Japanese journal of infectious diseases最新文献

Guidelines for sexually transmitted infections recommend oral metronidazole (MNZ) as the first-line treatment option for vaginal trichomoniasis; however, there have been cases of prolonged symptoms or recurrence after treatment. To consider appropriate treatment strategies for refractory vaginal trichomoniasis, we conducted a retrospective cohort study. We reviewed the medical records of patients who tested positive for Trichomonas vaginalis (T. vaginalis) at the National Center for Global Health and Medicine between August 2011 and May 2023. Refractory vaginal trichomoniasis was defined as the failure after the initial MNZ treatment. During the study period, nine cases of vaginal trichomoniasis were identified, six of which were refractory to treatment for T. vaginalis. Four patients were cured with a combination of oral and vaginal tinidazole (TNZ) therapy, one with oral TNZ and one with two doses of MNZ. Possible causes of treatment failure include MNZ-resistant T. vaginalis, reinfection between partners, and infections of other sexual transmitted diseases. However, the fact that TNZ was effective suggests that MNZ-resistant T. vaginalis may have been the cause. Although MNZ resistance testing was not performed in this study, treatment with TNZ should be considered in cases of refractory vaginal trichomoniasis, possibly caused by MNZ-resistant T. vaginalis.

Japan's National Epidemiological Surveillance of Infectious Diseases (NESID) has implemented a warning system for detecting epidemics in smaller districts, such as public health center (PHC) areas. This system is applied to influenza and pediatric infectious diseases but not to respiratory syncytial virus (RSV) infection, whose incorporation is essential for early epidemic detection. We aimed to propose criterion values for the epidemic warning system of RSV infection within PHC areas. We analyzed the weekly number of RSV infection cases reported by sentinel medical institutions (SMIs) in the NESID from 2015 to 2019. Weekly cases per SMI in the PHC area were set for an index for epidemic warnings. We determined the criteria for issuing an epidemic warning by describing the percentiles of the distribution of the index. Setting the critical values for the onset and end of the epidemic warning at 5 and 2, respectively, yielded an approximately 5% annual proportion of PHC areas with an epidemic warning. This aligns with the acceptably implemented frequency of epidemic warnings. The 5-year (2015-2019) RSV infection epidemic trend showed that the set critical values were appropriate. Using these values could help issue warnings regarding potential RSV infection epidemics in Japan.

Evidence about which types of mask are effective in preventing infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is limited. We examined which mask types were effective against SARS-CoV-2 infection in a cluster setting in Japan. We retrospectively reviewed data from a cluster of COVID-19 cases that occurred at a manufacturing company in mid-August 2021. We included a total of 87 individuals who reported the type of mask worn. We dichotomized the types of mask into non-woven masks or other types of mask, such as cloth or urethane masks. We then examined the associations between the mask type and SARS-CoV-2 infection using logistic regression analysis, adjusting for potential confounders. Participants who wore non-woven masks were less likely to be infected with SARS-CoV-2 (9.7%) compared with those who wore other types of mask (26.7%). After adjusting for potential confounders, wearing a non-woven mask was significantly associated with a reduced risk of infection compared with wearing other mask types (odds ratio = 0.10, 95% confidence interval: 0.01 to 0.80). Non-woven masks were found to be more effective in preventing SARS-CoV-2 infection in a cluster setting than other types of mask, such as cloth or urethane masks.

Immunofluorescence methods to detect seasonal human coronavirus (HCoV)-OC43 in nasopharyngeal swab specimens using cell lines have not yet been established. A human rectal adenocarcinoma cell line (HRT-18) was exposed to the specimens obtained from patients with upper respiratory tract infections. Immunofluorescence staining was conducted with the combination of human serum containing the HCoV-OC43 anti-spike protein antibody and a fluorescence-labeled anti-human antibody. Positive staining in HRT-18 cells was detected after exposure to specimens obtained from nine of the eleven patients in which HCoV-OC43 RNA was detected using the FilmArray method. Increased supernatant viral RNA levels were also detected in HRT-18 cells exposed to specimens obtained from four of five patients. In contrast, positive staining was not detected in HRT-18 cells exposed to six patient specimens that tested negative for RNA from seventeen types and subtypes of respiratory viruses, including HCoV-OC43. The cells inoculated with the established strain HCoV-OC43 (ATCC VR-759) also showed positive staining. These findings suggest that the replication-competent HCoV-OC43 in the specimens could be detected via immunofluorescence staining of HRT-18 cells with human serum. It may be possible to obtain positive staining for viruses other than HCoV-OC43 using this method.

Getah virus (GETV), belonging to the genus Alphavirus within the family Togaviridae, is a mosquito-borne virus that causes fever, rash, and edema in horses and fatalities and pregnancy disorders in pigs. It has caused occasional outbreaks in horse populations in Japan, China, and India, and endemic areas are gradually expanding, particularly in Asia and Oceania. In this study, we isolated a new GETV strain from Culex tritaeniorhynchus mosquitoes collected from Nagasaki Prefecture, Japan in 2022. Phylogenetic analysis revealed that this new strain, 22IH8, is more closely related to previous Chinese strains than to the strains prevalent in Japan in the 2010s. Furthermore, some amino acid substitutions in the viral proteins of strain 22IH8 were found to be common with those in previous Chinese strains. These results suggest that 22IH8 strain may have recently invaded the Japanese archipelago from mainland Asia. The antiserum against the current vaccine strain, MI-110, showed high neutralization activity against the 22IH8 strain indicating the efficiency of the current vaccine for horses in Japan.

While a live-attenuated Yellow fever (YF) vaccine is known to elicit durable immunity, antibody titers may wane after vaccination. This study evaluated the long-term immunity after vaccination against YF among individuals who reside in Korea and received vaccination with YF virus-17D prior to international travel. Serum was collected between December 2018 and December 2019 at the National Medical Center, Republic of Korea from YF vaccine recipients who were vaccinated more than five years prior to sample collection. Long-term immunity against YF was assessed using three serological assays: IgG enzyme-linked immunosorbent assay (ELISA), immunofluorescence assay (IFA), and focus reduction neutralization test (FRNT). Sixty seven subjects were enrolled. The overall positivity rates for FRNT₅₀, IFA and ELISA were 97.0%, 86.6% and 26.9%, respectively, in a time-variable, cross-sectional sample of the cohort. While 93.8% (15/16) of samples collected ≥10 years post-vaccination remained positive by FRNT₅₀, a significant inverse correlation was observed between FRNT₅₀ titer and interval after vaccination (r=-0.385, p=0.001). Humoral immunity against YF was well preserved among the Korean individuals who were more than five years post-vaccination. IFA testing yielded results similar to FRNT₅₀ testing, which may justify further development of the IFA to screen for waning immunity among those with previous YF vaccination.

The effect of antibodies elicited by bivalent mRNA vaccines (original and omicron BA.1) on preventing coronavirus disease 2019 (COVID-19) onset in the presence of the XBB variant remains unknown. A prospective cohort study conducted at Chiba University Hospital examined healthcare workers who received their sixth vaccination with the Pfizer-BioNTech COVID-19 bivalent mRNA vaccine (original and omicron BA.1). Researchers quantitatively measured serum anti-spike (S) antibody levels. Participants not infected during the 60-day observation period after vaccination had significantly higher S antibody titers than those who were newly infected (27756 U/mL, 95% CI [24988-30831 U/mL] vs. 15321 U/mL, 95% CI [10824-21688 U/mL], p<0.05). The risk of infection decreased by 84% when the S antibody titer exceeded 15500 U/ml. Neutralizing antibody titers against the XBB.1.16 and XBB.1.42 variants were higher in age- and sex-matched noninfected individuals than in newly infected individuals during the post-vaccination observation period. S antibody titers were highly correlated with neutralizing antibody titers. In conclusion, after the sixth COVID-19 vaccination with the bivalent mRNA vaccine (original and omicron BA.1), high S antibody titers correlated with disease prevention, even in the presence of XBB variants.

In 2021, vaccines against SARS-CoV-2 were developed, and the Omicron variant emerged. This study compared the characteristics, treatments, and mortality of patients with coronavirus disease 2019 (COVID-19) between 2022 and 2020-2021, using administrative claims data linked with vaccine records in a Japanese city. We identified patients underwent COVID-19 antigen or polymerase chain reaction tests and were diagnosed with COVID-19. Patient characteristics, treatments, and mortality were compared between 2022 and 2020-2021 among those diagnosed with COVID-19 and those who died. We identified 26,262 patients with COVID-19. The mortality in 2022 was lower than that in 2020-2021 (0.6% vs. 1.7%; P<0.01). Patients in 2022 were significantly less likely to receive oxygen therapy, high-flow nasal oxygenation, mechanical ventilation, steroid, or tocilizumab than those in 2020-2021. Among the deceased, the proportion of those aged ≥65 years was significantly higher in 2022 than in 2020-2021 (98.4% vs. 88.6%). On logistic regression, older age, male, and ≥3 comorbidities were associated with higher mortality, whereas ≥3 vaccinations were associated with lower mortality. Patients with COVID-19 in 2022 were less likely to require respiratory care or succumb to the disease. Older patients were more likely to die in 2022 than in 2020-2021.

A previously healthy 22-year-old woman was admitted to our hospital after an out-of-hospital cardiac arrest. Spontaneous circulation was restored prior to arrival at the hospital. However, the patient's vital signs remained unstable. Vasopressors and hyperhydration therapy were administered. Computed tomography did not reveal a cause of the cardiac arrest. Antibiotics were initiated after obtaining blood culture samples. The patient was admitted to the intensive care unit (ICU). High-dose vasopressors and hyperhydration therapy were continued and fresh frozen plasma was transfused. Two hours after ICU admission, gram staining of a blood smear revealed the presence of Streptococcus, and the antibiotics were switched to penicillin G potassium and clindamycin, and immunoglobulins were administered. Extracorporeal membrane oxygenation was initiated 10 h after ICU admission owing to respiratory failure caused by fluid overload; however, the patient's condition did not improve and she died 40 h after admission. Blood culture results confirmed the presence of Streptococcus pyogenes; the T and M serotypes were unclassifiable. The emm genotype was emm22. Sequencing revealed the presence of streptococcal pyrogenic toxin genes, speA and speB, whereas speC was absent. CsrS, CsrR, and Rgg amino acid sequencing revealed the presence of a CsrS mutation.

Persistent inflammation during chronic human immunodeficiency virus (HIV) infection may affect the immune response against severe acute respiratory syndrome-coronavirus 2 (SARS- CoV-2) infection. Plasma levels of multiple proinflammatory cytokines during acute SARS-CoV-2 infection were measured in people with HIV (PWH) with effective combination antiretroviral therapy. There were no significant differences in any of the measured cytokines between severity levels of coronavirus disease 2019 (COVID-19) in PWH, while most were significantly higher in HIV-uninfected individuals with severe COVID-19, suggesting that excess cytokines release by hyperinflammatory responses do not occur in individuals with severe COVID-19 with HIV infection. The strong associations between the cytokines observed in HIV-uninfected individuals, particularly between IFN-α/TNF-α and other cytokines, were lost in PWH. The steady-state plasma levels of IP-10, ICAM-1, and CD62E were significantly higher in PWH, indicating that they were in an enhanced inflammatory state. The absence of several inter-cytokine correlations was observed in in vitro lipopolysaccharide stimulus-driven cytokine production in PWH. These data suggest that inflammatory responses during SARS-CoV-2 infection in PWH are distinct from those in HIV-uninfected individuals, partially because of the underlying inflammatory state and/or impairment of innate immune cells.