Epidemiological trends of traveler's diarrhea in Japan: An analysis of imported infectious disease registry data from 2017-2022.

Traveler's diarrhea (TD) is a global problem, and identifying the causative organisms of TD is important for adequate treatment. Therefore, this study retrospectively analyzed TD cases in patients who returned to Japan after traveling abroad to determine the causative organisms by travel region. We included patients with a final diagnosis of TD registered in the Japan Registry for Infectious Diseases from Abroad database from September 25, 2017, to September 1, 2022, from 14 medical institutions. A total of 919 patients were analyzed; the causative TD pathogen was identified in 188 cases (20%), of which 154 were caused by diarrheagenic bacteria, the most common being Campylobacter spp. (64%). A 2.2 mg/dL C-reactive protein concentration cutoff value had some predictive ability for bacterial TD (negative predictive value, 89%). Therefore, the C-reactive protein level may help rule out bacterial diarrhea and prevent unnecessary antimicrobial administration when patients cannot provide a stool specimen.

Application of MALDI-TOF MS to assess clinical characteristics, risk factors, and outcomes associated with anaerobic bloodstream infection: a retrospective observational study.

BACKGROUND: Correctly identifying anaerobic bloodstream infections (BSIs) is difficult. However, a new technique, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), enables more accurate identification and appropriate treatment. Anaerobic BSIs identified by MALDI-TOF MS were retrospectively analyzed to determine the clinical and microbiological features and patient outcomes based on the anaerobic genera or group. METHODS: Medical records of patients with anaerobic BSIs were used to conduct a single-center retrospective cohort study from January 2016 to December 2020 in Nagoya, Japan. Multivariate logistic regression analysis was performed to determine the independent risk factors for in-hospital mortality. RESULTS: Of the 215 patients with anaerobic BSIs, 31 had multiple anaerobic organisms in the blood culture, including 264 total episodes of anaerobic BSIs. Bacteroides spp. were isolated the most (n = 74), followed by gram-positive non-spore-forming bacilli (n = 57), Clostridium spp. (n = 52), gram-positive anaerobic cocci (GPAC) (n = 27), and gram-negative cocci (n = 7). The median patient age was 76 years; 56.7% were male. The most common focal infection site was intra-abdominal (36.7%). The in-hospital mortality caused by anaerobic BSIs was 21.3%, and was highest with Clostridium spp. (36.5%) and lowest with GPAC (3.7%). Age, solid tumors, and Clostridium spp. were independent risk factors for in-hospital mortality. CONCLUSIONS: We identified current anaerobic BSI trends using MALDI-TOF MS and reported that mortality in patients with anaerobic BSIs patients was highest with Clostridium spp. infections.

Epidemiological trends of imported infectious diseases in Japan: Analysis of imported 2-year infectious disease registry data.

INTRODUCTION: The epidemiology of infectious diseases in Japan remains undefined despite the increasing tourism. GeoSentinel, an epidemiological surveillance system for reporting imported infectious diseases, has only two participating facilities in Japan. Although the number of infectious diseases is reported by the National Institute of Infectious Diseases, there is no detailed clinical information about these cases. Therefore, we established J-RIDA (Japan Registry for Infectious Diseases from Abroad) to clarify the status of imported infectious diseases in Japan and provide detailed information. METHODS: J-RIDA was started as a registry of imported infectious diseases. Case registration began in October 2017. Between October 2017 and September 2019, 15 medical institutions participated in this clinical study. The registry collected information about the patient's age, sex, nationality, chief complaint, consultation date, date of onset, whether visit was made to a travel clinic before travel, blood test results (if samples were collected), travel history, and final diagnosis. RESULTS: Of the 3046 cases included in this study, 46.7% to Southeast Asia, 13.0% to Africa, 13.7% to East Asia, 11.5% to South Asia, 7.5% to Europe, 3.8% to Central and South America, 4.6% to North America, 3.9% to Oceania, and 2.8% to Central and west Asia. More than 85% of chief complaints were fever and general symptoms, gastrointestinal symptoms, respiratory symptoms, or dermatologic problems. The most common diseases were travelers' diarrhea, animal bite, upper respiratory infection, influenza, and dengue fever. CONCLUSIONS: We summarized two-year cases registered in Japan's imported infectious disease registry. These results will significantly contribute to the epidemiology in Japan.

Clinical characteristics of bloodstream infection by Parvimonas micra: retrospective case series and literature review.

BACKGROUND: Gram-positive anaerobic (GPA) bacteria inhabit different parts of the human body as commensals but can also cause bacteremia. In this retrospective observational study, we analyzed GPA bacteremia pathogens before (2013-2015) and after (2016-2018) the introduction of the matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). METHOD: We conducted a retrospective observational study by searching the microbiology database to identify all positive GPA blood cultures of patients with GPA bacteremia diagnosed using the new technique, MALDI-TOF MS, between January 1, 2016 and December 31, 2018; and using a conventional phenotypic method between January 1, 2013 and December 31, 2015 at a single tertiary center in Japan. Parvimonas micra (P. micra) (17.5%) was the second most frequently identified GPA (MALDI-TOF MS); we then retrospectively reviewed electronic medical records for 25 P. micra bacteremia cases at our hospital. We also conducted a literature review of published cases in PubMed from January 1, 1980, until December 31, 2019; 27 cases were retrieved. RESULTS: Most cases of P. micra bacteremia were identified after 2015, both, at our institute and from the literature review. They were of mostly elderly patients and had comorbid conditions (malignancies and diabetes). In our cases, laryngeal pharynx (7/25, 28%) and gastrointestinal tract (GIT; 6/25, 24%) were identified as the most likely sources of bacteremia; however, the infection source was not identified in 9 cases (36%). P. micra bacteremia were frequently associated with spondylodiscitis (29.6%), oropharyngeal infection (25.9%), intra-abdominal abscess (14.8%), infective endocarditis (11.1%), septic pulmonary emboli (11.1%), and GIT infection (11.1%) in the literature review. Almost all cases were treated successfully with antibiotics and by abscess drainage. The 30-day mortalities were 4 and 3.7% for our cases and the literature cases, respectively. CONCLUSIONS: Infection sites of P. micra are predominantly associated with GIT, oropharyngeal, vertebral spine, intra-abdominal region, pulmonary, and heart valves. Patients with P. micra bacteremia could have good prognosis following appropriate treatment.