[Outbreak of extensively drug-resistant pulmonary tuberculosis in a hemodialysis facility].

We experienced an outbreak of extensively drug-resistant pulmonary tuberculosis (XDR-TB) in a hemodialysis facility. The primary case involved a 51-year-old male hemodialysis patient, with a history of treatment for Mycobacterium tuberculosis infection seven years previously. There was no drug resistance, and the patient completely recovered after undergoing treatment with isoniazid (INH), rifampicin (RFP) and ethambutol (EB). He was admitted to another hospital due to a recurrence of pulmonary tuberculosis in June 2006. At first, he was treated with HRS [INH, RFP and streptomycin (SM)]; however, the drug regimen was changed to INH, EB, levofloxacin (LVFX) and kanamycin (KM) in August following the results of a drug susceptibility test. Although the patient was receiving outpatient tuberculous therapy, he was readmitted in June 2007 due to relapse and conversion of a sputum culture to positive status. Additionally, the XDR-TB organism was identified. Following these events, five staff members of the hemodialysis facility and a member of the patient's family were diagnosed with XDR-TB infection. The staffs who were infected with XDR-TB had worked in the same dialysis room, drug resistance was found in all cases and drug resistant gene mutations were found in three cases; therefore, we considered this to be an outbreak. As XDR-TB infection was suspected in all cases, no patients took drugs to treat latent tuberculosis infection (LTBI). Regarding the causes of the outbreak, the first is the delay of four months in making a diagnosis of re-exacerbation of tuberculosis. Second, in Case 2, the patient developed laryngeal and tracheobronchial tuberculosis after first being diagnosed with asthma, and the tuberculosis diagnosis was delayed. Third, the sputum smear of Case 2 was strongly positive. There is only one previously reported outbreak of XDR-TB in Japan; therefore, we consider this outbreak to be educational.

[A case of hard metal lung disease in a man who worked as an iron grinder].

The patient was a man who had suffered from repeated pneumothoraces since August 2003, when he was 16 years old. A right pneumothorax was observed at age 21 years, in April 2008. At the same time, a dry cough began to appear and diffuse small nodular shadows in both lung fields were found on a chest X-ray film. Due to worsening symptoms and the chest X-ray findings, a transbronchial lung biopsy was performed in September 2008. Pathological examination showed mural type organization, and large numbers of multinucleated giant cells that were engulfing nucleated cells and had black pigment in their cytoplasm. Giant cell interstitial pneumonia and hard metal lung disease (HMLD) were suspected because of the patient's occupational history as a metal grinder, which included the use of a hard metal tool for three years since August 2005. In an elementary analysis using an electron probe microanalyzer, tungsten was detected in resected lung tissue obtained in April 2008 which confirmed the diagnosis. His symptoms improved after the initiation of corticosteroid therapy, which continued but with a gradual decrease in the dose. In this case, HMLD developed over a relatively short period despite the low level of dust dispersal of a hard-metal tool, perhaps because of a hypersensitivity of the patient to hard metal.