Two nosocomial outbreaks of sepsis caused by Serratia marcescens, which occurred in Tokyo were the following cases.
Case A: In July 1999, 10 inpatients admitted to the third floor ward of the General Hospital A, developed sudden onset of high fever, coagulation disorders (disseminated intravascular coagulation), and acute renal failure, of which 5 died. Twenty-one strains of Serratia marcescens were isolated from the inpatient's blood and urine, nurse fingers and environmental samples from floor and cooling tower. Serratia infection was strongly suspected as the cause of sepsis. These cases were defined as “inpatients who developed fever 38°C or more during July 26 to 29 and from whom S. marcescens was isolated by blood culture”. Ten isolates were detected from the blood. In order to investigate the background of S. marcescens isolation in the hospital and to compare molecular and biochemical characteristics of S. marcescens, cultures were attempted from samples of other inpatients and staffs and hospital environment. Those were classified into 9 groups by various different typings: biotyping with Api Rapid 20; susceptibility typing of antimicrobial agents tested; pulsed-field gel electrophoresis (PFGE) typing of Spe I-or Xba I-restricted chromosome. All 10 isolates causing sepsis were found to be in the same group.
Case B: In January 2002, 24 inpatients, admitted to Neurosurgical Hospital B, developed sudden onset of high fever, of which 7 died. S. marcescens was isolated from a towel, environmental samples and inpatients. These cases were defined as “inpatients who developed fever of 38.5°C and S. marcescens isolated by blood culture”. Twelve strains were isolated from the blood samples in 12 cases. In order to investigate the background of S. marcescens isolation in the hospital, cultures were attempted from other inpatient's urine and environmental samples from medical tape, Tshake and a towel. These isolates were classified into 3 groups by the previous typings; biotyping with Api Rapid 20; susceptibility typing of antimicrobial agents tested; and PFGE typing. All 12 isolates in 12 cases were found to be in the same group.
These cases of 2 nosocomial outbreaks of sepsis were defined as “in-patient who developed high fever and S. marcescens isolated by blood culture”. However in both cases transmission routes of Serratia infection remain unknown by field investigation.

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Arbekacin-resistant, methicillin-resistant Staphylococcus aureus was frequently isolated in Saitama Medical School Hospital during 1996 and 1998. The minimum inhibitory concentration for ABK was 8μg/ml in 14 strains, 16μg/ml in 6 strains, and 32μg/ml in 2 strains. The maximum isolation rate of these resistant strains in one month was 8%. Use of ABK in the hospital did not increase during the same period. The infection control team (ICT) of the hospital recognized the increase of resistant strains and started intervention for the hospital staff. The ICT instructed the staff of each ward to follow standard precautions for the prevention of nosocomial infections and the risk of ABKresistant MRSA was explained repeatedly. Thereafter, the isolation rate decreased to 3%.
An epidemiological study was done using 22 strains of ABK-resistant MRSA that were isolated in this period. The strains originated from different patients and from 10 different wards, which were designated as wards A to J. Eight strains were isolated from surgical ward A, followed by the other wards (ward B: 3, C: 2, D: 2, E: 2, F: 1, G: 1, H: 1, I: 1, J: 1). The specimens from which ABKresistant MRSA were isolated were as follows, : sputum: 4, wound: 4, decubitus ulcer: 4, urine: 2, pus: 2, blood: 1, central venous catheter: 1, drainage tube: 1, tracheal aspirate: 1, skin: 1, stool: 1. Several investigations were done using these strains. Sensitivity tests for ABK, VCM, MINO, LVFX, FOM, IPM were performed by the standard method of the Japan Society for Chemotherapy. Coagulase types were determined. Production of toxic shock syndrome toxin-1 (TSST-1), enterotoxin, and β-lactamase was assayed. Pulse-field gel electrophoresis (PFGE) using Sma I was also done and differences were compared.
Seven of the 8 strains from ward A showed the same drug sensitivity profile and biological phenotype. Two of the 3 strains from ward B and 2 strains from ward C were also identical by these methods. Six of the 8 strains from ward A were also identical by PFGE. These 6 isolates showed the same drug sensitivity pattern, same coagulase type, and same production of TSST-1 and enterotoxin. Two other strains from ward B, one strain from ward F, and one from ward I also showed the same PFGE pattern, drug sensitivity profile, and toxin profile as the 6 strains from ward A.
Our data show that the same strains were transmitted around the hospital during the study period, although serious nosocomial infections due to ABK-resistant MRSA were avoided. Thus, intervention by the ICT in each ward was effective. ABK-resistant MRSA should be recognized as an important hospital pathogen and should be surveyed consistently.

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Between February and July 2001, 15 patients were diagnosed as Clostridium difficile-associated diarrhea in a ward of hematological neoplasm and lung cancer in a cancer center hospital. Of these 15 patients, 10 had malignant lymphoma, and 12 and 11 had exposure to antimicrobial agents and cancer chemotherapy, respectively, before the onset of diarrhea. Toxin A-positive, toxin B-positive (A+B+) C. difficile was recovered from five patients and the remaining 10 patients suffered from diarrhea caused by toxin A-negative, toxin B-positive (A-B+) strains. All of the 10A-B+isolates represented an identical banding pattern by PCR ribotyping and classified into one type (two subtypes) by pulsed field gel electrophoresis typing, indicating that a nosocomial outbreak of diarrhea caused by A-B+C. difficile occurred among the patients hospitalized on this ward. Detection of toxin A in stool specimens by a toxin A detection kit was performed on 14 patients. Although two patients who carried A+B+strains were positive for toxin A assay, toxin A detection test was negative in 12 patients including 10 patients with A-B+C. difficile infection. Diagnosis of C. difficile-associated diarrhea by combination of toxin A assay in feces and culture of C. difficile could successfully lead to recognition of an outbreak caused by A-B+C. difficile in a cancer center hospital.

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Using serum specimens from patients with alveolar hydatidosis (AH) in Hokkaido, we assessed the usefulness of “Echinococcus Western Blot IgG” (the French immuoblot assay, FIA), which has recently been launched from Ldbio Diagnostics (Lyon, France) as new commercial immunoblot assay kit of immunodiagnosis of Echinococcus infections. Eighty serum specimens were used for the present study: 64 preoperative sera and nine postoperative sera, which were taken from AH patients in Hokkaido, and seven sera from persons who were ELISA (enzyme-linked immunosorbent assay)-positive in mass screening which was conducted for checking on Echinococcus infections in Hokkaido since 1982.
When the 64 preoperative sera were examined by the Western blotting method (the Hokkaido method of Western blotting, HWB) which had been carried out at Hokkaido Institute of Public Healthbetween 1987 and 1993, it was found that 53 cases were positive and six cases were quasi-positive, i. e. the rate of the positive cases including quasi-positive cases was 92.2%.
From immunostaining patterns, HWB-positive sera could be grouped in two types: the complete type, which showed a pattern of multiple bands containing the 55 and 66 kDa bands, and the incomplete type, which showed patterns of only few bands containing the AH-specific polysaccharide antigen named C antigen. Forty-three of the 53 HWB-positive sera were of the complete type and the residue was of the incomplete type.
On the other hand, when the 64 preoperative sera were examined by FIA, 60 sera (93.8%) were judged to be positive and the others as negative sera. On the basis of the interpretation of immunostaining patterns described in the instruction manual, 47 (78.3%) of the 60 positive sera were regarded as pattern P3, five (8.3%) as pattern P4, and eight (13.3%) as pattern P5. All of the completetype sera were regarded as P3, indicating high antibody titers. Contrarily, most of the incompletetype or quasi-positive sera resulted in other patterns such as P4 and P5, indicating low antibody titers. Of 5 HWB-negative sera, two were FIA-positive (which showed P3 and P5 patterns respectively), however their immunoreactions were significantly low.
Therefore, apart from interpretation of pathological conditions of cases with exceedingly low antibody titers, FIA may be able to give a serologically clear interpretation to HWB-quasi-positivecases, indicating that it is a highly sensitive and useful method for immunodiagnosis of Echinococcus infections.

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A 31-year-old male was admitted to Toranomon Hospital because of a cough and bilateral patchy infiltrates shown on the chest radiograph. He had been well prior to admission. Chest CT scan revealed patchy areas of air-space consolidation with air-bronchogram and adjacent ground-glass opacities, suggestive of bronchiolitis obliterans organizing pneumonia (BOOP). Transbronchial lung biopsy specimen confirmed the formation of epithelioid cell granulomas without necrosis and the coexistence of organizing pneumonia. The titer of serum cryptococcal antigen increased to 1: 256. According to these findings, a diagnosis of primary pulmonary cryptococcosis was made, although cryptococci were neither recognized in the specimen nor cultured from the bronchial lavaged fluid. Chest radiograph showed spontaneous regression in a short period of time. However, itraconazole was administered for the prolonged cough, and the symptom disappeared. The titer of serum cryptococcal antigen decreased to 1: 16 after the therapy. Pulmonary cryptococcosis should be considered as one of the differential diagnoses when chest CT scan shows combined air-space consolidation and ground-glass opacities.

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