Japanese journal of infectious diseases最新文献

Helicobacter pylori, Epstein-Barr virus and human papillomavirus are three pathogens associated with various human cancers. This study aimed to investigate the role of these pathogens in gastric cancer in Moroccan population. For this, a retrospective study has been conducted on participants attending the gastroenterology department of Hassan II University Hospital of Fez. A total of 279 participants were enrolled. H. pylori, EBV and HPV were detected and genotyped by PCR. In results, a significant association has been established between H. pylori, EBV and gastric cancer. 93.4% and 43.3% of gastric cancer cases are related to H. pylori and EBV respectively (p≤0.01). H. pylori-EBV co-infection is responsible of 31.6% of gastric cancer cases (p<0.01). Correlation between pathogens genotypes and gastric cancer shows 54.6% of GC EBV positives are carrying the 30 bp deletion in LMP1gene, while 16% of gastric cancers cases are carrying high-risk genotypes of HPV (p=0.21). The obtained results highlight the possible role of co-infection in gastric cancer development.

Dengue viruses enter dermal macrophages which are derived from other tissues after mosquito bites. We examined chemotactic factors derived from the dengue vector mosquito, Aedes albopictus, toward a RAW264 murine macrophage cell line. We found that Elizabethkingia anophelis that was isolated from mosquitoes exhibited migration-inducing activity toward RAW264 cells. The active substances were extracted using ethyl acetate to induce chemotactic movements. Chemotactic activity was eluted in the several fractions using the reversed-phase chromatography, suggesting that multiple substances were responsible for the activity. We isolated three bacterial colonies from the wild A. albopictus mosquitoes collected in Toyama Park, Tokyo prefecture, Japan. The bacterial 16S rRNA gene sequences were the most similar to those of Lonsdalea quercina. These bacteria also exhibited migration-inducing activity toward RAW264 cells. The migration-inducing activity of mosquito bacteria might be a new aspect of mosquito-mediated viral infections.

Japanese spotted fever (JSF) is a tick-borne rickettsial disease prevalent in western Japan, with an increasing incidence and geographical distribution. This retrospective study aimed to describe the clinical features of JSF and identify factors associated with its severe form. We included adult patients with laboratory confirmed JSF in Nagasaki prefecture from 2010 to 2021. Severe JSF was defined by the presence of altered mental status, low blood pressure, or low oxygen saturation. In total, 65 JSF cases were diagnosed. Common symptoms were fever (87%), rash (48%), and fatigue (48%) with eschars detected in 50 (79.4%) of patients. Thirty-eight (60.3%) patients were initially diagnosed with non-JSF conditions. Twenty-one (33.3%) cases were categorized as severe JSF, including one death. Pre-hospital factors associated with severe JSF included age ≥75 (adjusted odds ratio [aOR] 37.53, 95% confidence interval [CI] 3.03-465.38), male sex (aOR 26.5, 95% CI 4.23-166.00), and a treatment delay ≥4 days from onset (aOR 5.96, 95% CI 1.13-31.60). This study highlights diagnostic challenges of JSF due to its non-organ-specific clinical presentation. Delayed initial treatment, advanced age, and male sex significantly increase the risk of severity. It is crucial to further raise awareness of JSF among clinicians and residents in endemic areas.

We report the case of a 77-year-old Japanese woman with neuromyelitis optica spectrum disorder, treated with 15 mg of prednisolone daily, who presented with acute septic shock and altered consciousness due to Dolosigranulum pigrum bacteremia. Intravenous extracellular fluids and broad-spectrum antibiotics were administered as an initial treatment. However, the patient died shortly after admission. We performed 16S rRNA sequencing and analyzed the murJ gene. A phylogenetic tree constructed using the neighbor-joining method showed that the strain belonged to clade C3, according to the classification proposed by Flores Ramos et al. Although D. pigrum, a commensal bacterium of the upper respiratory tract, is rarely associated with infections, it occasionally causes serious infections. Accumulation of clinical and bacteriological data is crucial for understanding the pathogenicity and infections associated with this organism.

Clostridium perfringens, which produces C. perfringens enterotoxin (CPE), is a major causative agent of food poisoning owing to its gastrointestinal symptoms. Genotyping is important for identifying the etiological agent in outbreaks of C. perfringens. We attempted to genotype strains isolated from an outbreak of food poisoning in Toyama in 2023 using single nucleotide polymorphism (SNP) analysis. The strains of C. perfringens were isolated from a piece of curry food consumed by all patients and from the feces of the patients and employees. The cpe gene was detected in isolates from patients and curry food. The cpe-negative isolates were found in patients who consumed curry foods and in employees. The results of the SNP analysis suggest that the patient- and curry-derived isolates were likely from the same source but were unlikely to be related to the employee-derived isolates. The results of the SNP and pulsed-field gel electrophoresis (PFGE) analyses were consistent, indicating that the patient- and curry-derived isolates came from the same source. SNP analysis, a whole-genome-based genotyping method, is a promising alternative to the traditional PFGE method. Further studies are needed to accumulate more experience with genotyping using SNP analysis for the epidemiological investigation of outbreaks of C. perfringens.

We estimated the seroprevalence of anti-SARS-COV-2 IgG in different island groups in Okinawa. A cross-sectional sero-survey was repeated in three periods between July 2020 and February 2021. A total of 2683 serum samples were collected from six referral medical centers, each covering a separate region in Okinawa. In the main island, the seroprevalence was 0.0% (0/392, 95% CI: 0.0-0.9), 0.6% (8/1448, 0.2-1.1), and 1.4% (8/582, 0.6-2.7) at the 1^st, 2^nd, and 3^rd sero-survey, respectively. In the remote islands, the seroprevalence was 0.0% (0/144, 95% CI: 0.0-2.5) and 1.6% (2/123, 0.2-5.8) at the 2^nd and 3^rd survey, respectively. The case detection ratio was 2.7 (95% CI: 1.3-5.3) in the main island and 2.8 (0.7-11.1) in the remote islands during the 3^rd survey. The case detection ratio was the highest in people aged 20-29 years (8.3, 95% CI: 3.3-21.4) in the main island and in those aged 50-59 years (14.1, 2.1-92.7) in the remote islands, suggesting under-reporting of clinical cases by the surveillance system in these subgroups. A sero-survey during an emerging infectious disease epidemic can be useful for validating the reliability of the surveillance system by providing the case detection ratio.

We assessed case fatality rates (CFRs) in cases aged ≥70 years in 10 Japanese prefectures (14.8 million residents) diagnosed between January 2022 and March 2023, when the Omicron variant was dominant in Japan. We selected incident reports on 283,052 study subjects from participating Public Health Centers adhering to the Infectious Diseases Control Law. Cases were passively followed up until the end of their isolation, date of death or 28 days after the COVID-19 diagnosis, whichever occurred first. We calculated age-standardized CFRs with 95% confidence intervals (CI) using the Japanese population aged 70-79, 80-89 and ≥90 in 2022 divided into 16 subgroups according to the period of COVID-19 diagnosis. The total overall CFR was 1.59% (95% CI 1.55-1.64); it ranged between 0.67% (95% CI 0.38-0.96, May 23-June 19) and 2.58% (95% CI 2.36-2.80, January 31-February 27). We observed three peaks of age-standardized CFRs paralleling the 6^th, 7^th and 8^th endemic COVID-19 waves driven by Omicron in Japan (2.2% January 31-February 27, 1.0% July 18-August 14 and 1.6% December 26-January 22, 2023, respectively). Population-based CFRs for Omicron variant COVID-19 in Japanese aged ≥70 years remained <3% throughout the period January 2022-March 2023, including during three large endemic waves in this country.

Escherichia albertii is an emerging foodborne pathogen causing diarrhea. Though various animals, especially poultry, serve as reservoirs, the transmission of E. albertii among reservoirs and the risk to humans remain unclear. This study investigated an E. albertii infected infant with poultry exposure and collected samples from contact persons, poultries, and environment to better understand the transmission dynamics of E. albertii. One E. albertii isolate from contact person, seven isolates from poultries, and six isolates from environment were recovered, respectively. Whole genome sequencing analysis showed that eight strains derived from poultry or environment and classified as ST4633, shared great similarity (cgSNP ≤ 20). However, the patient-derived strain ESA311 had a cgSNP difference of 1165 with human strain ESA339, and differed from poultry and environmental strains (cgSNP range 2417 to 14997), suggesting a distant relatedness. Whole genome phylogeny showed several human-derived E. albertii strains were clustered with those from animal origins. Our results suggested that family-breeding poultry constituted a possible reservoir of E. albertii, with the environment acting as a crucial vector for the spread of these bacteria, posing a risk to humans. Further poultry surveillance is needed to elucidate public health risks associated with E. albertii infection.

In Japan, as elsewhere, the COVID-19 pandemic affected the notification trends of respiratory syncytial virus (RSV) infection. Here, we describe the epidemiological trends of RSV cases among children reported during 2018-2021 in Japan, based on the national surveillance system. Compared to 2018 and 2019, 2020 saw an unprecedented decrease in RSV notifications per sentinel site. However, 2021 experienced an unseasonably early and high peak in week 28 (peak week in 2018 and 2019: week 37) with a large resurgence in notifications, nationwide and across regions. Regarding age, compared to 2018 and 2019, the number and proportion of cases aged 2, 3, and ≥4-years increased substantially in 2021 but the number of cases aged <1 year decreased slightly. Furthermore, in 2021, the ratio of notifications per site from outpatient clinics to hospitals increased, suggesting a proportionate increase in clinically milder case diagnoses. Notably, RSV-attributed deaths from vital statistics also dropped substantially in 2020 and rebounded in 2021, but were fewer than in 2018 or 2019. While RSV incidence likely declined in 2020 (possibly from COVID-19 countermeasures) and increased in 2021, notifications in 2021 appeared to be associated with milder presentations. Given unpredictable RSV epidemiology, continuous monitoring and pluralistic assessments are imperative.

This study aims to understand the clinical characteristics of severe fever with thrombocytopenia syndrome (SFTS) and screen risk factors for the prognosis. This retrospective study collected the epidemiological, demographic, and clinical and laboratory data of 101 patients with SFTS. Patients were divided into survival and deceased groups, and then logistic regression model was used to evaluate the association between predictors and prognostic variables. A joint detection factor model was constructed, and a receiver operating characteristic (ROC) curve was drawn. A nomogram was established using the R language, and its efficiency in the diagnosis of SFTS was evaluated using the Calibrate curve. Patients in the deceased group were more likely to show an elder age, a shorter hospitalization stay, renal failure and multiple organ failure compared with that of the survival group. There were statistical differences in the neutrophil percentage, lymphocyte percentage, neutrophil-to-lymphocyte ratio, platelet (PLT), AST, AST/ALT, blood urea nitrogen, lactate dehydrogenase, hydroxybutyrate dehydrogenase, thromboplastin time and activated partial thromboplastin time between the two groups. Lymphocyte percentage, PLT, and AST/ALT were independent risk factors for mortality in SFTS patients. We established a prediction model for SFTS mortality with good efficiency.