Japanese Journal of Infectious Diseases
Online ISSN : 1884-2836
Print ISSN : 1344-6304
ISSN-L : 1344-6304
Volume 77, Issue 5
Displaying 1-10 of 10 articles from this issue
Original Articles
Original Article
  • Ichiro Tatsuno, Masanori Isaka, Tadao Hasegawa
    2024 Volume 77 Issue 5 Pages 247-252
    Published: September 30, 2024
    Released on J-STAGE: September 19, 2024
    Advance online publication: March 29, 2024
    JOURNAL FREE ACCESS

    Administration of high-dose clindamycin (CLI) and penicillin is recommended for the treatment of streptococcal toxic shock syndrome (STSS). However, CLI-resistant strains have been identified worldwide. In this study, some CLI-resistant strains demonstrated increased extracellular activity of the NAD-glycohydrolase (NADase) exotoxin following CLI treatment. These results support our previous conclusion that CLI-susceptible and CLI-resistant Streptococcus pyogenes strains exhibit CLI-dependent NADase induction. Furthermore, we investigated the mechanism of this phenomenon using 13 types of two-component sensor knockout strains derived from the CLI-susceptible strain 1529 that has a CLI-dependent NADase induction phenotype. Among the knockout strains, only 1529ΔcovS lost the phenotype. Additionally, 1529ΔspeB, 1529Δmga, and 1529Δrgg retained the CLI-dependent NADase induction phenotype. These findings indicate that CovS is related to this phenotype in a SpeB-independent manner.

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  • Hilary Osaka, Yasuaki Tagashira, Hiroaki Takeuchi, Yukie Tanaka, Kousu ...
    2024 Volume 77 Issue 5 Pages 253-259
    Published: September 30, 2024
    Released on J-STAGE: September 19, 2024
    Advance online publication: May 31, 2024
    JOURNAL FREE ACCESS

    Clusters of nosocomial coronavirus disease 2019 (COVID-19) have been reported globally during the recent pandemic. Unfortunately, these clusters negatively affect inpatient morbidity, mortality, and hospital functioning. Using epidemiological data and whole-genome sequencing (WGS) of SARS-CoV-2, this study investigated the outbreak of COVID-19 at a university hospital. Eight inpatients and 13 healthcare workers tested positive for SARS-CoV-2 during a 1-month period. WGS of the virus in 11 patients revealed that the two variants of concern belonging to the Omicron sublineages, BA.2.3 and BA1.1.2, caused an outbreak when the proportion of the Omicron lineage in the community changed. When variants of concern undergo 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. Awareness of infection prevention and control should be raised to safeguard patient safety.

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  • Humberto Antonio Salazar-Sesatty, Edeer Iván Montoya-Hinojosa, Verónic ...
    2024 Volume 77 Issue 5 Pages 260-268
    Published: September 30, 2024
    Released on J-STAGE: September 19, 2024
    Advance online publication: May 31, 2024
    JOURNAL FREE ACCESS

    Biofilm-producing methicillin-resistant Staphylococcus aureus (MRSA) and coagulase-negative staphylococci (MR-CoNS) pose clinical challenges in treating healthcare-associated infections. As alternative antimicrobial options are needed, in this study, we aimed to determine the effect of curcumin-chitosan magnetic nanoparticles (Cur-Chi-MNP) on the biofilms of staphylococcal clinical isolates. MRSA and CoNS clinical isolates were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Antimicrobial susceptibility testing was performed using the broth microdilutions. Nanoparticles were synthesized by the co-precipitation of magnetic nanoparticles (MNP) and encapsulated by the ionotropic gelation of curcumin (Cur) and chitosan (Chi). Biofilm inhibition and eradication by nanoparticles, with and without the addition of oxacillin (OXA), were assessed in Staphylococcus strains. Cur-Chi-MNP showed antimicrobial activity against planktonic cells of MRSA and MR-CoNS strains and inhibited MRSA biofilm. The addition of OXA to Cur-Chi-MNP increased the biofilm inhibition and eradication activity against all staphylococcal strains (P = 0.0007), and higher biofilm activity was observed in the early biofilm stages. Cur-Chi-MNP showed antimicrobial and biofilm inhibitory activities against S. aureus. Addition of OXA increased biofilm inhibition and eradication activity against all staphylococcal strains. A combination treatment of Cur-Chi-MNP and OXA could potentially be used to treat staphylococcal biofilm-associated infections in the early stages before the establishment of biofilm bacterial cells.

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  • Isabela Faria, Rita Facão, Filipa Murta, Rúben Carvalho, Carla Silva, ...
    2024 Volume 77 Issue 5 Pages 269-273
    Published: September 30, 2024
    Released on J-STAGE: September 19, 2024
    Advance online publication: May 31, 2024
    JOURNAL FREE ACCESS

    Chronic hepatitis C (CHC) is a serious condition of public health importance. In Portugal, the prevalence of detectable hepatitis C virus (HCV) antibodies is approximately 0.54%, with a higher prevalence in high-risk groups. Compared with the general population, the prevalence of HCV infection is higher in individuals with psychiatric disorders. As no studies have reported the prevalence of HCV antibodies in Portuguese patients with psychiatric conditions and substance use disorders, we conducted an observational, prospective study of patients followed in the Dual Pathology Outpatient and Inpatient Unit of Coimbra Hospital and University Center (CHUC), Patients were tested for HCV antibodies. Of the 149 patients, 17.4% were positive for HCV antibodies and 7.4% had detectable HCV RNA indicating CHC. Most patients with confirmed CHC were male inpatients, aged 50 to 59 years, and reported unprotected sex with more than one concurrent partner in the past 6 months. Their most common psychiatric diagnosis was “Disorders due to use of multiple specified psychoactive substances, including medications.” The prevalence of HCV antibodies and confirmed CHC were higher in patients followed in the Dual Pathology Outpatient and Inpatient Unit than in the general Portuguese population.

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  • Yukari Murata, Atsushi Yoshida, Eriko Suzuki, Asamoe Ogawa, Konomi Mur ...
    2024 Volume 77 Issue 5 Pages 274-280
    Published: September 30, 2024
    Released on J-STAGE: September 19, 2024
    Advance online publication: May 31, 2024
    JOURNAL FREE ACCESS

    In recent years, the incidence of syphilis in Tokyo has increased. This descriptive epidemiological study aimed to elucidate the status of syphilis within the city. Data regarding age, sex, disease stage, and presumed sexual partners of patients with syphilis reported in Tokyo were compiled and analyzed. A total of 9,419 patients with syphilis were diagnosed between 2019 and 2022. A sharp rise was observed in the number of reported cases from 2021 to 2022. Between 2020 and 2022, the number of women in their 20s who developed syphilis rapidly increased by more than 3-fold. Furthermore, the number of pregnant women with syphilis increased the end of 2022. Despite a rapid increase in the number of young women with syphilis, the incidence of congenital syphilis has remained stable. This stability may be attributed to the early detection of syphilis during pregnancy, facilitated by the high rate of antenatal checkups in Tokyo. However, the growing incidence of syphilis among young women could potentially lead to a rise congenital syphilis cases in the future. Therefore, public health strategies should include educational initiatives targeting high-risk populations and adolescents, along with early and appropriate testing and treatment to prevent the progression of syphilis.

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Short Communications
Short Communication
  • Mariko Ohtani, Sadako Yoshizawa, Taito Miyazaki, Eri Kumade, Shinobu H ...
    2024 Volume 77 Issue 5 Pages 281-284
    Published: September 30, 2024
    Released on J-STAGE: September 19, 2024
    Advance online publication: March 29, 2024
    JOURNAL FREE ACCESS

    Japanese guidelines recommend metronidazole (MNZ) and vancomycin (VCM) for non-severe and severe cases of Clostridioides difficile infection (CDI), respectively. In the present study, we investigated the use of CDI antimicrobials and evaluated their clinical efficacy and validity using four severity classifications. A retrospective chart review was conducted using the data of 137 inpatients with initially positive C. difficile toxin test results and the initiation of CDI antimicrobials between April 2015 and March 2019. Patients treated with VCM or oral MNZ were included for clinical efficacy analysis of CDI antimicrobials and validation of severity classifications. The endpoints were CDI recurrence, 30-day mortality, and diarrhea cure rates. No significant differences were found between the VCM and oral MNZ groups in 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 severity. Treatment with oral MNZ for non-severe cases was promising, confirming its usefulness according to Japanese guidelines. Further investigation of the clinical efficacy of oral MNZ in patients with first-episode CDI and evaluation of the preferred severity classification are warranted.

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  • Chang Kyung Kang, Youngju Kim, Hyeon Jae Jo, Chan Mi Lee, Nam Joong Ki ...
    2024 Volume 77 Issue 5 Pages 285-288
    Published: September 30, 2024
    Released on J-STAGE: September 19, 2024
    Advance online publication: April 30, 2024
    JOURNAL FREE ACCESS

    The accurate identification of individuals without prior infection with severe acute respiratory syndrome coronavirus 2 is pivotal for seroepidemiological studies and vaccine trials. Owing to widespread vaccination against coronavirus disease 2019 (COVID-19), 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 three years earlier. We enrolled 44 participants with laboratory-confirmed COVID-19 between January and May 2020 from the Seoul National University Hospital and its community treatment centers. The results showed anti-nucleocapsid antibody positivity ranging from 45.5% to 87.9%, depending on the immunoassay. This study highlights the importance of considering the limited anti-nucleocapsid antibody positivity in individuals, with a history of distant COVID-19, in seroepidemiological or vaccine research.

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  • Jinxia Su, Shunguang Li, Morui Chen, Zewei Huang, Huijun Liu, Pinghua ...
    2024 Volume 77 Issue 5 Pages 289-291
    Published: September 30, 2024
    Released on J-STAGE: September 19, 2024
    Advance online publication: April 30, 2024
    JOURNAL FREE ACCESS

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

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  • Mei Koyama, Satoshi Hiroi, Yuki Hirai, Atsushi Kaida
    2024 Volume 77 Issue 5 Pages 292-295
    Published: September 30, 2024
    Released on J-STAGE: September 19, 2024
    Advance online publication: May 31, 2024
    JOURNAL FREE ACCESS

    The incidence and type distribution of human adenovirus (HAdV) infections among children with pharyngoconjunctival fever (PCF) in Osaka, Japan between 2019 and 2023 were analyzed to assess the effect of the coronavirus disease 2019 (COVID-19) pandemic. 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 detected in throughout the study period. Conversely, HAdV-B3 was not detected for 2 years and 9 months from March 2020 to December 2022, but the number of detections increased from July 2023. Overall, HAdV-B3 was the most frequently detected type (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 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 that children were susceptible owing to a lack of exposure to HAdV-B3 between 2020 and 2022. Ongoing surveillance is needed to evaluate the impact of COVID-19 on the prevalence of HAdV infection.

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Epidemiology Communication
  • Takeshi Arashiro, Yuzo Arima, Takuri Takahashi, Kiyosu Taniguchi, Hiro ...
    2024 Volume 77 Issue 5 Pages 296-300
    Published: September 30, 2024
    Released on J-STAGE: September 19, 2024
    Advance online publication: March 29, 2024
    JOURNAL FREE ACCESS

    In Japan, based on the National Epidemiological Surveillance of Infectious Diseases (NESID) Program, influenza cases from approximately 5,000 sentinel sites are monitored weekly as part of influenza surveillance (as the number of influenza cases per sentinel site). One limitation is that the number of influenza tests conducted is not reported. However, the National Hospital Organization (NHO), with approximately 140 hospitals, routinely publishes three indicators: the number of influenza tests, the number of influenza-positive cases, and test positivity. We used the NESID and NHO data from April 2011 to June 2022 to assess the usefulness of multiple indicators for monitoring influenza activity. The temporal trends of the NHO and NESID indicator were similar, and the NHO indicator levels correlated well with those of the NESID indicators. However, influenza positivity in the NHO data showed an earlier rise and peak time than that in the NESID indicator. Importantly, during the non-epidemic summer periods and the coronavirus disease 2019 pandemic, a sizable number of influenza tests were still performed 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.

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