Clusters of nosocomial coronavirus disease 2019 (COVID-19) were reported globally during the recent pandemic. Unfortunately, these clusters negatively impacted inpatient morbidity, mortality, and hospital functions. Using epidemiological data and whole genome sequencing (WGS) of SARS-CoV-2, the present study investigated an outbreak of COVID-19 at a university hospital. Eight inpatients and 13 healthcare workers tested positive for SARS-CoV-2 during a one-month period. Whole genome sequencing (WGS) of the virus in 11 patients revealed that two variants of concern belonging to the Omicron sublineages, BA.2.3 and BA1.1.2, had caused the outbreak during a time when the proportion of the Omicron lineage in the community was changing. When variants of concern are undergoing mutation, a response to the outbreak should be made with multiple variants in mind, even in the absence of epidemiological data showing close contact or other potential vectors of infection, and awareness about infection prevention and control should be raised to safeguard patient safety.

Hawaiʻi, the United States’ most western geographic state in the Pacific, is intermediate between the North and South American continents and Indo-Pacific regions, including Japan. The Hawaiian Islands’ tropical environmental conditions provide favorable ecosystems for various infectious pathogens, their vectors, and reservoirs. This creates a conducive environment for-transmission of various zoonotic diseases that affect both humans and animals. Hawaiʻi has experienced an increase in outbreaks of dengue, leptospirosis, and murine typhus. Further, toxoplasmosis and neuroangiostrongyliasis cases remain prevalent throughout the state, and the putative presence of autochthonous Zika cases in a retrospective study may be of national public health concern. Understanding the factors that affect the transmission and distribution of zoonoses is necessary to identify at-risk places and populations. The One Health approach seeks to understand, report, and interpret these factors and requires collaborations between private and government institutions. One Health should focus its efforts on neglected tropical diseases (NTD) and prioritize intervention development to control and prevent the transmission of diseases that spread between animals and humans. This review will focus on the epidemiological and clinical characteristics of under-recognized zoonotic and NTD affecting Hawaiʻi: leptospirosis, murine typhus, neuroangiostrongyliasis, toxoplasmosis, dengue, and Zika infections.

The number of syphilis cases in Tokyo has been found to increase in recent years. We conducted a descriptive epidemiology to elucidate the actual status of syphilis. Data on age, sex, disease stage, and presumed sexual partner of syphilis cases reported in Tokyo were tabulated and analyzed. A total of 9,419 syphilis cases have been reported between 2019 and 2022. There was a particularly sharp rise in the number of reported cases from 2021 to 2022. Comparing 2020 to 2022, the number of syphilis cases among women in their 20s, rapidly increased, more than triple. Furthermore, the number of pregnant women among syphilis cases increased in 2022. Despite the rapid increase in the number of young women with syphilis, there has been no increase in cases of congenital syphilis. One of the reasons may be that syphilis was detected early in pregnancy due to the high antenatal checkup rate in Tokyo. However, the continued incidence of syphilis among young women may increase congenital syphilis in the future. Public health strategy should include educational activities targeting high-risk populations or adolescents, early and appropriate testing, and treatment for preventing progression of syphilis.

Biofilm-producing methicillin-resistant Staphylococcus aureus (MRSA) and coagulase-negative Staphylococci (MR-CoNS) are a clinical challenge for the treatment of healthcare-associated infections. As alternative antimicrobial options are needed, we aimed to determine the effect of curcumin-chitosan magnetic nanoparticles on the biofilm of staphylococcal clinical isolates. MRSA and CoNS clinical isolates were identified by MALDI-TOF mass spectrometry. Antimicrobial susceptibility testing was performed by broth microdilution. Nanoparticles were synthesized by co-precipitation of magnetic nanoparticles (MNP) and encapsulation by ionotropic gelation of curcumin (Cur) and chitosan (Chi). Biofilm inhibition and eradication by nanoparticles with and without the addition of oxacillin was assessed on staphylococcal strains. Cur-Chi-MNP showed antimicrobial activity on planktonic cells of MRSA and MR-CoNS strains and inhibited biofilm of MRSA. The addition of OXA to Cur-Chi-MNP increased biofilm inhibition and eradication activity against all Staphylococci strains (p=0.0007); higher biofilm activity was observed in early biofilm stages. Cur-Chi-MNP showed antimicrobial and biofilm inhibition activity against S. aureus. The addition of OXA increased biofilm inhibition and eradication activity against all Staphylococci strains. A combination treatment of Cur-Chi-MNP and OXA could be potentially used to treat staphylococcal biofilm-associated infections in its early stages before the establishment of biofilm bacterial cells.

Since the COVID-19 pandemic has affected the epidemiological pattern of pharyngoconjunctival fever (PCF) caused by human adenovirus (HAdV), the prevalence and type distribution of HAdVs associated with PCF among children in Osaka, Japan, between 2019 and 2023 have been analyzed. The number of reported PCF cases in Osaka decreased from 2020 to 2022, followed by an unprecedented increase in 2023. HAdV-C strains, including types C1, C2, and C5, were annually detected in pathogen surveillance in Osaka. HAdV-B3 was not detected for 2 years and 9 months from March 2020, and the number of detections increased from July 2023. In total, HAdV-B3 was the most frequently detected (27 of 52 strains), and genetic analysis of its hexon hypervariable regions showed that, except for one strain, the HAdV-B3 strains identified after 2022 had different amino acid substitutions compared to those identified in 2019 and 2020. These results suggest that the PCF epidemic in 2023 was predominantly caused by variant strains of HAdV-B3, and children who have not acquired immunity against HAdV-B3 between 2020 and 2022 were thought to be infected. The impact of COVID-19 on the prevalence of HAdV infections needs to be continuously evaluated through surveillance.

Chronic hepatitis C is a serious condition with relevant public health implications. In Portugal, the prevalence of detectable HCV antibodies is about 0,54%, with higher values in risk groups. Compared to the general population, the prevalence of HCV infection is higher in individuals with psychiatric disorders. There are no studies reporting the prevalence of HCV antibodies in Portuguese psychiatric patients, or in patients with substance use disorders.We carried an observational, prospective study during a period of one year, for patients followed at the Dual Pathology Outpatient and Inpatient Unity of the Coimbra Hospital and University Center, and patients were tested for HCV antibodies. Of 149 patients, 17.4% had positive HCV antibodies and 7.38% had detectable HCV RNA. Patients with confirmed CHC were mostly male inpatients, aged 50 to 59 years, and reported unprotected sex with more than one concurrent partner in the previous six months; their main psychiatric diagnosis was “Disorders due to use of multiple specified psychoactive substances, including medications”.This study reports a very high prevalence of positive HCV antibodies and confirmed CHC in patients followed in the Dual Pathology Outpatient and Inpatient Unity. This prevalence is higher than in general Portuguese population.

We report the isolation of Helicobacter cholecystus from a positive blood culture from a 58-year-old man in China who had bacteremia and acute cholecystitis. The patient’s condition improved after symptomatic support treatment and subtotal cholecystectomy. This finding suggests that H. cholecystus should be considered as potential human pathogens.

The accurate identification of individuals without prior infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is pivotal for seroepidemiological research and vaccine trials. Because of widespread COVID-19 vaccination, the anti-nucleocapsid antibody continues to serve as a valuable marker for individuals without a history of COVID-19. This study aimed to comprehensively assess anti-nucleocapsid antibody positivity using diverse commercial and in-house immunoassays among individuals who contracted COVID-19 more than 3 years ago. We enrolled 44 participants with laboratory-confirmed COVID-19 between January and May 2020 from Seoul National University Hospital and its community treatment centers. The results showed anti-nucleocapsid antibody positivities ranged from 45.5% to 87.9% depending upon the immunoassay used. The study highlights the importance of considering the limited anti-nucleocapsid antibody positivity in participants with a distant COVID-19 history in seroepidemiological or vaccine research.

In Japan, based on the National Epidemiological Surveillance of Infectious Diseases (NESID) Program, influenza cases from ~5,000 sentinel sites are monitored weekly as part of influenza surveillance (as number of influenza cases/sentinel site). One limitation is that the number of influenza tests conducted is not reported. Separately, the National Hospital Organization (NHO), with ~140 hospitals, routinely publishes three indicators: number of influenza tests, influenza-positive case counts, and test positivity. We used NESID and NHO data from April 2011 to June 2022 to assess the usefulness of multiple indicators to monitor influenza activity. Temporal trends of the NHO and NESID indicators were similar, and NHO indicator levels well-correlated with those of the NESID indicator. Influenza positivity in the NHO data, however, showed an earlier rise and peak time compared to the NESID indicator. Importantly, through the non-epidemic summer periods and the coronavirus disease 2019 pandemic, a sizable number of influenza tests continued to be done at NHO hospitals, with results showing considerably low case counts and test positivity. These data show that a relatively small number of sentinel sites is sufficient to monitor influenza activity nationally, and, that utilizing multiple indicators can increase our confidence in situational awareness and data interpretations.

The administration of high-dose clindamycin (CLI) along with penicillin is recommended for the treatment of streptococcal toxic shock syndrome (STSS). However, CLI-resistant strains have been identified worldwide. Firstly, in this study, some CLI-resistant strains showed increased extracellular activities of the NAD- glycohydrolase (NADase) exotoxin after CLI treatment. This result supported our previous conclusion that not only CLI-susceptible but also CLI-resistant S. pyogenes strains show the CLI-dependent NADase induction. Secondary, using the 13 types of two- component-sensor knockout strains derived from a CLI-susceptible strain 1529 that has the CLI-dependent NADase induction phenotype, we investigated the mechanism of action. Among the knockout strains, only 1529ΔcovS lost the phenotype. In addition, 1529ΔspeB, 1529Δmga, and 1529Δrgg retained the CLI-dependent NADase induction phenotype. These results suggest that CovS is related to the phenotype in SpeB independent manner.

The Japanese guidelines for the management of Clostridioides difficile infection (CDI) recommend metronidazole (MNZ) for non-severe cases and vancomycin (VCM) for severe cases. Here, we investigated the use of CDI antimicrobials and evaluated their clinical efficacy in four severity classifications and the validity of these classifications. A retrospective chart review was conducted on 137 inpatients with an initial positive C. difficile toxin test and initiation of CDI antimicrobials between April 2015 and March 2019. For the clinical efficacy analysis of the CDI antimicrobials and validation of the severity classifications, patients treated with VCM or oral MNZ were included. The endpoints were CDI recurrence rate, 30-day mortality rate, and diarrhea cure rate. No significant differences were found between the VCM and oral MNZ groups regarding the CDI recurrence rate (10.4% vs. 12.7%, p = 0.707), 30-day mortality rate (12.5% vs. 5.6%, p = 0.162), and diarrhea cure rate (61.9% vs. 72.7%, p = 0.238), regardless of the severity. Treatment with oral MNZ for non-severe cases was promising, confirming the usefulness of treatment according to Japanese guidelines. Further investigation of the clinical efficacy of oral MNZ in patients with first-episode CDI and evaluation of the preferable severity classification are warranted.

Respiratory samples from 139 hospitalized children were screened for the Human Bocavirus (HBoV) genome. Positive samples were sequenced for partial VP1/VP2 gene followed by molecular and phylogenetic analyses. HBoV positivity was noted in 7.2% (10/139) patients. All HBoV positive children presented with fever followed by cough and respiratory distress (90%; 9/10). Three children developed multisystemic viral illness with one fatality. Eight children required intensive care management and mechanical ventilation required for 5 children. Nucleotide percent identity of partial VP1/VP2 gene of HBoV study strains were ranging from 97.52% to 99.67%. Non-synonymous amino acid mutations in VP1 protein revealed T591S (n=8) and Y517S (n=1) mutations in comparison to HBoVSt1 strain where N475S (n=8) and S591T (n=2) mutations in comparison to HBoVSt2 strain. One study strain showed A556P, H556P, I561S and M562R non-synonymous mutations. All the study strains belong to HBoV1 type. Seven HBoV strains belong to same lineage and three belong to another lineage. For evolutionary dynamics, GTR+I substitution model with uncorrelated relaxed lognormal clock and Bayesian Skyline tree prior showed 9.0 x 10^-4 [95% HPD interval: 3.1 x10^-6, 2.1 x 10^-3] nucleotide substitutions/site/year. The clinical suspicion and virological screening is necessary for identification HBoV in children.

Acquired immune deficiency syndrome (AIDS) is susceptible to numerous complications such as sepsis and acute kidney injury (AKI), leading to adverse outcomes. Continuous renal replacement therapy (CRRT) is becoming increasingly popular in the treatment of sepsis and AKI. This study aimed to verify the effectiveness of CRRT in the treatment of AIDS with sepsis and AKI, to provide new directions for the treatment of severe AIDS. Data of 74 people with AIDS, sepsis and AKI were collected. They were divided into CRRT and non-CRRT groups. There was no difference in indicators between the two groups at admission. Vital signs, PH, serum potassium, renal function, blood lactate, APACHE II score, and SOFA score in CRRT group demonstrated significant improvements over those in the non-CRRT group both 24 and 72 hours after admission (P＜0.05). Level of Interleukin 6 and procalcitonin declined more significantly in CRRT group 72 hours after admission (P＜0.05). CRRT group had a higher 28-day survival rate (P＜0.05). CRRT improves the clinical indicators and increases the short-term survival rate of people with AIDS, sepsis and AKI.

The patient was a 22-year-old woman with no comorbidities who was transferred to our hospital due to cardiac arrest. Treatment enabled return to spontaneous circulation in the patient before arriving at the hospital. At the hospital, the patient’s vital signs were unstable. Vasopressors and hyperhydration therapy were administered. Computed Tomography (CT) showed no remarkable change that caused the cardiac arrest. Antibiotics were prescribed after a blood culture exam. The patient was admitted to the ICU. In the ICU, the high-capacity vasopressors, hyperhydration therapy and transfusion of fresh frozen plasma were continued. Two hours after examining the blood culture, the results remained positive. Gram staining revealed Streptococcus, and the antibiotics were switched to penicillin G potassium, clindamycin and immunoglobulin was added. Hyperhydration therapy caused respiratory failure. Ten hours after admission to the ICU, extracorporeal membrane oxygenation was introduced, but the patient’s general status did not improve. The patient died at 40 hours after admission. Blood culture results proved Streptococcus pyogenes; T and M serotypes were unclassifiable. The emm genotype was emm22. Regarding fever toxin genes, speA and speB were positive, and speC was negative. Among CsrS, CsrR and Rgg amino acid sequences, mutations in CsrS were detected.

We herein report the first case of necrotizing fasciitis caused by Pigmentibacter ruber. The isolated strain could not be identified by biochemical characterization and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The isolated strain was identified as P. ruber by 16S ribosomal RNA and whole genome sequencing. Although much remains unknown about the pathogenicity of this bacterial specie in humans, it has been revealed to cause life-threatening infections, such as septicemia and necrotizing fasciitis. Since the isolate was highly resistant to beta-lactams, it could be difficult to treat with antimicrobial therapy. Thus further documentation of cases and analyses are needed.

Escherichia coli is a Gram-negative bacterium that prominently causes a variety of clinical infections in humans, such as diarrhea, sepsis, and urinary tract infection. This bacterium is a common multidrug-resistant threat in community and hospital settings worldwide. This study examined the antimicrobial susceptibility and genetic relationship based on Clermont phylotyping and ERIC-PCR of 84 E. coli urinary isolates from provincial and community hospitals in Thailand. All the isolates were completely susceptible to nitrofurantoin, whereas almost all isolates were susceptible to carbapenem, fosfomycin, and amikacin. A high resistance rate was found to fluoroquinolone, ampicillin, and trimethoprim/sulfamethoxazole. Clermont phylogroup B2 was predominant (n=58). Subtyping of the B2 phylogroup revealed diverse subgroups, of which subgroup V (n=11) was predominant, followed by VII (n=9), III (n=6), and II (n=6). ERIC-PCR showed the strain of the B2 subgroups III and V were spread between provincial and community hospitals and between hospital wards. This evidence suggested the need for comprehensive infection control monitoring, with strong active surveillance at all hospital levels.

The association between proton-pump inhibitor (PPI) use and systemic infections caused by bacterial translocation is unclear. This study aims to investigate whether patients receiving PPI therapy have a higher risk for bloodstream infections (BSI) without an identifiable source of infection, as an alternative indicator of BSI secondary to bacterial translocation. We conducted a hospital-based case–control study which enrolled all patients aged 20 years and older who developed BSI confirmed by two sets of positive blood culture and had inpatient care in Ichinomiya-Nishi Hospital in 2019. Patients’ data were collected from medical records, and bacterial translocation type (BT-type) BSI group were defined as those who had BSI without an identifiable source of infection, whereas the others were classified control group based on the diagnostic criteria for each infectious disease. We analyzed data from 309 patients, including 66 cases and 243 controls. PPI users had a 2.4-fold higher risk of developing BT-type BSI compared to non-PPI-users after controlling for potential confounders (OR: 2.41, 95% CI: 1.29–4.51, p=0.006). In conclusion, PPI use is associated with higher risk of BSI without an identifiable source and therefore, PPI use may increase the risk of septic morbidity secondary to bacterial translocation.

All clinical isolates of Streptococcus dysgalactiae subsp. equisimilis (SDSE) are considered susceptible to β-lactams, the first-line drugs used for SDSE infections. However, penicillin-non-susceptible SDSE has been reported from Denmark. In this study, we attempted to detect β-lactam-non-susceptible clinical isolates of SDSE in Japan. One hundred and fifty clinical isolates of S. dysgalactiae were collected in 2018, and species identification was performed using Rapid ID Strep API. The minimum inhibitory concentrations (MIC) of six β-lactams (penicillin G, oxacillin, ceftizoxime, ceftibuten, cefoxitin, and cefaclor) were determined for 85 clinical isolates of SDSE using the agar dilution method standardized by the Clinical Laboratory Standards Institute. For the 85 isolates identified as SDSE, the MIC ranges of penicillin G, oxacillin, ceftizoxime, ceftibuten, cefoxitin, and cefaclor were 0.007–0.06, 0.03–0.12, 0.015–0.06, 0.25–2, 0.12–2, and 0.06–0.5 μg/mL, respectively. None of the clinical isolates were non-susceptible to penicillin G, indicating that all 85 clinical isolates of SDSE were susceptible to β-lactams. Our findings indicate that almost all clinical isolates of SDSE in several prefectures of Japan remain susceptible to β-lactams. Nevertheless, there remains a need for continuous and careful monitoring of drug susceptibility among clinical isolates of SDSE in Japan.

Since 2019, many studies on COVID-19, which has caused extensive damage as a pandemic, have been ongoing worldwide. These include serological and biochemical studies using sera from patients and animal models. Testing with these sera must be performed after the inactivation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Heat treatment, UV irradiation, and/or gamma-ray irradiation are used to inactivate viruses in serum. Determining the inactivation conditions that ensure the inactivation of viruses and minimize the effect on test results after inactivation is important to ensure worker safety and accuracy of test results. In this study, serum samples containing SARS-CoV-2 were subjected to heat, UV irradiation, and gamma irradiation to determine their inactivation conditions. The viral titers were below the detection limit after heating at 56°C for 1 h or 60°C for 15 min, UV-B irradiation with a transilluminator for 30 min, or gamma ray irradiation with ⁶⁰Co at 10 kGy. These results provide useful information for safe serological and biochemical experiments.

Stenotrophomonas maltophilia is a non-fermenting Gram-negative drug-resistant pathogen causing healthcare-associated infections. Clinical isolates from Mexico were assessed for biofilm production by crystal violet staining. Antimicrobial susceptibility was evaluated using the broth microdilution method in planktonic and biofilm cells. The effect of antibiotics on the biofilm was visualized by fluorescence microscopy. Fifty isolates were included in the study, of which 28.0% were biofilm producers (64.2% from blood and 35.7% from respiratory samples). Resistance to levofloxacin (8.0%) and trimethoprim-sulfamethoxazole (44.0%) in planktonic cells increased to 100% in biofilm cells. Bacterial biofilm treated with several concentrations of both antibiotics was completely disrupted. In conclusion, S. maltophilia isolated from blood had higher biofilm production than those from respiratory samples. Resistance to antibiotics increased due to biofilm production. Antibiotic monotherapy might not be the best course of action for the treatment of S. maltophilia infections in Mexico, as they might also be causing biofilm production.