Herein, we report the interim vaccine effectiveness (VE) of a quadrivalent inactivated influenza vaccine, during the 2019/2020 influenza season, in Japan. We conducted a retrospective observational cohort study of 381 patients aged ≥15 years, who were enrolled with influenza like illnesses and examined via the rapid influenza diagnostic test, at the Ambulatory Care unit of the National Center for Global Health and Medicine in Tokyo, Japan, from the beginning of October 2019 to the end of January 2020. VE was estimated using a test-negative design. VE was calculated as (1 – odds ratio) × 100%, comparing influenza A test positivity between vaccinated and unvaccinated patients. Of the 381 patients initially screened for inclusion, 314 were enrolled in the study. Of these, 105 were vaccinated, 98 were diagnosed with influenza A, and 5 were diagnosed with influenza B. Overall VE against influenza A was 27.6% (95% confidence interval [CI], ‒21.1 to +57.4), and in patients aged ≥65 years, it was 47.3% (95% CI, ‒76.0 to +86.0). This indicates that the influenza vaccination offered continued protection during the 2019/2020 influenza season, but a detailed analysis of more cases with a careful consideration of methodology is necessary to estimate VE more precisely.

Acanthamoeba are free-living amoebae that cause granulomatous amoebic encephalitis and keratitis. In this study, we aimed to isolate and identify Acanthamoeba from air conditioning systems using in vitro cell culture and polymerase chain reaction assays. We also estimated the pathogenicity of the isolates by measuring their thermotolerance and studying mice models inoculated with these isolates. Of the 80 dust samples acquired, 41 (51.25%) were found to be positive for Acanthamoeba spp. using in vitro cell culture and the results were validated using PCR. Out of these 41 samples, 27 (65.9%) were thermotolerant and 16 (39%) samples could infect mice and cause histopathological effects. Highly pathogenic Acanthamoeba isolates were characterized by their thermotolerance and the ability to disseminate in all organs after infection, causing early death of infected animals. Our study thus validated the presence of pathogenic isolates of Acanthamoeba in air conditioners that may be potentially infectious to humans.

Routine vaccination has proven to be highly effective in reducing the incidence of mumps. However, sporadic cases and/or mumps outbreaks have been reported in children and adolescents younger than 15 years of age, particularly among those aged 5–9 years. To explore the characteristics of such outbreaks in the Henan Province, clinical data of patients infected with mumps virus (MuV) were collected, and the isolated strains were phylogenetically analyzed. Of the total 426 samples analyzed, MuV RNA targeting the small hydrophobic (SH) gene was detected in 153 samples. MuV-positive cases in age groups <5 years, 5–9 years, 10–15 years, 16–19 years, and ≥20 years accounted for 1%, 17%, 12%, 2%, and 4% of the total number of cases, respectively. Phylogenetic analysis based on the SH gene sequences indicated that all of the isolated strains were of genotype F, and isolates in the same subcluster and with identical SH gene sequences tended to be derived from the same community or municipalities when analyzed alongside epidemiological data. In conclusion, the incidence of mumps in the Henan Province was high. The data provided in this study might promote further research in the clarification of the specific causes of mumps outbreaks, which can facilitate the implementation of effective prevention and control measures.

The quadrivalent meningococcal polysaccharide diphtheria toxoid conjugate vaccine (Men-ACWY-D) has been licensed for use in Japan since 2014. An earlier registration study demonstrated the immunogenicity of a single dose in Japanese adults, wherein the immunogenicity against serogroup C was the lowest. The determination of the potential to increase the serogroup C response with a second dose was, therefore, of interest. This study (NCT02591290) evaluated the safety and immunogenicity of two doses administered 8 weeks apart to 60 healthy Japanese adults aged 20–55 years. Blood samples were collected at 28–35 days after vaccination. Immunogenicity endpoints included seroprotection and seroconversion rates. Safety assessments included systemic adverse events (AEs), non-serious AEs, and serious AEs. Fifty-eight participants (96.7%) completed the study. The seroprotection rates for serogroups A, C, W, and Y before vaccination were 76.8%, 26.8%, 26.8%, and 50.0%, respectively, increasing to 100%, 83.9%, 91.1%, and 96.4% and 100%, 92.9%, 94.6%, and 94.6%, respectively, after two doses. The seroconversion rates for the four serogroups were 100%, 93.8%, 97.1%, and 94.1%, respectively, after the first dose, and 100%, 96.9%, 100%, and 100%, respectively, after the second. The increase between the doses was insignificant, and there were no safety concerns. The two-dose series was well tolerated; however, the clinical benefits of a second dose within 8 weeks seemed to be low.

We aimed to investigate the clonal relationships, common sequence types, and carbapenemase genes in 177 non-repetitive blood culture isolates of Acinetobacter baumannii collected from patients at three university hospitals in Turkey in 2016. Molecular epidemiological characteristics of the isolates were examined using pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing (MLST) (Pasteur scheme-cpn60, fusA, gltA, pyrG, recA, rplB, and rpoB). Multiplex PCR was used to investigate the carbapenemase genes, including bla_OXA-23-like, bla_OXA-24-like, bla_OXA-48-like, bla_OXA-58-like, bla_IMP, bla_VIM, and bla_NDM. PFGE genotyping yielded 92 pulsotypes with a clustering ratio of 69.7%. As per a ≥85% similarity coefficient, 159 (90.9%) isolates were found to be clonally related. The bla_OXA-23-like and bla_OXA-58-like genes were identified in 100% and 28.2% of the isolates, respectively. The bla_NDM gene was identified in two isolates. The MLST analysis included 54 isolates with different pulsotypes, and 29 sequence types (STs). Most of the isolates (n = 36) belonged to the clonal complex (CC)2, one isolate belonged to CC1, and one isolate belonged to CC164. Sixteen new STs (ST1235–ST1250) were identified. Identifying both global ST2 and a large number of new STs, revealed high genetic diversity in A. baumannii isolates in the study population.

The reported prevalence of genital Chlamydia trachomatis infection (GCTI) is much lower in low-income countries than that in high-income countries. This study surveyed the prevalence of GCTI in 456 hospitals in Shandong province, China in December 2018. Among the hospitals surveyed, antigen testing, PCR testing, and either antigen or PCR testing were available in 200 (43.9%), 88 (19.3%), and 268 (58.8%) hospitals, respectively. PCR testing was more available in tertiary hospitals than in primary and secondary hospitals (χ² = 28.560, P = 0.000). Significant differences were observed in the availability of antigen testing (χ² = 15.708, P = 0.003), PCR testing (χ² = 22.494, P = 0.000), and either antigen or PCR testing (χ² = 21.729, P = 0.000) among different types of hospitals. In 2018, 1532 cases of GCTI were reported in 99 hospitals. Tertiary hospitals reported more cases than those in primary and secondary hospitals (χ² = 24.082, P = 0.000). The distribution of different types of hospitals that reported GCTI cases was consistent with that of hospitals that provided laboratory testing for GCTI. Antigen and PCR testing were only available in 200 (43.9%) and 88 (19.3%) hospitals, respectively. The results highlighted that the availability of laboratory testing for GCTI in Shandong province was poor, suggesting that the prevalence of GCTI in the province had been sorely underestimated.

Despite the availability of anti-tuberculosis drugs, the treatment of tuberculosis has been complicated by drug-resistant tuberculosis. The early detection of drug resistance makes early treatment possible. However, the available tools are mainly for rifampicin resistance detection, and the existing isoniazid resistance detection method is expensive, highly technical, and complicated, making it unsustainable for use in developing nations. This study aimed to develop a simple, rapid, and low-cost diagnostic kit for isoniazid-resistant tuberculosis using the single-stranded tag hybridization method to target an isoniazid resistance-conferring mutation. Specificity and sensitivity were assessed using DNA extracted from 49 isoniazid-resistant and 41 isoniazid-susceptible Mycobacterium tuberculosis clinical isolates cultured in mycobacterial growth indicator tubes. Positive signals were observed on mutant and wild-type lines with 100% sensitivity and specificity compared with Sanger sequencing results. In contrast, no positive signal was observed for non-tuberculosis mycobacteria. The detection limit of this method was 10³ CFU or less. The STH-PAS system for isoniazid-resistant M. tuberculosis detection developed in this study offers a better alternative to conventional phenotypic isoniazid resistance determination, which will be of both clinical and epidemiological significance in resource-limited nations.

Food animal production is important for every country. Several antibiotic agents are used in poultry farming to reduce the economic losses arising from mostly untested infectious diseases. This continued study was performed to determine the prevalence of antibiotic-resistant Salmonella in broiler chickens, poultry farmers, and Salmonella bacteremia patients. A total of 121 Salmonella isolates were collected from the Thai provinces of Khon Kaen (65 isolates), Ratchaburi (43 isolates), and Phayao (13 isolates). Salmonella from chicken showed a high rate of resistance to nalidixic acid and tetracycline. Sixty-four percent of Salmonella isolates carried class 1 integrons (intI1 gene-positive). Among the 121 Salmonella isolates, there were 15 serotypes, with S. Enteritidis being the most common. A clonal relationship between the chicken and human isolates was demonstrated by 3 molecular typing methods: enterobacterial repetitive intergenic consensus polymerase chain reaction; pulsed-field gel electrophoresis; and high-throughput multilocus sequence typing. A spread of the sequence type 11 clone was found between chickens and humans. This study revealed a large-scale Salmonella outbreak in Thailand, a link between resistant bacteria from poultry farms and vertical transmission through the food chain, and horizontal transmission of resistance genes. These results can be used for future surveillance and monitoring.

Fabry disease (FD), like COVID-19, can affect multiple organs, including the lungs. Patients with FD are expected to develop severe COVID-19, due to involvement of not only the lungs but also the kidneys and the presence of other comorbidities. We present 2 cases of mild COVID-19 in patients with FD who were infected with the COVID-19 virus. Although it is unknown whether the X chromosome mutation in patients with FD affects the development of severe COVID-19, it is suggested that it may play a protective role against COVID-19 infection. Based on these cases, we suggest that FD is not a risk factor for severe COVID-19.

We previously reported the emergence and high prevalence of group B streptococci (GBS) with reduced penicillin susceptibility (PRGBS) clinical isolates in Japan. PRGBS tend to be non-susceptible to macrolides and fluoroquinolones. In our previous study, we found that the minimum inhibitory concentration (MIC) of daptomycin for one clinical isolate of GBS was above the susceptible breakpoint settled by the Clinical and Laboratory Standards Institute (CLSI). This suggests the possibility of the unrecognized spread of daptomycin-non-susceptible clinical GBS isolates in Japan. This study aimed to analyze the daptomycin susceptibility in 1,046 clinical GBS isolates that were recovered after the approval of daptomycin in Japan. MICs of daptomycin for the 1,046 clinical isolates were determined by the microdilution method recommended by the CLSI. The MIC range was 0.12–1 µg/mL, and the MIC₅₀ and MIC₉₀ were 0.5 µg/mL and 1 µg/mL, respectively. All the GBS isolates evaluated in this study were susceptible to daptomycin. Therefore, at present, daptomycin might be considered as a new option to treat GBS infections, especially multidrug-resistant PRGBS infections.

The 2019 novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused a global outbreak of infection. In general, children with coronavirus disease-2019 have been reported to show milder respiratory symptoms than adult patients. Here, we have described a case of a SARS-CoV-2-infected infant who presented to our hospital with a severe episode of an apparent life-threatening event (ALTE). An 8-month-old, otherwise healthy female infant presented to our hospital because of a sudden cardiopulmonary arrest. Approximately 1 h before this episode, the patient showed no symptoms, except a worse humor than usual. On arrival at our hospital, the patient had severe acidosis, but there were no clear signs of inflammatory response. Chest computed tomography showed weak consolidations in the upper right lung and atelectasis in the lower left lung. No signs of congenital heart disease or cardiomyopathy were observed on echocardiography, and no significant arrhythmia was observed during the clinical course. However, SARS-CoV-2 RNA was detected by real-time reverse transcription polymerase chain reaction in tracheal aspirate and urine samples. Although the assessment of further similar cases is indispensable, this case suggests that SARS-CoV-2 infection may be an underlying factor in the pathophysiology of ALTE.

The prevalence of quinolone- and macrolide-resistant Group B Streptococcus (GBS) is increasing worldwide, but the relationship between the resistance of GBS to these antibiotics and patient outcome remains unclear. Therefore, we evaluated whether blood stream infection caused by quinolone- or macrolide-resistant GBS is associated with high mortality. Our findings in 77 patients with GBS bacteremia demonstrate that quinolone and macrolide resistance may not be risk factors for 30-day mortality.

Through our previous work, we have identified that novel oxazolidinone structures, the biaryloxazolidinone analogues containing a hydrazone moiety, act as promising antibacterial agents against gram-positive bacterial strains. Based on this active structure, in this study, we synthesized a series of novel oxazolidinones and determined their anti-mycobacterial activities in vitro and in Mycobacterium marinum-infected zebrafish. The in vitro anti-mycobacterial assay demonstrated that all of the synthesized compounds have potent efficacy against both H37Rv and clinical mycobacterial isolates. Among all the generated active agents, (S)-N-(3-(2-fluoro-4'-(2-amino-4-thiazolyl)biphenyl-4-yl)-2-oxo-1,3-oxazolidie-5-ylmethyl)acetamide (compound 7), whose in vitro MIC was 10-fold lower than that of linezolid, showed the strongest bactericidal effects, with ~2.2-log reduction of M. marinum load in zebrafish at 10 mg/kg dosage. Other novel oxazolidinones, compounds 9, 12, 16, and 21, exhibited reduction range of 1.1–1.8 log against M. marinum and displayed better efficacy than linezolid. Our results indicate that these identified compounds have the potential to be further developed as novel anti-mycobacterial agents.

Coronavirus disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). First identified in December 2019, in Wuhan, China, it has since become a global pandemic. Complications of COVID-19 are not limited to the pulmonary system, but also include neurologic manifestations such as stroke. We report two cases of coincidental presentation of COVID-19 and cerebrovascular accident. Further studies are needed for a comprehensive understanding of the neurological pathology of COVID-19 and its effects on the nervous system, but stroke teams should be wary of the fact that COVID-19 patients may present with cerebrovascular accidents.