Infection In Japan Research Articles

Chronic hepatitis B costs and healthcare resource utilization in a Japanese patient population: a retrospective cross-sectional analysis.

Data on the economic burden of chronic hepatitis B infection in Japan are lacking. This study investigated healthcare resource utilization and costs of chronic hepatitis B infection and liver complications in Japan. This non-interventional study used the Medical Data Vision database. For the first analysis, a population with prevalent chronic hepatitis B infection and absence of liver complications was identified and further stratified by nucleos(t)ide analog treatment history. In the second analysis, patients with prevalent chronic hepatitis B infection and incident liver complications were identified. Patients were followed for 1 year in the first analysis and 2 years in the second analysis. Numbers of all-cause outpatient, inpatient, emergency hospitalizations, medication use, and associated costs per person-year were described across patients without/with nucleos(t)ide analog treatment and in those without/with liver complications. For patients with chronic hepatitis B infection, 75,967 had no liver complications while 17,678 patients had liver complications. All-cause outpatient visits were the largest contributor to healthcare resource utilization and costs, for patients without and with liver complications, and were numerically higher for patients on nucleos(t)ide analog than not. Patients with liver complications had numerically higher all-cause healthcare resource utilization and total costs than patients without complications. Japan has a high economic burden of chronic hepatitis B infection, particularly in patients with liver complications. Optimizing treatment to prevent complications may reduce this burden.

Clinic Characteristics and Antibiotic Prescribing for Acute Respiratory Infections in Japan

This cross-sectional study examined clinic characteristics associated with antibiotic prescribing for acute respiratory infections in primary care in Japan.

Real-world trends in acute viral hepatitis in Japan: A nationwide questionnaire-based survey.

The actual incidence of acute viral hepatitis in Japan remains unclear. We aimed to investigate trends in the incidence of acute hepatitisB and C infections in Japan. A nationwide, multicenter, retrospective questionnaire-based survey was conducted. Participating hospitals received questionnaires through nationwide geographically distributed regional core centers certified as specialists in hepatitis treatment. The questionnaire included hospital size and the number of patients diagnosed with acute hepatitisB or C during each fiscal year (FY) from 2015 to 2022. The sex distribution in each FY was also documented. Comparisons were made before and during the COVID-19 era (2015-2019 vs. 2020-2022), and between populous and non-populous prefectures. Responses to the questionnaires were obtained from 127 institutions in 29 prefectures covering eight regions in Japan. A median of 127.0 patients with acute hepatitisB (interquartile range [IQR] 106.5-131.8 patients) were reported during each FY, and the incidence significantly decreased during the fiscal years 2020-2022 compared with the fiscal years 2015-2020 (median 96.0 [IQR 91.0-103.0] patients vs. 131.0 [IQR 128.0-134.0] patients; p=0.03). A median of 10.0 (IQR, 7.8-13.5) patients were reported with acute hepatitisC during each FY. The proportions of men in acute hepatitis B and C were significantly higher in populous prefectures. Populous prefectures had a higher proportion of men among viral hepatitis patients than non-populous prefectures. Estimating the high-risk populations in each area could provide insights to advance the elimination of viral hepatitis.

Factors associated with mortality in patients with catheter-related bloodstream infection in Japan: A multicenter retrospective study

Factors associated with mortality in patients with catheter-related bloodstream infection in Japan: A multicenter retrospective study

Epidemiology and molecular evolution of GI.1 sapovirus in the recent era.

Sapovirus (SaV) infection is increasing worldwide. Herein, we provided evidence of a significant increase in SaV infection in Japan during 2010-2022, primarily due to the considerable (p = 0.0003) rise of the GI.1 genotype. Furthermore, we found that all major and minor SaV outbreaks in Japan, including the largest SaV outbreak in 2021-2022, were caused by the GI.1 genotype. Therefore, to get insight into the underlying molecular mechanism behind this rising trend of the SaV GI.1 type, we selected 15 SaV GI.1 outbreak strains for complete genome analysis through next-generation sequencing. Phylogenetically, our strains remained clustered in different branches in lineages I and II among the GI.1 genotype. We showed all amino acid (aa) substitutions in different open reading frames (ORFs) in these strains. Importantly, we have demonstrated that the strains involved in the largest SaV outbreak in Japan in 2021-2022 belonged to lineage II and possessed the third ORF. We have identified some unique aa mutations in these major outbreak strains in the NS1 and NS6-NS7 regions that are thought to be associated with viral pathogenicity, cell tropism, and epidemiological competence. Thus, in addition to enriching the database of SaV's complete sequences, this study provides insights into its important mutations.

Diagnosis of COVID-19: Is Fever the Best Indicator of COVID-19 in Vaccinated SARS-CoV-2-Positive Adults?

Coronavirus disease 2019 (COVID-19) vaccination is highly recommended to prevent the onset and severity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in Japan. However, the impact of COVID-19 vaccination on the manifestations or presenting symptoms of SARS-CoV-2 infection in daily clinical practice remains unclear. This retrospective single-center study was conducted from April 2021 to July 2022 in Japan. We compared the clinical manifestations of SARS-CoV-2 infection in636 COVID-19-positive patients who visited our outpatient fever clinic, both COVID-19-vaccinated and unvaccinated. During the study period, the COVID-19 vaccination rate at the time of infection was 77.2% (n=491/636), with a median of two doses. Most manifestations, including fever, were reduced in the vaccinated group (n=196) compared to the non-vaccinated group (n=142). The temperature at the clinic decreased significantly as the number of vaccinations increased. Fever was the most common manifestation in the non-vaccinated group (76%, n=108/142), while only 30% (n=59/196) of those who received three or more COVID-19 vaccinations experienced fever. However, sore throat and cough were observed more frequently in the vaccinated group compared to the non-vaccinated group. Fever may not be a reliable indicator of SARS-CoV-2 infection in vaccinated individuals, as its frequency is significantly reduced by vaccination. However, since sore throat and cough are more frequently observed in vaccinated individuals, these symptoms could be useful for recommending COVID-19 testing even in the absence of fever, aiding in the prevention of infectious outbreaks.

Travel-associated sexually transmitted infections in Japan: An observational study using imported infectious disease registry data.

International travel is a risk factor for acquiring sexually transmitted infections (STIs) owing to factors such as increased sexual opportunities, a sense of freedom, and the allure of the sex industry. We investigated the incidence of travel-associated STIs in Japan using data from the Japan Registry for Infectious Diseases from Abroad (J-RIDA) reported by 17 participating medical institutions between October 2017 and December 2022. Data were collected on the patients' age, sex, nationality, chief complaint, whether they had visited a travel clinic before travel, travel history, and final diagnosis. Of 4545 cases of travel-associated illness reported, 52 (1.1%) were STIs. Most patients with STIs were male (81%) with a median age of 31 years. HIV (17%), genital herpes (13%), syphilis (13%), and gonorrhea (12%) were the most frequently reported STIs. Only one patient had visited a travel clinic before travel. Promoting awareness and vaccination is crucial for preventing travel-associated STIs.

Burden of respiratory syncytial virus infections in older adults with acute respiratory infection in Japan: An epidemiological study among outpatients

BackgroundRespiratory syncytial virus (RSV) is a leading cause of acute respiratory illness, with severe outcomes in older adults. Information on the prevalence, hospitalization rate, and impact on the health-related quality of life (HRQoL) of RSV in older adults with acute respiratory infections (ARI) in outpatient settings in Japan is limited. MethodsThis multi-center epidemiological study included outpatients aged ≥60 years presenting with ARI between August 2021 and February 2023. Nasal and throat swabs were collected and tested by reverse transcription polymerase chain reaction (RT-PCR). The prevalence of RT-PCR-confirmed RSV (cRSV)-ARI, cRSV-lower respiratory tract disease (LRTD), and other respiratory viruses was calculated by season, region, age group, and RSV subtype. HRQoL was assessed via patient-reported outcomes. ResultsThe study included 923 ARI episodes (cRSV-ARI: N = 24; non-cRSV-ARI: N = 899). In years 1 and 2 (August 2021–July 2022 and August 2022–February 2023), the prevalence of cRSV-ARI was 2.5% and 2.8%, respectively. There was a predominance of RSV-B and RSV-A subtypes in years 1 and 2, respectively. In years 1 and 2 combined, 37.5% of cRSV-ARI cases had lower respiratory tract infection; all cRSV-LRTD cases occurred in those aged 60–74 years. RSV-ARI cases reported throat, chest, and respiratory symptoms, leading to impaired functioning and HRQoL. ConclusionsDuring the observed study period, RSV was circulating among older adults in Japan. RSV was a leading cause of ARI and LRTD. More data are needed to fully clarify the burden of RSV among older adults in Japan.

Fatal SARS-CoV-2 Infection among Children, Japan, January-September 20221.

To determine the characteristics of pediatric patients 0-19 years of age who died after onset of SARS-CoV-2 infection in Japan during January 1-September 30, 2022, we reviewed multiple sources. We identified 62 cases, collected detailed information from medical records and death certificates, and conducted interviews, resulting in 53 patients with detailed information for our study. Among 46 patients with internal causes of death (i.e., not external causes such as trauma), 15% were <1 year of age, 59% had no underlying disease, and 88% eligible for vaccination were unvaccinated. Nonrespiratory symptoms were more common than respiratory symptoms. Out-of-hospital cardiac arrest affected 46% of patients, and time from symptom onset to death was <7 days for 77%. Main suspected causes of death were central nervous system abnormalities (35%) and cardiac abnormalities (20%). We recommend careful follow-up of pediatric patients after SARS-CoV-2 infection during the first week after symptom onset, regardless of underlying diseases.

Comorbidities and Contraindicated Medications in Patients with Chronic Hepatitis C Infection in Japan: a Real-World Database Study

Comorbidities and Contraindicated Medications in Patients with Chronic Hepatitis C Infection in Japan: a Real-World Database Study

Clinical Practice Guidelines for the Management of Congenital Cytomegalovirus Infection in Japan 2023: Executive Summary.

Congenital cytomegalovirus (cCMV) infection is the most common congenital infection in developed countries. Although a standard therapy has not yet been established, evidence for the management of cCMV infection has been accumulating. The first edition of the "Clinical Practice Guidelines for the Management of Congenital Cytomegalovirus Infection" was published in Japan in 2023. This summary outlines the clinical questions (CQs) in the guidelines, with reference to the Japanese Medical Information Distribution Service Manual. Overall, 20 CQs with statements regarding prenatal risk assessment, prevention and management at diagnosis (CQs 1-1-1-3), diagnosis (CQs 2-1-2-6), treatment (CQs 3-1-3-7) and follow-up requirements (CQs 4-1-4-4) have been discussed. For each statement, the levels of recommendation, evidence and consensus rates were determined. These guidelines will assist in the management of patients with cCMV infection.

Clinical Characteristics of Pediatric Parainfluenza Virus Infections: A Comparative Analysis of Parainfluenza Virus Serotypes 1-4 From April 2021 to October 2023 in Hokkaido, Japan.

Parainfluenza virus (PIV) is widely known as a causative virus of acute respiratory tract infections in children, and 4 serotypes (PIV-1-PIV-4) have been identified. The purpose of the present study was to clarify the clinical characteristics of the PIV serotypes in pediatric PIV infections in Japan. Between April 2021 and October 2023, 8821 children aged <16 years who presented with respiratory symptoms underwent multiplex polymerase chain reaction analyses at the Department of Pediatrics, NTT Medical Center Sapporo. All 1490 cases in which PIV was detected were analyzed for their clinical characteristics by PIV serotypes. Of the 1490 cases, 608 were positive for a single PIV serotype: 91 (13.5%) for PIV-1, 54 (4.8%) for PIV-2, 361 (62.1%) for PIV-3 and 102 (19.6%) for PIV-4. The median ages were 3.5 years for PIV-1, 5.4 years for PIV-2, 1.9 years for PIV-3 and 2.2 years for PIV-4, with a significantly older age for PIV-2. Compared with the other serotypes, croup was significantly more common in PIV-1 and lower respiratory tract infection was significantly more common in PIV-4. Of the 608 cases with a single PIV serotype, 114 were hospitalized. The proportion of hospitalized patients was higher for PIV-4 than for the other PIV serotypes, but the difference was not significant. Lower respiratory tract infection was more frequent in PIV-4 than in the other PIV serotypes, and PIV-4 infection may increase the risk of hospitalization.

Disseminated septic arthritis caused by Ureaplasma urealyticum in an immunocompromised patient with hypogammaglobulinemia after rituximab therapy

Abstract Purpose Ureaplasma urealyticum is a rare pathogen associated with septic arthritis that predominantly affects patients with hypogammaglobulinemia. Bacterial identification of fastidious organisms is challenging because they are undetectable by routine culture testing. To the best of our knowledge, this is the first report of septic arthritis induced by U. urealyticum infection in Japan. Case description We describe the case of a 23-year-old Japanese female with secondary hypogammaglobulinemia (serum immunoglobulin level &lt; 500 mg/dL), identified 8 years after treatment with rituximab. The patient presented with persistent fever and polyarthritis that were unresponsive to ceftriaxone and prednisolone. Contrast-enhanced computed tomography and gallium-67 scintigraphy revealed effusion and inflammation in the left sternoclavicular, hip, wrist, knee, and ankle joints. Although Gram staining and bacterial culture of the drainage fluid from the left hip joint were negative, the condition exhibited characteristics of purulent bacterial infection. The patient underwent empirical treatment with doxycycline, and her symptoms promptly resolved. Subsequent 16S ribosomal RNA (rRNA) gene sequencing of the joint fluid confirmed the presence of U. urealyticum, leading to the diagnosis of septic arthritis. Combination therapy with doxycycline and azithromycin yielded a favorable recovery from the inflammatory status and severe arthritic pain. Conclusion This case highlights U. urealyticum as a potential causative agent of disseminated septic arthritis, particularly in patients with hypogammaglobulinaemia. The 16S rRNA gene analysis proved beneficial for identifying pathogens in culture-negative specimens, such as synovial fluid, in suspected bacterial infections.

Cost-Effectiveness Analysis of Maternal Respiratory Syncytial Virus Vaccine in Protecting Infants from RSV Infection in Japan.

Respiratory syncytial virus (RSV) is one of the major causes of respiratory tract infections among children. Until recently, the monoclonal antibody palivizumab was the only RSV prophylaxis available in Japan. In 2024, the bivalent RSV prefusion F protein-based (RSVpreF) vaccine was approved for the prevention of RSV infection in infants by active immunization of pregnant women. In this study, we assessed the cost-effectiveness of a combined strategy of RSVpreF vaccine and palivizumab in Japanese setting. Using a Markov model, we evaluated prevented cases and deaths of medically attended RSV infections from birth to age 11months for each of the three healthcare settings: inpatient (hospitalization), emergency department visits, and outpatient visits. Incremental cost-effectiveness ratios (ICERs) were calculated from economic outcomes (intervention costs, medication costs, and productivity losses) and quality-adjusted life years (QALYs). Further, we calculated the maximum price of RSVpreF vaccine within which the program would be cost-effective. In comparison with the current prophylaxis (palivizumab alone), a combined prophylaxis of year-round RSVpreF vaccination of pregnant women and palivizumab prescription for premature infants born in < 32weeks gestational age (wGA) and all infants with high risk prevented 14,382 medically attended cases of RSV (hospitalization, 7490 cases; emergency department, 2239 cases; outpatient, 4653 cases) and 7 deaths, respectively. From a healthcare payer perspective, when the price of RSVpreF vaccine was equal to or less than ¥23,948 (US$182), a combination prophylaxis was cost-effective under the ICER threshold of ¥5million per QALY. The other combination prophylaxis of year-round RSVpreF vaccination and palivizumab prescription of premature born in < 32wGA regardless of risk in infants was a dominant strategy (more effective and less costly). A combined prophylaxis of year-round RSVpreF vaccine and palivizumab could be a cost-effective strategy to protect neonates throughout the infant stage (< 1years old) in Japan.

The emerging outbreak of syphilis infections in Japan: A public health concern

The emerging outbreak of syphilis infections in Japan: A public health concern

Real-world evidence of systemic treatment practices for biliary tract cancer in Japan: Results of a database study.

To describe the real-world treatment patterns of systemic therapies for biliary tract cancer (BTC) and to examine the frequency and management of biliary infection in Japan. Patients diagnosed with BTC and prescribed systemic therapy between January 2011 and September 2020 were retrieved from the Japanese Medical Data Vision database. The look-back period was set to 5 years. Patient characteristics, treatment patterns, and biliary infection-induced treatment interruption were analyzed. The full analysis set comprised 22 742 patients with a mean age of 71.0 years and 61.6% were male. The most common BTC type was extrahepatic cholangiocarcinoma (44.6%). The three most common first-line regimens were S-1 monotherapy (33.0%), gemcitabine+cisplatin (32.5%), and gemcitabine monotherapy (18.7%) over the entire observation period (January 2011-September 2021). Patients who received monotherapies tended to be older. Biliary infection-induced treatment interruption occurred in 29.5% of patients, with a median time to onset of 64.0 (interquartile range 29.0-145.0) days. The median duration of intravenous antibiotics was 12.0 (interquartile range 4.0-92.0) days. These results demonstrated potential challenges of BTC in Japanese clinical practice particularly use of multiple regimens, commonly monotherapies, which are not recommended as first-line treatment, and the management of biliary infections during systemic therapy.

Incidence and mortality of community-acquired and nosocomial infections in Japan: a nationwide medical claims database study

BackgroundIt is important to determine the prevalence and prognosis of community-acquired infection (CAI) and nosocomial infection (NI) to develop treatment strategies and appropriate medical policies in aging society.MethodsPatients hospitalized between January 2010 and December 2019, for whom culture tests were performed and antibiotics were administered, were selected using a national claims-based database. The annual trends in incidence and in-hospital mortality were calculated and evaluated by dividing the patients into four age groups.ResultsOf the 73,962,409 inpatients registered in the database, 9.7% and 4.7% had CAI and NI, respectively. These incidences tended to increase across the years in both the groups. Among the patients hospitalized with infectious diseases, there was a significant increase in patients aged ≥ 85 years (CAI: + 1.04%/year and NI: + 0.94%/year, P < 0.001), while there was a significant decrease in hospitalization of patients aged ≤ 64 years (CAI: -1.63%/year and NI: -0.94%/year, P < 0.001). In-hospital mortality was significantly higher in the NI than in the CAI group (CAI: 8.3%; NI: 14.5%, adjusted mean difference 4.7%). The NI group had higher organ support, medical cost per patient, and longer duration of hospital stay. A decreasing trend in mortality was observed in both the groups (CAI: -0.53%/year and NI: -0.72%/year, P < 0.001).ConclusionThe present analysis of a large Japanese claims database showed that NI is a significant burden on hospitalized patients in aging societies, emphasizing the need to address particularly on NI.

Pharmacoeconomic study of anti-influenza virus drugs in Japan based on a network meta-analysis.

An analysis was conducted in Japan to determine the most cost-effective neuraminidase inhibitor for the treatment of influenza virus infections from the healthcare payer's standpoint. This study reanalysed the findings of a previous study that had some limitations (no probabilistic sensitivity analysis and quality of life scores measured by the EQ-5D-3L instead of the EQ-5D-5L) and used a decision tree model with only three health conditions. This study incorporated new data from a network meta-analysis study into the first examination. The second examination involved constructing a new decision tree model encompassing seven health conditions and identifying costs, which consisted of medical costs and drug prices based on the 2020 version of the Japanese medical fee index. Effectiveness outcomes were measured using EQ-5D-5L questionnaires for adult patients with a history of influenza virus infections within a 14-day time horizon. Deterministic and probabilistic sensitivity analyses were performed to examine the uncertainty. In the first examination, the base-case cost-effectiveness analysis confirmed that oseltamivir outperformed laninamivir, zanamivir and peramivir, making it the most cost-effective neuraminidase inhibitor. The second examination revealed that oseltamivir dominated the other agents. Both deterministic and probabilistic sensitivity analyses showed robust results that validated oseltamivir as the most cost effective among the four neuraminidase inhibitors. This study thus reaffirms oseltamivir's position as the most cost-effective neuraminidase inhibitor for the treatment of influenza virus infections in Japan from the perspective of healthcare payment. These findings can help decision makers and healthcare providers in Japan.

A Report on Changes in the Lifestyle of Buddhist Temple Priests Before and After the Spread of the New Coronavirus Infection in Japan

Japan has been taking measures to prevent new-type coronavirus infection by promoting the spread of vaccination, testing, and therapeutic drugs, and by further strengthening the flow from detection to early treatment, as well as by improving and strengthening the medical care delivery system, including the securing of hospital beds, in anticipation of a worst-case scenario. However, on January 27, 2023, the Infectious Diseases Subcommittee of the Health Sciences Council summarized that new coronavirus infection (COVID-19) should be placed in category 5 infectious diseases because it is not considered a condition that meets the private rights restrictions under the Infectious Diseases Act. On May 8, the status was changed to a category 5 infectious disease1). In accordance with this change, workers were subjected to environmental changes, such as behavioral restrictions, the recommendation to wear masks, and ventilation, which had been introduced in FY 2020 due to the coronary disaster. In addition, as far as the authors researched, they could not find any articles that clarified the actual working conditions of priests working at temples in Japan. Therefore, in this study, the authors clarified the working conditions of monks and the changes in their lifestyle before and after the Corona disaster.

Disease burden of main bacterial infections in Japan, 2015–2020: A population-level study

IntroductionComprehensive evidence about the burden of infectious diseases in the Western Pacific Region is scarce. We thus examined the disease burden of infectious diseases in Japan in terms of disability-adjusted life years (DALYs). MethodsWe extracted national claims data from Japan's universal health insurance system to estimate the burden of disease for selected infections between 2015 and 2020 using DALYs. The mortality rate, disability duration and severity weight of each disease were estimated based on national data and literature reviews. ResultsDisease burden per 100,000 population was 1307.0 in 2015 and 972.1 in 2020 for bloodstream infections (BSI), 796.5 DALYs in 2015 and 498.9 DALYs in 2020 for pneumonia, 171.5 in 2015 and 149.4 in 2020 for meningitis and 11.6 in 2015 and 11.4 in 2020 for urinary tract infections (UTI). Only surgical site infections (SSI) showed a slightly increasing trend over the 5-year period, from 2.2 in 2015 to 2.8 in 2020. ConclusionsOur results showed that the disease burden of the five major infectious diseases was higher in Japan than in other countries. However, while the burden of SSI increased, the burden of pneumonia, meningitis, BSI and UTI gradually decreased year on year. The possible causes of the decreased morbidity should be examined in future work.