Factors associated with household transmission of SARS-CoV-2 omicron variant to health care workers: A retrospective cohort study.

AIM: The aim of this study was to determine the risk factors for household transmission of the omicron variant of SARS-CoV-2. BACKGROUND: The household infection rate has been reported to be higher for the omicron variant than for non-omicron variants of SARS-CoV-2. Determination of the risk factors for household transmission of the omicron variant is therefore important. DESIGN: A Retrospective Cohort Study was conducted. METHODS: When family members of health care workers (HCWs) were found to be infected with SARS-CoV-2, the HCWs had to receive two nucleic acid amplification tests for SARS-CoV-2: immediately after and 5 to 10 days after the onset of COVID-19 in the family members. Risk factors of household transmission were analysed by comparing cases (HCWs infected with SARS-CoV-2) and controls (HCWs not infected with SARS-CoV-2) using multivariable analysis. RESULTS: Unvaccinated status (OR: 3.97), age of index cases (≤6 years) (OR: 1.94) and staying at home with index cases (OR: 10.18) were risk factors for household transmission. CONCLUSION: If there is a strong desire to avoid household infection, family members infected with SARS-CoV-2 should live separately during the period of viral shedding.

Risk factors of multidrug-resistant pyogenic spondylitis in thoraco-lumbar spine: A retrospective study of 122 cases.

BACKGROUND: The number of spinal infections has been increasing in developed countries due to the increase of aged or immunosuppressed patients. Spondylitis caused by multidrug-resistant (MDR) bacterial infection often become intractable and require long-term antibiotic therapy and multiple surgeries. Therefore, it is of great importance to understand risk factors for MDR spinal infections. The aim of this study was to elucidate the risk factors for MDR bacterial spondylitis. METHODS: A total of 122 patients (82 men, 40 women; average age: 63.8 y) with thoracic/lumbar spondylitis who underwent posterolateral full-endoscopic debridement and irrigation were included. The organisms detected by this endoscopic procedure were investigated, and the incidence and risk factors for MDR bacterial infection were retrospectively analyzed. RESULTS: Cultures of specimens obtained by endoscopic procedures were positive in 78 patients (63.9%). Among 68 isolated bacteria, MDR bacteria accounted for 47.1%. Multivariate analysis showed that significant risk factors for MDR bacterial infection included autoimmune connective tissue disease (P = 0.03) and central venous catheter (P = 0.02). The incidence of MDR bacteria in patients who were administered a broad-spectrum antibiotic for more than 1 month preoperatively was 64.0%, which was significantly higher than in patients who were administered a broad-spectrum antibiotic for less than 1 month and patients who were administered a narrow-spectrum antibiotic (P < 0.01, P < 0.01, respectively). CONCLUSIONS: The significant risk factors for MDR bacterial spondylitis included immunosuppressed conditions, such as autoimmune connective tissue disease, presence of central venous catheter, and longer administration periods of a broad-spectrum antibiotic. In patients with pyogenic spondylitis who could not be controlled with previous antibiotics and whose result of culture was negative, administration of anti-MRSA antibiotics would be considered when they have the risk factors identified in this study.

Clinical and virological outcomes with baloxavir compared with oseltamivir in pediatric patients aged 6 to < 12 years with influenza: an open-label, randomized, active-controlled trial protocol.

BACKGROUND: Children with influenza virus infections are prone to complications and are common sources of influenza transmission. Baloxavir marboxil inhibits cap-dependent endonuclease and was approved for influenza treatment in adolescent, adult, and pediatric patients in Japan. The miniSTONE-2 study included pediatric patients with influenza (1 to < 12 years) and demonstrated similar median times to alleviation of signs and symptoms of influenza with a single dose of baloxavir granules (weight < 20 kg: 2 mg/kg, ≥ 20 kg: 40 mg) and oseltamivir. Although the baloxavir dose in miniSTONE-2 was higher than the Japanese-approved dose, baloxavir exposure in miniSTONE-2 was similar to Japanese pediatric patients who receive the Japanese-approved dose. This study will be the first randomized active-controlled study in pediatric patients with influenza using the Japanese-approved dose of baloxavir. METHODS: This is a multicenter, open-label, randomized, active-controlled trial in which 200 Japanese subjects aged 6 to < 12 years with influenza virus infection are randomly allocated (2:1) to a single dose of baloxavir at the approved dose in Japan (weight ≥ 10 to < 20 kg: 10 mg, ≥ 20 to < 40 kg: 20 mg, ≥ 40 kg: 40 mg) or oseltamivir twice daily for 5 days. The primary clinical endpoint is the time to illness alleviation of influenza, from administration of baloxavir or oseltamivir until the following criteria were met and sustained for at least 21.5 h (24 h-10%): cough and nasal discharge/nasal congestion rated as absent or mild axillary body temperature < 37.5 °C. The primary analysis population is the intention-to-treat infected population, which includes all pediatric subjects who receive at least one dose of study drug and have confirmed influenza virus infection by reverse transcription-polymerase chain reaction. The safety population includes all subjects who receive at least one dose of study drug. DISCUSSION: No comparative studies have been conducted to confirm the efficacy and safety of baloxavir versus a comparator in pediatric patients with influenza infection in Japan. The outcomes from this trial will provide evidence on the efficacy and safety of baloxavir as an antiviral treatment option for Japanese pediatric patients with influenza infection. Trial registration Japan Registry of Clinical Trials: jRCTs011200011. Registered November 2020. ( https://rctportal.niph.go.jp/en/ ).

Three-day regimen of oseltamivir for post-exposure prophylaxis of influenza in hospital wards: a study protocol for a prospective, multi-center, single-arm trial.

BACKGROUND: In a previous retrospective observational study, a 3-day regimen of oseltamivir as post-exposure prophylaxis (PEP) for preventing transmission of influenza in wards was shown to be comparable to 7- to 10-day regimens provided index cases were immediately separated from close contacts. In order to confirm the efficacy of a 3-day regimen, we started to conduct a prospective, multi-center, single-arm trial. METHODS: This study is a prospective, multi-center, single-arm study designed by the Sectional Meeting of Clinical Study, Japan Infection Prevention and Control Conference for National and Public University Hospitals. Index patients with influenza are prescribed a neuraminidase inhibitor and are discharged immediately or transferred to isolation rooms. The close contacts are given oseltamivir as 75 mg capsules once daily for adults or 2 mg/kg (maximum of 75 mg) once daily for children for 3 days as PEP. All close contacts are monitored for development of influenza for 7 days after starting PEP. DISCUSSION: A 3-day regimen of oseltamivir as PEP has advantages over 7- to 10-day regimens in terms of costs, medication adherence and adverse effects. Trial registration The Institutional Review Board of Hokkaido University Hospital for Clinical Research, 015-0518, registered on November 11, 2016. UMIN Clinical Trials Registry, UMIN000024458, disclosed on October 31, 2016. https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000027881 . Japan Registry of Clinical Trials, jRCTs011180015, disclosed on March 14, 2019. https://jrct.niph.go.jp/latest-detail/jRCTs011180015.

Evaluation of a Novel Immunochromatographic Assay Using Monoclonal Antibodies against the Matrix Protein of Human Metapneumovirus.

BACKGROUND: The aim of this study was to determine the sensitivity and specificity of a novel immunochromatographic (IC) assay (APD1806) using monoclonal antibodies against the matrix (M) protein of human metapneumovirus (hMPV) for detection of hMPV from nasopharyngeal swab samples based on the results of real-time RT-PCR. METHODS: Nasopharyngeal swab samples taken from 189 patients aged 0 - 5 years who were suspected of having respiratory tract infections associated with hMPV were used in this study. The samples were tested both by the IC assay and by real-time RT-PCR for detection of hMPV. RESULTS: The sensitivity and specificity of the IC assay for detection of hMPV were 88.8% (95/107) and 92.7% (76/82), respectively. CONCLUSIONS: The IC assay using monoclonal antibodies against the M protein of hMPV is an accurate and fast assay that is suitable as a diagnostic tool for hMPV infection. The optimal timing of the IC assay is 12 hours or more after the onset of fever due to hMPV infection.

Efficacy and safety of colistin for the treatment of infections caused by multidrug-resistant gram-negative bacilli.

BACKGROUND: The efficacy and safety of colistin for the treatment of infections caused by multidrug-resistant gram-negative bacilli have been poorly investigated in Japanese patients. This study was performed to investigate the efficacy and safety of colistin in Japanese patients by analyzing a considerable number of cases. Furthermore, we evaluated the relationship between the plasma concentration and efficacy and safety of colistin in some cases. METHODS: A retrospective cohort study was conducted at Hokkaido University Hospital, analyzing patients treated with colistin (colistimethate sodium) during the period from January 2007 to December 2019. RESULTS: Overall, 42 cases were enrolled. Favorable clinical response was observed in 25 cases (59.5%), with an all-cause 30-day mortality of 33.3% (14/42 cases). Microbiological eradication was achieved in 18 cases (42.9%). Nephrotoxicity was observed in 20 cases (47.6%) and was mild and reversible in all cases. Plasma trough concentrations of colistin determined in nine patients correlated with changes in serum creatinine concentration (⊿) and creatinine clearance (%). The cutoff value of colistin trough concentration for nephrotoxicity was 2.02 µg/mL. CONCLUSION: Our results showed approximately 60% clinical efficacy of colistin therapy against infections caused by multidrug-resistant gram-negative bacilli in the patients. Further studies with larger populations are needed to elucidate the efficacy and safety of colistin in Japanese patients.

Proposal of COVID-19 Clinical Risk Score for the management of suspected COVID-19 cases: a case control study.

BACKGROUND: No clinical scoring system has yet been established to estimate the likelihood of coronavirus disease (COVID-19) and determine the suitability of diagnostic testing in suspected COVID-19 patients. METHODS: This was a single-center, retrospective, observational study of patients with suspected COVID-19 and confirmed COVID-19. Patient background, clinical course, laboratory and computed tomography (CT) findings, and the presence of alternative diagnoses were evaluated. Clinical risk scores were developed based on clinical differences between patients with and without COVID-19. RESULTS: Among 110 patients suspected of having COVID-19, 60.9% underwent polymerase chain reaction (PCR) testing based on the judgment of physicians. Two patients were found to have COVID-19. The clinical characteristics of 108 non-COVID-19 patients were compared with those of 23 confirmed COVID-19 patients. Patients with COVID-19 were more likely to have a history of high-risk exposures and an abnormal sense of taste and smell. The COVID-19 group had significantly higher rates of subnormal white blood cell counts, lower eosinophil counts, and lower procalcitonin levels than the non-COVID-19 group. When blood test results, CT findings, and the presence of alternative diagnoses were scored on an 11-point scale (i.e., "COVID-19 Clinical Risk Score"), the COVID-19 group scored significantly higher than the non-COVID-19 group, more than four points in the COVID-19 group. All non-COVID patients who did not undergo PCR had a score of 4 or less. CONCLUSIONS: The COVID-19 Clinical Risk Score may enable the risk classification of patients suspected of having COVID-19 and can help in decision-making in clinical practice, including appropriateness of diagnostic testing. Further studies and prospective validation with an increased sample size are required.

Evaluation of Daptomycin-Induced Cellular Membrane Injury in Skeletal Muscle.

Daptomycin, a cyclic lipopeptide antibiotic, has bactericidal activity against Gram-positive organisms and is especially effective against methicillin-resistant Staphylococcus aureus. Although daptomycin causes unique adverse drug reactions such as elevation of creatine phosphokinase or rhabdomyolysis, the detailed mechanisms underlying these adverse drug reactions in skeletal muscle are unclear. This study aimed to elucidate whether daptomycin causes direct skeletal muscle cell toxicity and investigate the relationship between daptomycin exposure and musculoskeletal toxicity. First, we evaluated the relationship between daptomycin exposure and skeletal muscle toxicity. Of the 38 patients who received daptomycin intravenously, an elevation in creatine phosphokinase levels was observed in five. The median plasma trough concentration of daptomycin in patients with elevated creatine phosphokinase levels was significantly higher than that in patients whose creatine phosphokinase levels were within the normal range, suggesting that increased exposure to daptomycin is related to elevation in creatine phosphokinase levels. In an in vitro study using human rhabdomyosarcoma cells, daptomycin reduced cell viability and increased membrane damage. These effects were more marked under hypoxic conditions. A necroptotic pathway seemed to be involved because phosphorylated mixed lineage kinase domain-like protein expression was enhanced following daptomycin exposure, which was significantly enhanced under hypoxic conditions. These findings indicate that daptomycin elicits cytotoxic effects against skeletal muscle cells via the necroptotic pathway, and the extent of toxicity is enhanced under hypoxic conditions.

An adult case of severe life-threatening Mycoplasma pneumoniae pneumonia due to a macrolide-resistant strain, Japan: a case report.

BACKGROUND: Until now, the prevalence of macrolide-resistant Mycoplasma pneumoniae (MP) infection among adult patients has been low, and severe MP pneumonia due to a macrolide-resistant strain has seldom been reported. Here, we describe a rare case of severe life-threatening MP pneumonia due to a macrolide-resistant strain in an adult, which was finally treated with fluoroquinolone and tetracycline after failed treatment with macrolide and corticosteroid. CASE PRESENTATION: A 39-year-old apparently healthy woman complained of fever and productive cough. Three days after onset, she was admitted to a local general hospital. On admission, her vital signs were stable except for high-grade fever. The patient's chest X-ray and chest computed tomography images revealed subsegmental consolidation in her right lower lobe. Treatment with ampicillin/sulbactam, and azithromycin were initiated under a clinical diagnosis of community-acquired pneumonia. After treatment initiation, her fever had not subsided, and the pulmonary lesion had extended to the entire lower lobe. Thus, treatment with prednisolone as steroid pulse therapy was initiated from clinical day 7. However, neither her symptoms nor her pulmonary lesion improved; therefore, she was transferred to our hospital for further examination and treatment. On admission (clinical day 14), her indirect hemagglutination titer for MP was elevated at 1:2560, and bronchoalveolar fluid examination yielded positive results for the mycoplasma antigen. Based on these clinical findings, we confirmed a case of severe life-threatening MP pneumonia. Since her respiratory condition was extremely severe, we initiated levofloxacin and tetracycline. Two days later (clinical day 16), her fever, malaise, and hypoxia resolved, and her pulmonary lesions had significantly improved. Further molecular identification yielded the DNA of MP from her bronchoalveolar fluid, and mutation of A2063G in the 23S rRNA gene was revealed. Based on these results and the clinical course, we confirmed our case as severe MP pneumonia due to a macrolide-resistant strain. CONCLUSION: More awareness is needed on the emergence of macrolide-resistant MP infection in adults, because severe infection could develop despite initial treatment with macrolide and steroid therapy, which are generally considered as standard therapy for MP.

Construction of a flow chart-like risk prediction model of ganciclovir-induced neutropaenia including severity grade: A data mining approach using decision tree.

WHAT IS KNOWN AND OBJECTIVE: Haematological toxicities such as neutropaenia are a common side effect of ganciclovir (GCV); however, risk factors for GCV-induced neutropaenia have not been well established. Decision tree (DT) analysis is a typical technique of data mining consisting of a flow chart-like framework that shows various outcomes from a series of decisions. By following the flow chart, users can estimate combinations of risk factors that may increase the probability of certain events. In our previous study, we demonstrated the usefulness of this approach in the evaluation of adverse drug reactions. Therefore, we aimed to construct a risk prediction model of GCV-induced neutropaenia including severity grade. METHODS: We performed a retrospective study at the Hokkaido University Hospital and enrolled patients who received GCV between April 2008 and March 2018. Neutropaenia was defined as an absolute neutrophil count (ANC) <1500 cells/mm3 and a decrease to <75% relative to baseline. We classified the patients who developed neutropaenia in three groups (Grades 2-4) based on the National Cancer Institute-Common Terminology Criteria for Adverse Events. Data collection was achieved through the retrieval of medical records. We employed a chi-squared automatic interaction detection algorithm to construct the DT model and compared the accuracies to the logistic regression model (a conventional statistical method) to evaluate the established model. RESULTS AND DISCUSSION: In total, 396 adult patients were included in the study; 61 (15.4%) developed neutropaenia. Three predictive factors (hematopoietic stem cell transplantation, baseline ANC <3854 cells/mm3 and duration of therapy ≥15 days) were extracted using the DT analysis to produce five subgroups, the incidence of neutropaenia ranged between 1.7% and 52.8%. In each subgroup, patients who developed neutropaenia were categorized based on the severity. The accuracies of each model were the same (84.6%), which indicated precision. WHAT IS NEW AND CONCLUSION: We successfully built a risk prediction model of GCV-induced neutropaenia including severity grade. This model is expected to assist decision-making in the clinical setting.

Evaluation of a Novel Immunochromatographic Assay for Detection of Human Adenoviruses from Throat Swab Samples Compared with Real-time PCR.

BACKGROUND: The aim of this study was to determine the sensitivity and specificity of a novel immunochromatographic assay (ICA) kit, ALSONIC® Adeno (Alfresa Pharma Co., Osaka, Japan), for the detection of human adenovirus (HAdV) from throat swab samples based on the results of real-time PCR. The incubation time required for the novel assay kit (5 minutes) is shorter than that required for other ICA kits that are available in Japan. METHODS: Throat swab samples were taken from 151 patients aged 6 months to 15 years who were suspected of having respiratory tract infections caused by HAdV. RESULTS: The sensitivity and specificity of the ICA for detection of HAdV were 92.2% (83/90) and 95.1% (58/61), respectively, and the assay showed positive and negative predictive values of 96.5% (83/86) and 89.2% (58/65), respectively. CONCLUSIONS: ALSONIC® Adeno is suitable as a diagnostic tool in the acute phase of HAdV infection.

Clinical effectiveness of four neuraminidase inhibitors (oseltamivir, zanamivir, laninamivir, and peramivir) for children with influenza A and B in the 2014-2015 to 2016-2017 influenza seasons in Japan.

The clinical effectiveness of four neuraminidase inhibitors (NAIs) (oseltamivir, zanamivir, laninamivir, and peramivir) for children aged 0 months to 18 years with influenza A and B were investigated in the 2014-2015 to 2016-2017 influenza seasons in Japan. A total of 1207 patients (747 with influenza A and 460 with influenza B) were enrolled. The Cox proportional-hazards model using all of the patients showed that the duration of fever after administration of the first dose of the NAI was shorter in older patients (hazard ratio = 1.06 per 1 year of age, p < 0.001) and that the duration of fever after administration of the first dose of the NAI was shorter in patients with influenza A infection than in patients with influenza B infection (hazard ratio = 2.21, p < 0.001). A logistic regression model showed that the number of biphasic fever episodes was 2.99-times greater for influenza B-infected patients than for influenza A-infected patients (p < 0.001). The number of biphasic fever episodes in influenza A- or B-infected patients aged 0-4 years was 2.89-times greater than that in patients aged 10-18 years (p = 0.010), and the number of episodes in influenza A- or B-infected patients aged 5-9 years was 2.13-times greater than that in patients aged 10-18 years (p = 0.012).

Long-term prognosis of hematogenous vertebral osteomyelitis: Mortality, quality of life, and pain.

BACKGROUND: Hematogenous vertebral osteomyelitis (HVO) has a generally favorable prognosis if appropriate treatment is initiated in its early phase; however, some intractable cases with HVO can develop neurological impairment as well as spinal deformity during the course of treatment and these sequelae may lead to impaired quality of life (QOL). In this study, we aimed to evaluate the long-term relapse rate, mortality, and QOL of patients with HVO. METHODS: In this retrospective case series study, medical records of 60 patients with HVO with a mean follow-up period of 8 years (5-23 years) were reviewed to assess demographic data, details of infection, and clinical course. Mortality rate was assessed using a Kaplan-Meier plot. QOL was measured using the EuroQol 5 Dimension (EQ-5D) questionnaire and residual pain using a numeric rating scale (NRS). RESULTS: HVO relapsed in 4 of 60 patients (7%). Overall 5-year survival rate in 60 patients with HVO was 85%. The factors associated with increased mortality were malignant tumor, diabetes mellitus, chronic use of glucocorticoids, and drug-resistant strains of staphylococcus. Female-to-male ratio, NRS, prevalence of neurological impairment were significantly higher in patients with low EQ-5D score (poor health) compared to those with high EQ-5D score (good health). CONCLUSIONS: Patients with HVO have shorter life expectancy if they have malignancy, diabetes mellitus, chronic use of glucocorticoids, and a history of drug-resistant strains of staphylococcus infection. Female gender, residual neurological defects and persistent back pain are associated with impaired QOL in patients with HVO.

Successful Colistin Treatment of Multidrug-Resistant Pseudomonas aeruginosa Infection Using a Rapid Method for Determination of Colistin in Plasma: Usefulness of Therapeutic Drug Monitoring.

A 56-year-old woman with systemic lupus erythematosus had bacteremia due to multidrug-resistant Pseudomonas aeruginosa (MDRP). She was initially treated with imipenem-cilastatin, tobramycin, and aztreonam; however, MDRP was still detected intermittently in her plasma. Multidrug-susceptibility tests demonstrated that MDRP was susceptible only to colistin. Therefore, in addition to these antibiotics, the administration of intravenous colistin methanesulfonate, a prodrug formula of colistin, was started at a daily dose of 2.5 mg/kg (as colistin base activity). The initial dose setting was based on the patient's renal function (baseline creatinine clearance=32.7 mL/min). After initiating colistin, the patient's C-reactive protein levels gradually decreased. Blood cultures showed no evidence of MDRP on days 8, 14, and 22 after colistin initiation. However, the patient's renal function went from bad to worse owing to septic shock induced by methicillin-resistant Staphylococcus aureus (MRSA) infection. A few days later, the trough plasma levels of colistin were 7.88 mg/L, which appeared to be higher than expected. After decreasing the colistin dose, the patient's renal function gradually improved. On the final day of colistin treatment, the plasma levels decreased to 0.60 mg/L. MDRP could not be detected in blood culture after colistin treatment. Therefore, we successfully treated a case of bloodstream infection due to MDRP by therapeutic drug monitoring (TDM) of colistin. It is suggested that the monitoring of blood colistin levels by liquid chromatography-tandem mass spectrometry can contribute to safer, more effective antimicrobial therapy of MDRP because TDM facilitates quick decisions on dose adjustments.

Sensitivity and Specificity of a Loop-Mediated Isothermal Amplification Assay for the Detection of Mycoplasma Pneumonia from Nasopharyngeal Swab Samples Compared with those of Real-time PCR.

BACKGROUND: The aim of this study was to determine the sensitivity and specificity of a loop-mediated isothermal amplification (LAMP) assay kit for the detection of Mycoplasma pneumonia (Eiken Chemical Co., Ltd, Tokyo, Japan) from nasopharyngeal swab samples compared with those of real-time PCR. METHODS: Nasopharyngeal swab samples taken from 223 patients aged 3 - 18 years who were suspected of having respiratory tract infections associated with Mycoplasma pneumonia were used in this study. The samples were tested both by the LAMP assay and by real-time PCR for detection of Mycoplasma pneumonia. RESULTS: The sensitivity and specificity of the LAMP assay for the detection of Mycoplasma pneumonia were 99.1% (105/106) and 100.0% (117/117), respectively. CONCLUSIONS: The LAMP assay for the detection of Mycoplasma pneumonia is an accurate and fast assay that is suitable as a diagnostic tool in the acute phase of Mycoplasma pneumonia infection.

Association of wastewater SARS-CoV-2 load with confirmed COVID-19 cases at a university hospital in Sapporo, Japan during the period from February 2021 to February 2023.

Wastewater surveillance for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been used to monitor trends in SARS-CoV-2 prevalence in a community without being influenced by clinical testing resources or healthcare-seeking behaviors. Since the rate of mortality from COVID-19 is higher in elderly patients with comorbidities, it is important to protect hospitalized patients from nosocomial infections caused by SARS-CoV-2. SARS-CoV-2 dissemination within a hospital ward was mostly mediated by healthcare workers (HCWs) and patients. HCWs need to understand the occurrence of COVID-19 and reflect this in their infection control measures. The aim of the present study was to determine the potential of SARS-CoV-2 RNA in wastewater as a leading indicator of confirmed COVID-19 cases at a university hospital. The trend of the geometric mean RNA concentrations in wastewater collected in Sapporo corresponded well with that of the number of newly confirmed COVID-19 cases at Hokkaido University Hospital between February 15, 2021 and February 26, 2023 (Pearson's r = 0.8823, p < 0.0001). Our results showed that monitoring SARS-CoV-2 RNA in municipal wastewater was useful for estimating the number of COVID-19 patients in healthcare facilities in the city.

Correlation between antibiotic use and resistance of gram-negative bacteria at a university hospital in Japan from 2013 to 2021: a study using the Japan Surveillance for Infection Prevention and Healthcare Epidemiology (J-SIPHE) system.

OBJECTIVES: The Japan Surveillance for Infection Prevention and Healthcare Epidemiology (J-SIPHE) system aggregates information related to antimicrobial resistance (AMR) measures. We aimed to investigate the correlation between antibiotic use and AMR at a university hospital from 2013 to 2021 in a time series analysis using the J-SIPHE system. We also studied this correlation in each ward (inter-ward analysis). METHODS: Data on antibiotic use and resistance rates were collected from the J-SIPHE system, except for the resistance rate in each ward, which was calculated from the source data prepared for this system. RESULTS: Piperacillin/tazobactam use was positively correlated with piperacillin/tazobactam resistance in Escherichia coli and Klebsiella pneumoniae in the inter-ward analysis, and in Pseudomonas aeruginosa in both analyses. Carbapenem use was positively correlated with meropenem resistance in Enterobacter cloacae in the time series analysis and in P. aeruginosa in both analyses, and imipenem/cilastatin resistance in P. aeruginosa in inter-ward analysis. Quinolone use was positively correlated with levofloxacin resistance in E. coli in both analyses, and in K. pneumoniae in inter-ward analysis. CONCLUSIONS: This is the first study to investigate the correlation between antibiotic use and AMR at a single hospital in time series and inter-ward analyses using the J-SIPHE system and data prepared for this system, suggesting that this system may be useful for promoting AMR measures.

Genotyping of Mycoplasma pneumoniae strains isolated in Japan during 2019 and 2020: spread of p1 gene type 2c and 2j variant strains.

We characterized 118 Mycoplasma pneumoniae strains isolated from three areas of Japan (Saitama, Kanagawa, and Osaka) during the period of 2019 and 2020. Genotyping of the p1 gene in these strains revealed that 29 of them were type 1 lineage (29/118, 24.6%), while 89 were type 2 lineage (89/118, 75.4%), thereby indicating that type 2 lineage was dominant in this period. The most prevalent variant of type 2 lineage was type 2c (57/89, 64%), while the second-most was type 2j, a novel variant identified in this study (30/89, 33.7%). Type 2j p1 is similar to type 2 g p1, but cannot be distinguished from reference type 2 (classical type 2) using the standard polymerase chain reaction-restriction fragment length polymorphism analysis (PCR-RFLP) with HaeIII digestion. Thus, we used MboI digestion in the PCR-RFLP analysis and re-examined the data from previous genotyping studies as well. This revealed that most strains reported as classical type 2 after 2010 in our studies were actually type 2j. The revised genotyping data showed that the type 2c and 2j strains have been spreading in recent years and were the most prevalent variants in Japan during the time-period of 2019 and 2020. We also analyzed the macrolide-resistance (MR) mutations in the 118 strains. MR mutations in the 23S rRNA gene were detected in 29 of these strains (29/118, 24.6%). The MR rate of type 1 lineage (14/29, 48.3%) was still higher than that of type 2 lineage (15/89, 16.9%); however, the MR rate of type 1 lineage was lower than that found in previous reports published in the 2010s, while that of type 2 lineage strains was slightly higher. Thus, there is a need for continuous surveillance of the p1 genotype and MR rate of M. pneumoniae clinical strains, to better understand the epidemiology and variant evolution of this pathogen, although M. pneumoniae pneumonia cases have decreased significantly since the COVID-19 pandemic.

Breaking away from an endemic state of multidrug-resistant Pseudomonas aeruginosa by daily sink disinfection.

The detection rate of multidrug-resistant Pseudomonas aeruginosa in patients admitted to 2 wards and the intensive care unit decreased from 20.3% (129 of 636 isolates) to 4.2% (37 of 889 isolates) after the start of disinfection of hand washing sinks using alkyl diaminoethylglycine hydrochloride.