications, deaths, and survivals, factors contributing to cryptococcosis prognosis included higher age, hypoproteinemia, hypoalbuminemia, steroid use, high C-reactive protein levels, and meningoencephalitis complications. CONCLUSIONS: It is crucial to consider the presence of UDs and meningoencephalitis for the choice of antifungals and treatment duration for cryptococcosis in non-HIV patients. Three- and six months-administration of azoles for pulmonary cryptococcosis with or without UDs, respectively is reasonable.

A fatal case of acute myocardial infarction following the improvement of influenza A(H1N1)pdm2009-related acute myocarditis.

A 52-year-old Indian man was hospitalized due to dyspnea and a high fever caused by influenza A(H1N1)pdm2009. Elevated cardiac enzymes, a chest X-ray showing bilateral infiltrative shadows, cardiomegaly and pleural effusion and echocardiography indicating diffuse hypokinesis of the left ventricle suggested cardiac failure due to acute myocarditis. Owing to the administration of combined modality therapy, including steroids and intravenous γ-globulin, the patient's clinical symptoms of influenza completely resolved. However, he suddenly complained of epigastric pain due to acute myocardial infarction and died. This report is an educational case, the results of which suggest that greater attention should be paid to the potential for myocardial infarction even after an influenza virus infection is found to improve.

Importance of functional assessment in the management of community-acquired and healthcare-associated pneumonia.

OBJECTIVE: In Japan, the number of elderly people who have difficulties performing the activities of daily living (ADLs) is increasing. The objective of this study was to assess the relationship between ADL and the clinical characteristics of pneumonia. METHODS: We conducted a retrospective study of 219 adult patients hospitalized due to pneumonia [151 patients with community-acquired pneumonia (CAP) and 68 patients with healthcare-associated pneumonia (HCAP)]. CAP, HCAP, and all the patients were stratified into two groups using a modified version of the Katz index of five ADLs as follows: independent in all ADLs or dependent in one to three ADLs (CAP-A, HCAP-A, and All-A groups) and dependent in four or five ADLs (CAP-B, HCAP-B, and All-B groups). Disease severity, microbiological findings, and mortality were compared between the groups. RESULTS: As the ability to perform ADLs declined, A-DROP scores (the CAP severity measurement index) increased significantly in CAP (CAP-A: 1.1±1.1, CAP-B: 2.6±1.1), HCAP (HCAP-A: 2.0±1.0, HCAP-B: 2.8±1.0), and all patients (All-A: 1.3±1.1, All-B: 2.8±1.0). Thirty-day mortality was higher in the CAP-B (23.1%) and All-B (19.2%) groups than in the CAP-A (0.7%) and All-A (1.8%) groups, respectively. A multivariate Cox proportional hazards analysis showed an ADL score ≥ four to be a significant predictor of 30-day mortality in CAP patients [hazard ratio (HR), 19.057; 95% confidence interval (CI), 1.930-188.130] and in all patients (HR, 8.180; 95% CI, 1.998-33.494). CONCLUSION: A functional assessment using a modified version of the Katz index is useful for the management of CAP and HCAP patients.

Three cases of concurrent infection with Mycobacterium tuberculosis and Cryptococcus neoformans.

Impaired cellular-mediated immunity is a known risk factor for both tuberculosis and cryptococcosis. However, pulmonary cryptococcosis associated with pulmonary tuberculosis is rare. We herein describe three cases of concurrent infection with Mycobacterium tuberculosis and Cryptococcus neoformans. All patients had underlying diseases; all three had uncontrolled diabetes mellitus, and other underlying diseases were liver cirrhosis, malignancy, and rheumatoid arthritis requiring long-term steroid use. We also review other relevant reports.

Concurrent subcutaneous candidal abscesses and pulmonary cryptococcosis in a patient with diabetes mellitus and a history of corticosteroid therapy.

A 50-year-old man with a history of long-term corticosteroid treatment following adrenalectomy for Cushing's syndrome and uncontrolled diabetes mellitus was admitted for an examination of an abnormal thoracic shadow. Cryptococcal serum antigens were positive, and the histopathology of a lung biopsy showed encapsulated yeast resembling Cryptococcus neoformans. On admission, the serum ß-D-glucan level was approximately twice the cutoff value, several nodules were observed on both legs and magnetic resonance imaging revealed subcutaneous abscesses. Candida albicans was identified from needle aspirates, and the patient was successfully treated with fluconazole and flucytosine. We herein report the first case of concurrent C. albicans skin abscesses and pulmonary cryptococcosis.

Efficacy of combination therapy with oseltamivir phosphate and azithromycin for influenza: a multicenter, open-label, randomized study.

BACKGROUND: Macrolides have antibiotic and immunomodulatory activities, which may have a favorable effect on the clinical outcome of patients with infections, including influenza. This study aimed to evaluate the effects of combination therapy with an anti-influenza agent, oseltamivir, and a single-dose formulation of azithromycin (AZM), which has been used for influenza-related secondary pneumonia, on influenza patients. The primary endpoint was a change in the expression levels of inflammatory cytokines. Secondary endpoints were the time required for resolution of influenza-related symptoms, incidence of complications, and adverse reactions. METHODS: Patients with seasonal influenza were enrolled in this multicenter, open-label, randomized study. Patients were stratified according to the presence of a high risk factor and were randomized to receive combination therapy with oseltamivir plus an extended-release formulation of AZM (combo-group) or oseltamivir monotherapy (mono-group). RESULTS: We enrolled 107 patients and randomized them into the mono-group (56 patients) or the combo-group (51 patients). All patients were diagnosed with influenza A infection, and none of the patients had comorbid pneumonia. Statistically significant differences were not observed in the expression levels of inflammatory cytokines and chemokines between the 2 groups. The maximum temperature in the combo-group was lower than that in the mono-group on day 3 through day 5 (p = 0.048), particularly on day 4 (p = 0.037). CONCLUSION: To our knowledge, this is the first prospective, randomized, clinical trial of oseltamivir and AZM combination therapy for influenza. Although the difference in inflammatory cytokine expression level was not statistically significant, combination therapy showed an early resolution of some symptoms. NAME OF REGISTRY: University hospital Medical Information Network (UMIN). TRIAL REGISTRATION NO: UMIN000005371.

Efficacy of aerosolized liposomal amphotericin B against murine invasive pulmonary mucormycosis.

Invasive pulmonary mucormycosis is a life-threatening fungal infection encountered in immunocompromised patients. An intravenous high-dose lipid formulation of amphotericin B, such as liposomal amphotericin B (L-AMB), is the recommended treatment. The efficacy of inhaled L-AMB against mucormycosis has not been evaluated. We evaluated the efficacy of inhaled aerosolized L-AMB in murine invasive pulmonary mucormycosis. ICR female mice were immunosuppressed with cortisone acetate and cyclophosphamide and challenged on day 0 with 1 × 106 conidia of Rhizopus oryzae (TIMM 1327) intratracheally. Infected mice were assigned to one of the following 3 treatment groups: (i) control, (ii) treatment only (aerosolized L-AMB from day 1-5 after challenge), and (iii) prophylaxis followed by treatment (aerosolized L-AMB from day -2 to 5 before and after challenge). Survival was monitored until 12 days after challenge. For fungal-burden and histopathological examination, mice were sacrificed 4 h after treatment on day 3. Numbers of colony-forming units per lung were calculated. To study the distribution of AMB after inhalation of L-AMB, immunohistochemical studies using AMB antibody were performed. Aerosolized L-AMB significantly improved survival rate and decreased fungal burden compared with control group, and histopathology findings were superior to those of control group. However, no significant differences were detected between the treatment-only and prophylaxis followed by treatment groups. Immunohistochemical analysis showed that L-AMB was promptly distributed in lung tissue after inhalation therapy. Aerosolized L-AMB showed modest efficacy against R. oryzae infection in mice treated after fungal challenge. Prophylaxis with aerosolized L-AMB was not effective in this animal model.

Pathogenesis and clinical features of chronic pulmonary aspergillosis - is it possible to distinguish CNPA and CCPA clinically?

BACKGROUND: The pathogenesis of chronic pulmonary aspergillosis (CPA) including chronic necrotizing pulmonary aspergillosis (CNPA), chronic cavitary pulmonary aspergillosis (CCPA), and simple aspergilloma (SA) has been poorly investigated. We examined all types of CPA cases with histopathological evidence to clarify the differences in pathogenesis and clinical features. METHOD: We searched for cases diagnosed as pulmonary aspergillosis by histopathological examination in Nagasaki University Hospital between 1964 and September 2010. All available clinical information including radiological findings were collected and analyzed. RESULT: We found 7, 5, 8, and 7 cases of proven CNPA, probable CNPA, CCPA, and SA, respectively. The radiograph of proven and probable CNPA was initially infiltrates or nodules that progress to form cavities with or without aspergilloma, whereas the radiograph of CCPA showed pre-existed cavities and peri-cavitary infiltrates with or without aspergilloma. The patients with proven and probable CNPA exhibited not only respiratory symptoms but also systemic symptoms and malnutrition. Aspergillus fumigatus was the most frequently isolated Aspergillus species (n = 14), however, Aspergillus niger was the predominant isolated species in proven CNPA cases (n = 4). CONCLUSION: Our data indicate that the cases with chronic infiltration, progressive cavitation, and subsequent aspergilloma formation should be diagnosed as CNPA, and the cases with pre-existed cavities showing peri-cavitary infiltrates with or without aspergilloma would mean CCPA. However, it may be difficult to distinguish the two subtypes if a series of adequate radiography films are not available. We propose the term "chronic progressive pulmonary aspergillosis (CPPA)" for the clinical syndrome including both CNPA and CCPA.

[Two cases of emphysematous urinary tract infections successfully treated with conservative management].

Emphysematous urinary tract infection is a rare, fulminant complication that is characterized by the presence of gas in the pelvicaliceal system, renal parenchyma, perinephric tissues and retroperitoneum. Surgical resection is usually regarded as the treatment of choice, however several studies have shown the safety and efficacy of conservative management under the correct diagnosis and appropriate antibiotic administration. We herein report on two cases of emphysematous urinary tract infection, pyelonephritis and cystitis infected with ESBL-producing Eschrerichia coli, complicated with diabetic mellitus which were successfully treated with conservative treatment.

[A case of influenza pneumonia following pneumococcal infection in an adult patient with concurrent encephalopathy with a lesion in the splenium of the corpus callosum].

A 35-year-old male patient had a fever, cough, and other symptoms since the end of December 2010. The patient then developed a high fever and decreased SpO2, suggesting possible pneumonia. The patient was admitted to our hospital on the 6th day of illness. Chest computed tomography revealed multiple infiltrative shadows and ground-glass opacities distributed in a patchy pattern in the bilateral lungs. An atypical pneumonia was suspected, and we initiated antibiotic treatment with minocycline. However, the patient developed consciousness disturbance in the afternoon of the 7th day of illness. The high fever persisted, suggesting the patient's poor response to minocycline treatment, which was then replaced with ciprofloxacin and imipenem/cilastatin on the 8th day of illness. Streptococcus pneumoniae was detected in the blood culture bottles submitted at the time of admission. A head magnetic resonance imaging performed on that day showed a high intensity area in the splenium of the corpus callosum, leading to a diagnosis of encephalopathy. Methylprednisolone pulse therapy and gamma globulin treatment were initiated. The patient then recovered consciousness gradually with improvement of inflammatory responses and imaging findings. Subsequently, an influenza virus (H1N1) antibody level was found to have increased from less than 10 times to 640 times. Thus, it was determined that the patient's pneumonia and encephalopathy were attributable to the influenza A (H1N1) pdm09 virus during the flu season and Streptcoccal infection. Combination therapy, such as steroid pulse treatment, appropriate antibiotics and gamma globulin preparation was effective for both the flu-induced mixed pneumonia and encephalopathy in this patient.

A case series of chronic necrotizing pulmonary aspergillosis and a new proposal.

Chronic necrotizing pulmonary aspergillosis (CNPA) is an indolent, cavitating process in the lungs resulting from invasion of lung tissue by Aspergillus spp. However, most previous reports have not found any clear evidence of parenchymal invasion, and clinical distinction between CNPA and chronic cavitary pulmonary aspergillosis (CCPA) is difficult. We performed a histopathological study of lung specimens obtained by autopsy, surgical resection, or biopsy to clarify the characteristic pathological and clinical features of CNPA. We present 4 cases of proven CNPA, diagnosed by histological demonstration of tissue invasion by the fungus, and present its clinical features. These 4 patients were male, and the mean age was 62 years (range, 51-75 years). Their underlying conditions were chronic obstructive pulmonary disease (n = 3), sequelae of pulmonary tuberculosis (n = 2), and diabetes mellitus (n = 1). Aspergillus precipitation tests were positive for 3; and Aspergillus antigen tests were positive for 2 on admission, and subsequently, for all 4. The isolated pathogens were Aspergillus niger for 1 and A. fumigatus for 1. Initial radiographic findings were infiltrates or nodular lesions, which slowly progressed and cavitated before the appearance of fungus balls. Although CNPA has characteristic pathological features, it is clinically difficult to distinguish CNPA from CCPA. We propose to use the term chronic progressive pulmonary aspergillosis for both CNPA and CCPA.

Necrotizing pneumonia due to femoral osteomyelitis caused by community-acquired methicillin-resistant Staphylococcus aureus.

A chest X-ray of a young healthy African-American man with acute respiratory failure revealed bilateral multiple nodular shadows in the lungs, while community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) was detected in blood and sputum cultures. Magnetic resonance imaging showed osteomyelitis of the left thigh, and computed tomography revealed bilateral cavitary lesions in the chest, indicating necrotizing pneumonia with pulmonary embolism caused by osteomyelitis as a result of infection with CA-MRSA. CA-MRSA should be suspected as a causative agent of severe community-acquired pneumonia, even in Japan, among patients who belong to communities at high risk of CA-MRSA infection.

[An adult case of influenza-associated encephalitis successfully treated with high dose intravenous immunoglobulins].

A 73-year-old man was admitted to our hospital with a high fever and left paresis. A rapid diagnosis test was positive for influenza A was positive by rapid diagnosis test and diffusion-weighted MRI imaging of the brain showed a high intensity lesion of the right cerebral peduncle. The patient was therefore diagnosed as having influenza A virus infection complicated with lacunar infarction. In spite of initial treatment with oseltamivir and anticoagulant therapy, he lost consciousness eight hours after admission. The high intensity lesion of the cerebral peduncle enlarged and new lesions in the thalamus, hippocampus and calcarine cortex were detected with brain MRI. Additionally, an electroencephalographic study showed an entire slow wave and as the other causative pathogens of central nerve system infection were not detected, the likely diagnosis was influenza-associated encephalitis. We administered a high dose of intravenous immunoglobulin since the low-grade fever and mild unconscious state had continued in spite of the treatment with methylprednisolone pulse therapy. His consciousness was restored and body temperature became normal immediately. We could confirm the efficacy of our treatment by measurement of IL-6 levels in the serum and cerebrospinal fluid during the entire clinical course. In conclusion, a high dose of intravenous immunoglobulin therapy might be one of the effective treatments for influenza-associated encephalitis.

Correlation between triazole treatment history and susceptibility in clinically isolated Aspergillus fumigatus.

This is the first report of a detailed relationship between triazole treatment history and triazole MICs for 154 Aspergillus fumigatus clinical isolates. The duration of itraconazole dosage increased as the itraconazole MIC increased, and a positive correlation was observed (r = 0.5700, P < 0.0001). The number of itraconazole-naïve isolates dramatically decreased as the itraconazole MIC increased, particularly for MICs exceeding 2 µg/ml (0.5 µg/ml versus 2 µg/ml, P = 0.03). We also examined the relationship between cumulative itraconazole usage and the MICs of other azoles. A positive correlation existed between itraconazole dosage period and posaconazole MIC (r = 0.5237, P < 0.0001). The number of itraconazole-naïve isolates also decreased as the posaconazole MIC increased, particularly for MICs exceeding 0.5 µg/ml (0.25 µg/ml versus 0.5 µg/ml, P = 0.004). Conversely, the correlation coefficient obtained from the scattergram of itraconazole usage and voriconazole MICs was small (r = -0.2627, P = 0.001). Susceptibility to three triazole agents did not change as the duration of voriconazole exposure changed. In addition, we carried out detailed analysis, including microsatellite genotyping, for isolates obtained from patients infected with azole-resistant A. fumigatus. We confirmed the presence of acquired resistance to itraconazole and posaconazole due to a G54 substitution in the cyp51A gene for a patient with chronic pulmonary aspergillosis after oral itraconazole therapy. We should consider the possible appearance of azole-resistant A. fumigatus if itraconazole is used for extended periods.

Bronchoalveolar lavage galactomannan for the diagnosis of chronic pulmonary aspergillosis.

Diagnosing chronic pulmonary aspergillosis (CPA) is complicated, and there are limited data available regarding the identification of galactomannan (GM) in clinical specimens to assist the detection of this infection. The purpose of this study was to evaluate the detection of GM in bronchoalveolar lavage fluid (BALF) and serum and to assess its utility for diagnosing CPA. We retrospectively reviewed the diagnostic and clinical characteristics of 144 patients, with and without CPA, in Nagasaki University Hospital, Japan, whose BAL and serum specimens were examined for the presence of GM. The Platelia Aspergillus enzyme immunoassay (PA EIA) was performed according to the manufacturer's instructions. The mean values of BALF GM antigen were 4.535 (range, 0.062-14.120) and 0.430 (range, 0.062-9.285) in CPA (18) and non-CPA (126) patients, respectively. The mean values of serum GM antigen were 1.557 (range, 0.232-5.397) and 0.864 (range, 0.028-8.956) in CPA and non-CPA patients, respectively. PA EIA of BALF is superior to the test with serum, with the optimal cut-off values for BALF and serum of 0.4 and 0.7, respectively. The sensitivity and specificity of PA EIA in BALF at a cut-off of 0.4 were 77.2% and 77.0%, respectively, whereas with serum at a cut-off of 0.7, they were 66.7% and 63.5%, respectively. GM testing using BALF showed reasonable sensitivity and specificity as compared to that using serum. Thus, assessing GM levels in BALF may enhance the accuracy of diagnosing CPA.

Active surveillance of methicillin-resistant Staphylococcus aureus with the BD GeneOhm MRSA™ assay in a respiratory ward in Nagasaki, Japan.

The utility of active surveillance cultures (ASCs) in respiratory wards, that do not have an associated intensive care unit (ICU), and the usefulness of the BD GeneOhm MRSA™ system for rapid detection of methicillin-resistant Staphylococcus aureus (MRSA) have not been previously evaluated in Japan. ASCs using conventional culture methods and the BD GeneOhm MRSA™ assay were conducted in adult inpatients between May 11, 2009 and November 10, 2009 in a respiratory ward, without an associated ICU, in Nagasaki University Hospital. The infection and colonization rates of MRSA acquired in this respiratory ward were both investigated. A total of 159 patients were investigated. Of these, 12 (7.5%) were found positive for MRSA by the BD GeneOhm MRSA™ assay and 9 (5.7%) were found positive by a conventional culture test upon admission. All cases were MRSA-colonized cases and cross-transmission was not found to occur during hospitalization. The BD GeneOhm MRSA™ assay had a sensitivity of 100% and a specificity of 98%. ASCs in our respiratory ward revealed that MRSA was brought in from other sites in some cases, and that current infection control measures in Nagasaki University Hospital are effective. The BD GeneOhm MRSA™ assay was proven to be a useful and rapid detection tool for MRSA.