Haemophilus influenzae type b (Hib) remains the leading cause of invasive bacterial infection in Japanese children. More than 110 countries that have included Hib conjugate vaccines in their routine vaccination programs have seen dramatical decrease in the incidence of Hib infections. In Japan, the vaccine has been introduced for voluntary immunization since December 2008 and has been provided free of charge only since January 2011.
This review reports the prevalence of Hib and its clones among healthy children and pediatric patients diagnosed with invasive or non-invasive Hib infections in Sado Island, Japan. Of 25 Hib isolates collected in this surveillance, 4 genotypic patterns (ST54-gBLPACR-III, ST54-gBLNAR-I/II, ST190-gBLNAS, and ST95- gBLPACR-I/II) were detected. These STs were double or triple-locus variants of each other. Under the same antimicrobial selective pressure, high prevalence of gBLPACR strain (76.0%) was confirmed in Hib isolates, while gBLPACR prevalence in nontypeable H. influenzae was very low (5.2%). These data suggested that each ST strain may be brought into Sado Island by different routes. We note that surveillance of healthy subjects to identify Hib carriers is important to understand their role in transmission of Hib.

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Epidemics of infectious diseases often occur in hospital wards handling patients with severe motor and intellectual disabilities. However, the causative pathogens are not identified in half of these epidemics. Recently, an epidemic occurred in 2 wards consecutively in the National Hospital Organization Ehime Hospital in March-April, 2010. In this epidemic, 18 of 40 patients in one ward and 14 of 60 patients in another ward showed symptoms, and human metapneumovirus (HMPV) was detected from pharyngeal and/or nasal swabs of 4 patients. Phylogenetic analysis of the viral genomes showed that the virus belonged to subgroup B2, and the same virus had spread consecutively in 2 wards. High fever lasted for 5.3 days on average in the 32 inpatients, was mostly over 38℃ and was accompanied by productive coughs. In the 4 patients in whom human HMPV was detected, the number of peripheral blood lymphocytes decreased but that of monocytes increased. Pneumonia developed in two patients as shown by chest radiography, and an increased number of peripheral blood neutrocytes and increased CRP levels were noted. Of the 151 inpatients, anti-human HMPV antibody was found in the sera of 143 (95%), and the relationship between high fever and antibody titer was not significant, indicating that HMPV infection could recur in spite of the presence of specific antibodies.<BR>Because human HMPV is highly prevalent, and causes high fever and pneumonia, hospital staff should be vigilant for any signs of this virus in hospital wards and take steps to prevent infection in long-term inpatients.

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Surveillance is very important for preventing the nosocomial spread of methicillin-resistant Staphylococcus aureus (MRSA), and the pulsed-field gel electrophoresis (PFGE) method has long been used to identify the infection source and route as a molecular and epidemiological genotyping method.
However, the use of the method in routine clinical laboratory measurements is difficult due to its complicated procedures.
Since a molecular and epidemiological genotyping kit based on the POT (Phage Open-reading Frames Typing) method has been developed, we examined 192 MRSA isolates newly detected from inpatients in our hospital in 2010 in order to investigate the usefulness of POT for surveying outbreaks of MRSA. Among the 192 isolates 118 were suspected of nosocomial spread by the previous method, which defined a MRSA detection at more than 48 hours after admission as a nosocomial spread. The POT method was introduced at our laboratory in 2010, and we were able to recognize 38 patients as having strongly suspected nosocomial MRSA infection with the POT method taking into consideration the infection situation, such as places (wards and transfer) and time (date of admission and date of collected samples).
Our Infection Control Division was confidently able to demonstrate the current condition of the nosocomial spread by providing the results to the clinical staff, who were also able to practice infection control confidently.
We concluded that the POT method was very useful and convenient for investigating MRSA isolates and evaluating collected data because no particular analysis other than the digitizing electrophoretic pattern method was necessary.

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Klebsiella oxytoca is an opportunistic pathogen and is isolated at the second highest frequency among genus Klebsiella from hospitalized patients. According to previous reports, the major virulence factors of K. pneumoniae include capsules and several kinds of pili, whereas the virulence factors of K. oxytoca have not been well investigated.
We noticed an increased frequency of K. oxytoca isolates from patients who had undergone a biliary tract operation in a general hospital from May through November, 2009. We then performed a PCR analysis of the virulence factors and an epidemiological analysis with capsular typing (serotyping) and pulsed field gel electrophoresis (PFGE) for K. oxytoca of 11 blood isolates and 10 bile isolates. As a result, serotypes of K9, K15, K26, K31, K43, K47, K55, K70, and K79 were identified in these strains, and K1 and K2 which are frequent serotypes in K. pneumoniae strains were not observed. Two blood isolates of the K55 serotype showed almost the same PFGE pattern, suggesting that these isolates were very closely related and caused cross-infection in a hospital ward. Strains of the K43 serotype were three blood isolates and 1 bile isolate, all of which showed different PFGE patterns. There were no common isolates among the blood and bile isolates. A PCR search revealed that fimH and mrkD genes which are relevant to type 1 and type 2 pili, respectively, were present in all strains, whereas kfuBC, an iron uptake gene, and cf29a were detected in only a few strains. Neither of the mucoid phenotype-related genes magA and rmpA was present in any strains. These results strongly suggest that type 1 and/or type 3 pili would have important roles in the pathogenesis of blood infection and bile infection caused by K. oxytoca.

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[Purpose] The BCG immunization has long been performed in Japan. Although the BCG immunization service is the responsibility of the municipality, the manner in which the BCG immunization is delivered differs from municipality to municipality. The purpose of this study was to clarify how the different manner of the BCG immunization delivery systems influenced the BCG immunization coverage.
[Methods] The study of BCG immunization coverage was conducted in the Tama area located in the western suburbs of Tokyo in 2004. The birth data and the immunization history by the age of 3 years were collected in the three-year-old health check-up from a total of 2,341 children residing in the Tama area. Based on the age at immunization for each child, the BCG immunization coverage was calculated according to the types of the BCG immunization delivery system. The immunization types were defined as follows ; the BCG immunization given on the occasion of the mass health check-up (Group 1); the exclusive mass BCG immunization in a monthly service(Group 2); the exclusive mass BCG immunization in a bimonthly service (Group 3); the exclusive mass BCG immunization in services of fewer than every two months (Group 4); and the immunization given on an individual basis by a general practitioner (Group 5).
A univariate analysis was performed to examine the relationship between the BCG immunization coverage by the age of 6 months and the difference among the BCG immunization delivery systems, followed by a multivariate regression analysis to adjust for the factors related to the demography, health care services and the socio-economic status of the municipalities.
[Results] Unadjusted odds ratios and adjusted odds ratios for BCG unimmunized children under the age of 6 months by the BCG immunization delivery manner groups were OR 1 reference, adj. OR1 referencein Group 1 ; OR 1.42 CI 0.87―2.29, adj. OR 4.01 CI 2.24―7.11 in Group 2 ; OR 4.96 CI 3.66―6.82, adj. OR 15.59 CI 10.10―24.49 in Group 3 ; OR 18.60 CI 13.77―25.49, adj. OR 48.17 CI 29.62―79.75 in Group 4 ; and OR 4.24 CI 2.86―6.31, adj. OR 15.61 CI 9.05―27.26 in Group 5. The univariate analysis and multivariate regression analysis revealed an influence of the BCG immunization delivery manner on the BCG immunization coverage.
[Conclusion] The choice of BCG immunization delivery manner is very important to raise the BCG immunization coverage. The BCG immunization given on the occasion of the mass health check-up and the high-frequent immunization service are thought to improve the BCG immunization coverage.

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Toxoplasmic encephalitis is a rare complication in patients with hematological malignancies. It is infrequently reported in patients undergoing allogeneic hematopoietic stem cell transplantation, much less in patients after conventional chemotherapy. A 75-year old female with acute myelogenous leukemia had an episode of aphasia, right homonymous hemianopsia, and consciousness disturbance 122 days after consolidation chemotherapy. Multiple enhancing space occupying lesions involving the left occipital lobe were seen on magnetic resonance imaging (MRI). HIV antibody was negative. Based on radiological findings, clinical presentation and positive Toxoplasma gondii serostatus, sulfadoxine and pyrimethamine were added. A rapid improvement was observed thereafter. Heightened awareness of the occurrence of toxoplasmic encephalitis, even in non-HIV patients, is needed for a better outcome.

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Mycobacterium marinum is a waterborne mycobacterium that commonly infects fish and amphibians worldwide, but transmission to humans can occasionally occur, typically as a granulomatous skin infection following minor hand trauma. Infection involving the lungs is very rare. We herein describe a case of M. marinum-associated pneumonia and pneumothorax.
In August 2008, an 81-year-old man was admitted to a hospital for detailed examination of weight loss and an abnormal shadow on chest imaging. Based on a sputum test, nontuberculous mycobacteriosis caused by M. marinum was diagnosed. At that time, the blood chemistry revealed no respiratory symptoms or inflammatory findings, and the patient was treated on an outpatient basis with erythromycin and an expectorant. In late November 2008, sputum and coughing were observed. Furthermore, the patient developed a fever and chest pain that increased while breathing and he visited the emergency outpatient unit of our hospital on December 1. Hypoxemia, bilateral pneumonia, and right pneumothorax were observed, and a chest tube was inserted into the right thoracic cavity. Results of an acid-fast bacteria smear from the sputum and pleural effusion were positive, and M. marinum was identified on culture. The patient was diagnosed as having a lung infection complicated by pneumothorax caused by M. marinum. The lung infection was ameliorated with clarithromycin, rifampicin and ethambutol. However, no decreased in the air leaking from the chest tube was noted and inflation of the lung was incomplete. The department of respiratory surgery therefore performed thoracoplasty and lung cerclage. Subsequently, the air leak subsided, allowing removal of the chest tube and the patient was discharged.

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