Improvement of hand hygiene adherence among staff in long-term care facilities for elderly in Japan.

INTRODUCTION: Hand hygiene is crucial for infection control in long-term care facilities for elderly (LTCFEs), because it can be easily implemented in the low-resource settings of LTCFEs. This study investigated the actual status of hand hygiene adherence in LTCFEs, identified the factors inhibiting its appropriate implementation, and evaluated the effectiveness of a hand hygiene promotion program. METHODS: In this before-and-after study, participants were staff members (n = 142) at two LTCFEs in Gunma Prefecture, Japan. We modified the World Health Organization's "five moments for hand hygiene" and assessed participants' hand hygiene adherence rates in four situations: (1) Before touching around a resident's mucous membrane area; (2) Before medical practice or clean/aseptic procedures; (3) After body fluid exposure/risk or after touching around a resident's mucous membrane area; and (4) After touching a resident's contaminated environments. The study was divided into four phases. In Phase 1, participants self-assessed their hand hygiene adherence using a questionnaire. In Phase 2, we objectively assessed participants' pre-intervention adherence rates. In Phase 3, an intervention comprising various hand hygiene promotion measures, such as education and hands-on training on hand hygiene practices and timings, was implemented. In Phase 4, participants' post-intervention adherence rates were objectively measured. RESULTS: Although most participants reported high hand hygiene adherence rate in the self-assessment (93.1%), the pre-intervention evaluation revealed otherwise (16.8%). Participants' post-intervention adherence rates increased for all four situations (77.3%). CONCLUSION: The intervention program helped increase participants' hand hygiene adherence rates, indicating its effectiveness. Similar interventions in other LTCFEs may also improve adherence rates.

Impact of infectious disease consultation on patients with Staphylococcus aureus bacteremia at a Japanese tertiary hospital: A retrospective observational study.

Several studies across various countries have shown the benefit of infectious disease consultation in patients with Staphylococcus aureus bacteremia (SAB). However, the effect of such consultation services in patients with SAB in Japan remains unknown. Accordingly, we aimed to examine the effectiveness of infectious disease consultation in SAB patients at an accredited hospital in Japan. We hypothesized that infectious disease consultation in SAB patients is associated with lower in-hospital mortality. We identified patients with SAB between January 2011 and January 2014. SAB was defined as the presence of at least one set of positive blood culture samples. The outcomes of patients who did and did not receive bedside infectious disease consultation were compared. The primary outcome was in-hospital mortality. We identified 183 patients with SAB. Eighty-seven patients (48%) received infectious disease consultation services, while 96 (52%) did not. There were no significant differences in in-hospital mortality between the infectious disease consultation and control groups (15.0% vs. 23.0%, p = 0.20). Logistic regression analysis showed that bedside infectious disease consultation (odds ratio, 0.23; 95% confidence interval, 0.08-0.69; p = 0.01) was independently associated with lower in-hospital mortality. In conclusion, bedside infectious disease consultation may help reduce the in-hospital mortality in patients with SAB in Japan.

Histological evidence for the cardiac safety of high-dose pegylated liposomal doxorubicin in a patient with HIV-associated Kaposi sarcoma: a case report and literature review.

BACKGROUND: Pegylated liposomal doxorubicin plays an important role in the treatment of patients with severe refractory human immunodeficiency virus (HIV)-associated Kaposi sarcoma (KS). High cumulative doses of conventional doxorubicin exceeding 500 mg/m2 are known to cause cardiac toxicity. However, the safe cumulative dose of pegylated liposomal doxorubicin is unclear. CASE PRESENTATION: A 40-year-old Japanese man with HIV infection presented with pain, edema, and multiple skin nodules on both legs which worsened over several months. He was diagnosed with HIV-associated KS. He received long-term pegylated liposomal doxorubicin combined with antiretroviral therapy for advanced, progressive KS. The cumulative dose of pegylated liposomal doxorubicin reached 980 mg/m2. The patient's left ventricular ejection fraction remained unchanged from baseline during treatment. After he died as a result of cachexia and wasting, caused by recurrent sepsis and advanced KS, an autopsy specimen of his heart revealed little or no evidence of histological cardiac damage. We also conducted a literature review focusing on histological changes of the myocardium in patients treated with a cumulative dose of pegylated liposomal doxorubicin exceeding 500 mg/m2. CONCLUSIONS: This case report and literature review suggest that high (> 500 mg/m2) cumulative doses of pegylated liposomal doxorubicin may be used without significant histological/clinical cardiac toxicity in patients with HIV-associated KS.

Azithromycin plus ß-lactam versus levofloxacin plus ß-lactam for severe community-acquired pneumonia: A retrospective nationwide database analysis.

Previous studies showed potential benefits of macrolide combined with ß-lactam for severe community-acquired pneumonia (CAP). However, it remains inconclusive whether macrolide plus ß-lactam is superior to respiratory fluoroquinolone plus ß-lactam for patients with severe CAP. Using a nationwide inpatient database in Japan, we performed propensity score matching and inverse probability of treatment weighting (IPTW) to compare 28-day mortality and in-hospital mortality between azithromycin plus ß-lactam and levofloxacin plus ß-lactam for severe CAP patients admitted to hospital between July 2010 and March 2015. We identified 1,999 patients with severe pneumonia who received azithromycin plus ß-lactam (n = 840) or levofloxacin plus ß-lactam (n = 1,159) within 2 days after admission. Five-hundred sixty propensity score-matched pairs showed no significant differences between azithromycin plus ß-lactam and levofloxacin plus ß-lactam in 28-day mortality and in-hospital mortality (19.3% vs. 20.7%, p = 0.601 and 24.8% vs. 26.8%, p = 0.495, respectively). IPTW analysis also showed no significant differences between azithromycin plus ß-lactam and levofloxacin plus ß-lactam in 28-day mortality (risk difference, -3.5% [95% confidence interval, -8.8% to 1.7%] and in-hospital mortality (risk difference, -3.6%; 95% confidence interval, -9.4% to 2.1%). In conclusion, there were no significant differences in 28-day mortality and in-hospital mortality between azithromycin plus ß-lactam and levofloxacin plus ß-lactam for severe CAP patients.

False-positive elevation of 1,3-beta-D-glucan caused by continuous administration of penicillin G.

The 1,3-beta-D-Glucan (BDG) assay is widely used for the diagnosis of fungal infections, especially in patients with hematologic malignancies. Some antimicrobials have been reported to cause false-positive results for BDG, but there has been no report on the effect of penicillin G (PCG) on BDG levels. We experienced a patient who developed false-positive BDG elevation during the administration of PCG for osteomyelitis due to Streptococcus pneumoniae infection. The serum BDG level increased up to 81.0 pg/ml during the continuous administration of PCG at 24 million units per day. However, chest and paranasal CT scan showed no evidence of fungal infection. The BDG level decreased to 38.0 pg/ml at 14 hours after the discontinuation of PCG. The amount of BDG in one vial of PCG inferred from these serum BDG levels is very similar to the actual BDG concentration in a vial of PCG. Therefore, during the administration of PCG, elevated BDG levels should be interpreted with caution, as they may be false-positive results.

Mycobacterium mageritense Parotitis in an Immunocompetent Adult.

Mycobacterium mageritense, a rapidly growing mycobacterium, is a rare clinical pathogen. Furthermore, parotitis due to non-tuberculosis mycobacterium is very rare in adults. Herein, we report the first case of M. mageritense parotitis in an immunocompetent adult. A 40-year-old man presented with swelling in a left parotid lesion. He was diagnosed with parotitis. The culture from the parotid abscess grew M. mageritense. He was unsuccessfully treated with levofloxacin monotherapy. Trimethoprim-sulfamethoxazole was added, leading to some clinical response; however, the erythema persisted despite 14 months of antibiotic therapy. Subsequently, the skin lesion was surgically removed. The antibiotic treatment was ceased a week after surgery as the postoperative course was uneventful and the lesion had improved. No recurrence was noted at 7 months after surgery. Although extremely rare, M. mageritense can cause parotitis in immunocompetent adults, and may not be sufficiently treated with antibiotics alone.

Peripherally inserted central catheter-related bloodstream infection due to Tsukamurella pulmonis: a case report and literature review.

BACKGROUND: Tsukamurella pulmonis is an aerobic gram-positive and rod-shaped organism that causes central catheter-related bloodstream infections in immunocompromised hosts. However, peripherally inserted central catheter (PICC)-related bloodstream infections due to this organism have not been reported. CASE PRESENTATION: We describe a case of a 48-year-old man with acquired immunodeficiency syndrome and diffuse large B cell lymphoma who received five courses of chemotherapy including rituximab , cyclophosphamide , doxorubicin hydrochloride , vincristine , and prednisone via a PICC. Five days after the last chemotherapy course, he presented with a high fever and shaking chills. His absolute neutrophil count was 4200/µL. Cultures obtained from blood and PICC culture revealed T. pulmonis. The colony count of T. pulmonis grown from PICC culture was 103 colony-forming units. Therefore, he was diagnosed with T. pulmonis bacteremia resulting from PICC-related bloodstream infection. The patient's condition improved and he became afebrile within 48 h after intravenous administration of cefozopran hydrochloride, which is a fourth generation cephalosporin. CONCLUSIONS: PICCs can be associated with T. pulmonis bacteremia, and fourth generation cephalosporins may be effective treatment.

Cutaneous invasive aspergillosis in a patient with glioblastoma receiving long-term temozolomide and corticosteroid therapy.

Glioblastoma is an aggressive brain tumor that requires multidisciplinary treatment including adjuvant radiotherapy, chemotherapy, and adjunct corticosteroids. Temozolomide is a commonly used chemotherapy drug and frequently causes lymphocytopenia. We describe the case of a 67-year-old woman with cutaneous invasive aspergillosis who had received long-term temozolomide and corticosteroid therapy for glioblastoma. She presented with multiple indurations, erythema, and purpura, some of which produced purulent discharge, in the anterior abdomen. Extensive intra- or inter-muscular abscesses of the right anterior abdominal wall were also observed. Her absolute lymphocyte counts were 156/µL on admission. Cultures obtained from the wound yielded Aspergillus fumigatus. She was diagnosed with secondary cutaneous invasive aspergillosis, which likely resulted from hematogenous dissemination. Although rare, this case illustrates that temozolomide-induced lymphocytopenia, especially in cases of concomitant corticosteroid use, can be associated with severe invasive aspergillosis.

Contamination of healthcare workers' hands with bacterial spores.

Clostridium species and Bacillus spp. are spore-forming bacteria that cause hospital infections. The spores from these bacteria are transmitted from patient to patient via healthcare workers' hands. Although alcohol-based hand rubbing is an important hand hygiene practice, it is ineffective against bacterial spores. Therefore, healthcare workers should wash their hands with soap when they are contaminated with spores. However, the extent of health care worker hand contamination remains unclear. The aim of this study is to determine the level of bacterial spore contamination on healthcare workers' hands. The hands of 71 healthcare workers were evaluated for bacterial spore contamination. Spores attached to subject's hands were quantitatively examined after 9 working hours. The relationship between bacterial spore contamination and hand hygiene behaviors was also analyzed. Bacterial spores were detected on the hands of 54 subjects (76.1%). The mean number of spores detected was 468.3 CFU/hand (maximum: 3300 CFU/hand). Thirty-seven (52.1%) and 36 (50.7%) subjects were contaminated with Bacillus subtilis and Bacillus cereus, respectively. Nineteen subjects (26.8%) were contaminated with both Bacillus species. Clostridium difficile was detected on only one subject's hands. There was a significant negative correlation between the hand contamination level and the frequency of handwashing (r = -0.44, P < 0.01) and a significant positive correlation between the hand contamination level and the elapsed time since last handwashing (r = 0.34, P < 0.01). Healthcare workers' hands may be frequently contaminated with bacterial spores due to insufficient handwashing during daily patient care.

Temporal Trend of the SARS-CoV-2 Omicron Variant and RSV in the Nasal Cavity and Accuracy of the Newly Developed Antigen-Detecting Rapid Diagnostic Test.

The aim of this work is to analyze the viral titers of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and respiratory syncytial virus (RSV) at the anterior nasal site (ANS) and nasopharyngeal site (NS), evaluate their virological dynamics, and validate the usefulness of a newly developed two-antigen-detecting rapid antigen diagnostic test (Ag-RDT) that simultaneously detects SARS-CoV-2 and RSV using clinical specimens. This study included 195 asymptomatic to severely ill patients. Overall, 668 specimens were collected simultaneously from the ANS and NS. The cycle threshold (Ct) values calculated from real-time polymerase chain reaction were used to analyze temporal changes in viral load and evaluate the sensitivity and specificity of the Ag-RDT. The mean Ct values for SARS-CoV-2-positive, ANS, and NS specimens were 28.8, 28.9, and 28.7, respectively. The mean Ct values for RSV-positive, ANS, and NS specimens were 28.7, 28.8, and 28.6, respectively. SARS-CoV-2 and RSV showed the same trend in viral load, although the viral load of NS was higher than that of ANS. The sensitivity and specificity of the newly developed Ag-RDT were excellent in specimens collected up to 10 days after the onset of SARS-CoV-2 infection and up to 6 days after the onset of RSV infection.

[Clinical evaluation of inpatients with tuberculosis diagnosed after admission--comparison of characteristics of patients diagnosed with and without the acid-fast bacillus test].

PURPOSE: To evaluate the clinical characteristics of patients in whom tuberculosis was not suspected before admission but was diagnosed after admission. METHODS: We enrolled 39 inpatients who were diagnosed with tuberculosis between April 2007 and March 2011 at Jichi Medical University Hospital. The patients were divided into 2 groups as follows: those who underwent a preadmission acid-fast bacillus (AFB) test (AFB group) and those who did not (non-AFB group). We retrospectively evaluated the clinical characteristics of these 2 groups of patients. RESULTS: A total of 22 patients and 17 patients comprised the non-AFB and AFB groups, respectively. The prevalence rates of malignancy (9 vs. 2 patients, p = 0.04), extrapulmonary tuberculosis without pulmonary tuberculosis (9 vs. 2 patients, p = 0.04), and smear-negative tuberculosis (16 vs. 7 patients, p = 0.04) were higher in the non-AFB group than in the AFB group. In contrast, the computed tomographic findings of the patients with pulmonary tuberculosis revealed that compared with the AFB group, the non-AFB group had less consolidation (2 vs. 11 patients, p < 0.01) and fewer cavitary lesions (0 vs. 6 patients, p < 0.01) and more nodular lesions (8 vs. 2 patients, p < 0.01). We then divided the inpatients into groups with and without malignancy and compared their clinical characteristics. The mean interval from admission to diagnosis of tuberculosis was significantly longer in the patients with malignancy as an underlying disease than in those without malignancy (23.5 vs. 10.5 days; p < 0.01). CONCLUSION: Malignancy was the most frequent underlying disease in the tuberculosis inpatients in the non-AFB group and could be the reason for the delayed diagnosis of tuberculosis.

Syncope after COVID-19 Vaccination in a Young Man with Unmasking Brugada Syndrome.

A 23-year-old man with no significant medical history was rushed to a hospital due to transient loss of consciousness with incontinence. The patient had developed a fever after his second dose of coronavirus disease 2019 (COVID-19) vaccine, and the patient was found groaning in bed approximately 40 hours after the vaccination in the early morning. The patient was diagnosed with Brugada syndrome (BrS) based on a drug-provocation test. His father had been diagnosed with BrS and died suddenly at 51 years of age. Young adults with a family history of BrS should be cautioned about fever following COVID-19 vaccination.

Serum 25-hydroxycholesterol levels are increased in patients with coronavirus disease 2019.

BACKGROUND: 25-hydroxycholesterol (25HC), produced by cholesterol 25-hydroxylase (CH25H) in macrophages, has been reported to inhibit the replication of viral pathogens such as severe acute respiratory syndrome coronavirus-2. Also, CH25H expression in macrophages is robustly induced by interferons (IFNs). OBJECTIVE: To better understand the serum level increase of 25HC in coronavirus disease 2019 (COVID-19) and how it relates to the clinical picture. METHODS: We measured the serum levels of 25HC and five other oxysterols in 17 hospitalized COVID-19 patients. RESULTS: On admission, 25HC and 27-hydroxycholesterol (27HC) serum levels were elevated; however, 7-ketocholesterol (7KC) levels were lower in patients with COVID-19 than in the healthy controls. There was no significant correlation between 25HC serum levels and disease severity markers, such as interferon-gamma (IFN-γ) and interleukin 6. Dexamethasone effectively suppressed cholesterol 25-hydroxylase (CH25H) mRNA expression in RAW 264.7 cells, a murine leukemia macrophage cell line, with or without lipopolysaccharide or IFNs; therefore, it might mitigate the increasing effects of COVID-19 on the serum levels of 25HC. CONCLUSIONS: Our results highlighted that 25HC could be used as a unique biomarker in severe COVID-19 and a potential therapeutic candidate for detecting the severity of COVID-19 and other infectious diseases.

Effect of Inhaled Ciclesonide in Non-Critically Ill Hospitalized Patients With Coronavirus Disease 2019: A Multicenter Observational Study in Japan.

Background: Coronavirus disease 2019 (COVID-19) is an ongoing global pandemic. Although systemic steroids play an important role in treating patients with severe COVID-19, the role of inhaled corticosteroids in non-critically ill, hospitalized patients with COVID-19 remains unclear. Methods: We analyzed findings in non-critically ill, hospitalized patients with COVID-19 who were >18 years old and were admitted to 64 Japanese hospitals between January and September 2020. We performed propensity score matching analysis to evaluate 28-day and in-hospital mortality rates with or without inhaled ciclesonide within 2 days of admission. Sensitivity analyses using inverse probability weighting analysis, and generalized estimating equation method were also performed. Results: Eligible patients (n = 3638) were divided into ciclesonide (n = 290) and control (n = 3, 393) groups. The 1-to-4 propensity score matching analysis included 271 ciclesonide users and 1084 nonusers. There were no significant differences between the 2 groups for 28-day (3.3% vs 2.3%; risk difference, 1.0% [95% confidence interval, -1.2 to 3.3]) or in-hospital (4.8% vs 2.6%; risk difference, 2.2 [-.5 to 4.9]) mortality rates. The sensitivity analysis showed similar outcomes. Conclusions: From this multicenter observational study in Japan, inhaled ciclesonide did not decrease 28-day or in-hospital mortality rates in non-critically ill, hospitalized patients with COVID-19. Future large, multinational, randomized trials are required to confirm our results.

[Isolation precautions--transmission-based precautions].

There are two tiers of precautions to prevent transmission of infectious agents, standard precautions and transmission-based precautions. Standard precautions are intended to be applied to the care of all patients in all healthcare settings, regardless of the suspected or confirmed presence of an infectious agent. Transmission-based precautions are for patients who are known or suspected to be infected or colonized with infectious agents, which require additional control measures to effectively prevent transmission. Transmission-based precautions are used empirically, according to the likely etiologic agents at the time, and then modified when the pathogen is identified or a transmissible infectious etiology is ruled out. Implementation of preventive measures should be based on infection control risk assessment.

Additional effect of azithromycin over ß-lactam alone for severe community-acquired pneumonia-associated acute respiratory distress syndrome: a retrospective cohort study.

BACKGROUND: Community-acquired pneumonia (CAP) is the most common cause of acute respiratory distress syndrome (ARDS). Although previous studies have suggested that macrolide therapy is beneficial for ARDS, its benefit for severe CAP-associated ARDS remains uncertain. Previous studies were limited in that they had a small sample size and included patients with non-pulmonary ARDS and those with pulmonary ARDS. This study aimed to investigate the additional effect of azithromycin when used with ß-lactam compared with the effect of ß-lactam alone in mechanically ventilated patients with CAP-associated ARDS. METHODS: We identified mechanically ventilated patients with CAP-associated ARDS between July 2010 and March 2015 using data in the Diagnosis Procedure Combination database, a Japanese nationwide inpatient database. We performed propensity score matching analysis to assess 28-day mortality and in-hospital mortality in mechanically ventilated patients with CAP-associated ARDS who received ß-lactam with and without azithromycin within hospital 2 days after admission. The inverse probability of treatment weighting analysis was also conducted. RESULTS: Eligible patients (n = 1257) were divided into the azithromycin group (n = 226) and the control group (n = 1031). The one-to-four propensity score matching analysis included 139 azithromycin users and 556 non-users. No significant difference was observed between the groups with respect to 28-day mortality (34.5% vs. 37.6%, p = 0.556) or in-hospital mortality (46.0% vs. 49.1%, p = 0.569). The inverse probability of treatment weighting analysis showed similar results. CONCLUSIONS: Compared with treatment with ß-lactam alone, treatment with azithromycin plus ß-lactam had no significant additional effect on 28-day mortality or in-hospital mortality in mechanically ventilated patients with CAP-associated ARDS. To the best of our knowledge, this study is the first to determine the effect of azithromycin in mechanically ventilated patients with CAP-associated ARDS.

Diagnostic accuracy of a novel SARS CoV-2 rapid antigen test and usefulness of specimens collected from the anterior nasal cavity.

OBJECTIVES: We aimed to validate a newly developed antigen-detecting rapid diagnostic test (Ag-RDT) for SARS-CoV-2 using anterior nasal specimens. METHODS: Between February 12 and September 30, 2021, 16 patients (age range, <1 month-76 years) were enrolled, and samples were collected simultaneously from anterior nasal and nasopharyngeal sites continuously during hospitalization. The primary end points were the diagnostic accuracy of the Ag-RDT and utility of anterior nasal specimens. RESULTS: In total, 226 sets of paired samples were obtained. In 88.2% of specimens, the viral load was high at the nasopharyngeal site. The mean cycle threshold values for the anterior nasal and nasopharyngeal sites were 32.4 and 29.9, respectively. Using the real-time polymerase chain reaction results as a reference, the Ag-RDT showed a 100% sensitivity up to day 6 of the illness, using specimens with moderate or high viral load (cycle threshold <30) from either site. From day 7, the sensitivity was 70.4-90.6% and 83.9-84.6% for the anterior nasal and nasopharyngeal sites, respectively. The specificity remained at 100%. CONCLUSION: Our novel Ag-RDT meets the World Health Organization criteria and provides stable sensitivity and specificity and accurate results with anterior nasal specimens.

Low prevalence of SARS-CoV-2 specific antibodies among endoscopists and their assistants in a university hospital in Tochigi prefecture-A single-center study.

Objectives: Gastrointestinal endoscopic procedures have a risk to transmit severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) through aerosols. Little information is available on the seroprevalence of SARS-CoV-2 antibodies among healthcare workers (HCWs) in endoscopy units. Thus, the seroprevalence was examined in HCWs who do and do not participate in gastrointestinal endoscopy. Methods: A total of 382 HCWs at Jichi Medical University Hospital were enrolled in this study through March 2021. Among 382 HCWs, 63 are in the endoscopy unit. Serum antibody levels against SARS-CoV-2 were determined by immunochromatography, chemiluminescent immunoassay (CLIA), electric CLIA (ECLIA), and chemiluminescence microparticle immunoassay (CMIA). HCWs in the endoscopy unit underwent testing up to three times. We defined antibody-positive as when at least one test was positive. Results: The seroprevalence of SARS-CoV-2 antibodies in 63 HCWs in the endoscopy unit was 0%-1.9%, 0%-1.7%, and 0%-1.7% during the first (Ap-May 2020), second (Jun-Nov 2020), and third intervals (Dec 2020-Mar 2021), respectively. This seroprevalence was comparable to that of other HCWs not involved with gastrointestinal endoscopy. Two HCWs in the endoscopy unit were positive for antibodies: one was ECLIA-positive and the another was CMIA-positive. The ECLIA-positive HCW was PCR negative and converted to negative for the second and third tests. Another HCW was CMIA-positive at all three evaluations and the titers were unchanged. No HCWs in the endoscopy unit contracted a SARS-CoV-2 infection. Conclusions: The seroprevalence of SARS-CoV-2 antibodies was low among HCWs in the endoscopy unit through March 2021 (UMIN000039997).

[A case of disseminated gonococcal infection without typical skin rash].

Few case reports have been published on disseminated gonococcal infection in Japan. We report such a non-HIV case without typical skin rash. A 49-year-old Japanese man living in Thailand on business was seen for fever and multiple arthralgia after returning to Japan. Given the travel history, differential diagnoses included endemic viral infection such as human immunodeficiency virus (HIV), dengue fever, and chikungunya. Diagnosis was based on right-knee arthrocentesis, and synovial fluid culture followed by Neisseria gonorrhoeae polymerase chain reaction (PCR). The isolated strain was sensitive to penicillin. The man was treated with intravenous ceftriaxone and oral levofloxacin. Disseminated gonococcal infection should thus be considered when examining those with classical polyarthralgia symptoms even without a typical skin rash.

Carriage Rate and Characteristics of Neisseria meningitidis among Dormitory Students.

In Japan, several meningococcal disease outbreaks have recently been reported among adolescent dormitory residents of schools. However, little is known about meningococcal carriage dynamics in healthy individuals. The purpose of this study was to investigate the carriage rate over time and characteristics of Neisseria meningitidis strains among dormitory students. The survey was conducted twice between November 2018 and January 2019 for first- to third-year students (N = 376) in a medical school dormitory. The two surveys yielded carriage rates of 0.4% (one positive among 257 students) and 2.1% (two positives among 97 students, including 90 re-participants). No transmission or persistence of a specific strain was observed during the two months. A limited number of students had a history of potential risk behaviors for carriage, such as smoking (3.0% [6/202] aged ≥20 years and 5.2% [4/77] aged ≥20 years, respectively) and attending parties more than once a week (4.3% [11/257] and 2.1% [2/97], respectively). Two isolates were unencapsulated, consistent with asymptomatic participants.