The five-year trends in antibiotic prescription by dentists and antibiotic prophylaxis for tooth extraction: a region-wide claims study in Japan.

BACKGROUND: Antimicrobial stewardship in dentistry and antibiotic prophylaxis for tooth extraction have been areas of concern in Japan, with limited research available. METHODS: This cross-sectional study utilized the regional health insurance claims database in Japan to examine antibiotic prescription trends by dentists, including antibiotic regimens, timing of prescription, and days of supply for prophylactic antibiotic use during tooth extraction. Antibiotic prophylaxis for patients with prosthetic heart valves was also investigated. FINDINGS: Antibiotic prescriptions by dentists decreased by 7% in 2019 compared to those in 2015, with third-generation cephalosporins still accounting for 48.5% in 2019. Amoxicillin prescription increased 3.9 times in 2019, although it only accounted for 8.4% of all antibiotic prescriptions. In 2019, amoxicillin was prescribed for 17.1% of all prophylactic antibiotics associated with tooth extraction, and 80% of prophylactic antibiotics were prescribed for 3 days or more, with 85% prescribed on the day of the procedure. However, only 60-70% of patients with prosthetic heart valves received antibiotic prophylaxis. INTERPRETATION: Despite the increasing trend after the implementation of the National Action Plan on antimicrobial resistance, the proportion of amoxicillin prescriptions in dentistry remains low. Antimicrobial stewardship issues related to long-term prescription and timing of administration of prophylactic antibiotics for tooth extraction should be addressed. Dentists must recognize the risks associated with high-risk patients with prosthetic heart valves who require antibiotic prophylaxis, and physicians providing valve replacement therapy should inform patients of the requirement for prophylaxis before invasive dental procedures.

Disseminated Mycolicibacter arupensis and Mycobacterium avium co-infection in a patient with anti-interferon-γ neutralizing autoantibody-associated immunodeficiency syndrome.

BACKGROUND: Disseminated infections of Mycolicibacter arupensis, a slowly growing nontuberculous mycobacteria (NTM) which causes synovitis, osteomyelitis, or pulmonary infections have rarely been reported. We report a case of disseminated M. arupensis and Mycobacterium avium co-infection in a patient with anti-interferon (IFN)-γ neutralizing autoantibody-associated immunodeficiency syndrome. CASE PRESENTATION: A 68-year-old Japanese male without human immunodeficiency virus infection was referred with complaints of persistent low-grade fever, arthralgia of the upper limbs, and weight loss of 10 kg. Cervical and mediastinal lymphadenopathies as well as a nodular opacity in the right lung were detected, and biopsy specimens of the cervical lymph node yielded M. arupensis without evidence of malignant cells. M. arupensis was also detected in sputum and peripheral blood. Computed tomography (CT) revealed deterioration of the right supraclavicular lymphadenopathy with internal necrosis and multiple low-density splenic lesions. Bone marrow and aspirates from the cervical lymph node collected at initiation of treatment yielded M. avium. The presence of anti-IFN-γ neutralizing autoantibodies was detected, leading to a diagnosis of co-infection of M. arupensis and M. avium with anti-IFN-γ neutralizing autoantibody-associated immunodeficiency syndrome. Post initiation of treatment with clarithromycin, ethambutol, and rifabutin, his fever declined, and his polyarthritis resolved. He developed disseminated varicella zoster during treatment; however, a follow-up CT scan six months after treatment revealed improvement of the lymphadenopathies, consolidation in the right lung, and splenic lesions. CONCLUSION: This is the first report of disseminated M. arupensis and M. avium co-infection in a patient with anti-IFN-γ neutralizing autoantibody-associated immunodeficiency syndrome.

Collision tumor of primary malignant lymphoma and adenocarcinoma in the colon: report of a case.

This report presents the case of a 62-year-old man with a collision tumor of primary malignant lymphoma and adenocarcinoma in the cecum. All regional mesenteric lymph nodes that were removed surgically were found to be occupied by lymphoma cells and no lymph nodes contained any cancer cells, although the primary carcinomas did exhibit lymphatic invasion. Malignant lymphoma was also seen in the duodenum. Systemic chemotherapy was administered for the malignant lymphoma, and a complete response was thus obtained. However, just after chemotherapy multiple liver metastases of adenocarcinoma emerged, and chemotherapy against adenocarcinoma was therefore continued. The occurrence of synchronous lymphoma and adenocarcinoma of the colorectum is rare. Furthermore, collisions of these different entities are also extremely unusual; so far only five such case reports have been published. The accurate clinical determination of the dominant tumor and a close follow-up is required for proper treatment in these cases.