Multilocus microsatellite typing (MLMT) was performed on 93 strains of Microsporum canis (M. canis) isolated between 2012 and 2017 from 75 cats, 8 dogs, and 10 pet owners. These strains were derived from 2 major reservoirs: commercial breeding facilities and pet shops (PS), and stray cats and pet cats that went outdoors and came in contact with stray cats (Outdoor). Six microsatellite markers were used for genotyping. These 93 strains included 22 genotypes; 11 had been previously detected in Japan while the other 11 were new. Strains belonging to the previously reported genotypes, P and A, were distributed widely throughout Japan. Genotype P was the most frequent, accounting for 37 (39.8%) of the 93 strains. Most were derived from Outdoor sources. Genotype A was the second most frequent (11 of 93 strains, 11.8%). Most of the genotype A strains were derived from the PS reservoir. All new genotypes were detected in isolates from cats. Many of these were derived from the Outdoor reservoir. Consistency of infection was observed in 18 of the 19 familial cases. These findings indicate that genotypes differ in strains derived from PS and Outdoor reservoirs. MLMT genotyping is useful for tracking the routes of spread and transmission of M. canis in Japan.

Japan recently approved a quadrivalent human papillomavirus (HPV) vaccine for males, but the 9-valent vaccine has only been approved for females. Given the low female vaccination rate due to concerns about adverse events in Japan, quantifying the risks and benefits of the HPV vaccination for males may help in deciding whether to vaccinate adolescent boys in Japan. Using quality-adjusted life years, the risk–benefit ratio for an adolescent boy receiving the 9-valent HPV vaccination was calculated. The male HPV vaccination reduced the QALYs gained due to head and neck cancer, anal cancer, penile cancer, genital warts, and recurrent respiratory papillomatosis by 401.63, 20.38, 9.40, 28.79, and 69.13 per 100,000 vaccinated persons, respectively. The total risk of vaccination was 11.85. The risk–benefit ratio for a 12-year-old boy who received the HPV vaccination series was found to be 0.022 (benefit–risk ratio, 44.670). In the sensitivity analysis, the risk–benefit ratio ranged from 0.0001 to 0.11 for all scenarios. Hence, much larger benefits than risks linked with the male HPV vaccination were observed from an individual perspective. The results support the inclusion of sex-neutral HPV vaccinations into the national immunization program as well as strengthens the decision for adolescent boys to receive the vaccination.

Human coronaviruses (HCoVs) are distributed globally and they cause a range of respiratory symptoms. Since HCoV infection usually causes mild upper respiratory tract disease and currently has no specific therapy, there are limited reports on its features, especially in adults. We aimed to evaluate the features of HCoV infections in clinical settings. Adult patients with respiratory symptoms from October 2014 to September 2019 at Nagasaki Genbaku Isahaya Hospital were enrolled. Multiplex reverse transcription-polymerase chain reaction as performed for 15 viruses, including HCoVs, and eight bacterial species on the patients’ respiratory specimens. A total of 121 cases were recruited with HKU1, OC43, 229E, and NL63 strains in 80, 21, 12, and 11 cases, respectively. The percentage of HCoV-infected patients peaked in winter (47.5%). Symptoms of fever (69.4%), cough (47.9%), and comorbidities of asthma/cough variant asthma (34.7%) were frequently observed. Lymphocytopenia and increased C-reactive protein levels were observed in laboratory tests. Co-infection with other viruses was identified in 38.8% of the cases. In the repeat-positive cases, 42% were repeat positive within 100 days. HCoV-infected patients showed winter seasonality with a high frequency of comorbidity with asthma and co-infections. Re-infection within an early period was suspected, but further consideration is required.

Childhood brucellosis presents various nonspecific clinical symptoms, and limited laboratory data exist for clinical diagnosis. A better understanding of these clinical and laboratory characteristics can avoid clinical misdiagnosis and mistreatment. In this case-series study, a total of 78 children with a confirmed diagnosis of brucellosis were evaluated retrospectively. We observed that the incidence rate was high in the first two quarters every year. The most common symptom was fever. Osteoarticular involvement was found in 44.87% of the patients. Laboratory tests showed that the values of erythrocyte sedimentation rate, C-reactive protein (CRP), hemoglobin, neutrophils (NEU), alanine aminotransferase (ALT), and ferritin in childhood brucellosis with osteoarticular involvement had significant differences than those without osteoarticular involvement or control group (P < 0.05). Childhood brucellosis without osteoarticular involvement is often accompanied by decreased NEU and increased CRP and ALT compared with that of the control group (P < 0.05). The Receiver Operating Curves analysis revealed that NEU, CRP, and ALT could be used as adjunct parameters in the differential diagnosis of childhood brucellosis. These data suggest that clinical and laboratory characteristics are essential for every clinician and may have a complementary role in diagnosing childhood brucellosis.

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging hemorrhagic fever, and the causative pathogen, the SFTS virus (SFTSV), was first discovered in China in 2010. In this study, a retrospective analysis of 86 patients that were diagnosed with SFTS from two 5-year periods (2011–2015 and 2016–2020) was performed to explore the changes in epidemiology, clinical characteristics, laboratory parameters, and prognosis between both periods. The results showed that there were significant differences in age, the proportion of farmers, geographical distribution, the incidence of multiple organ dysfunction, the decrease in thrombocyte count, and the elevations of serum AST and lipase levels between the two groups (P < 0.05). Additionally, the case-fatality rate in the 2016–2020 group (16.7%) was higher than that in the 2011–2015 group (6.25%), although the difference was not significant. Our study shows that SFTS is broadly distributed across Anhui Province and the mortality rate is high. May to July was the peak of the epidemic, and farmers constituted a high-risk group. In recent years, thrombocytopenia has become more serious, and multiple organ dysfunction is more common. Clinicians need to strengthen their knowledge of the changing epidemiological and clinical characteristics of this disease.

From August 27 to October 15, 2014, a dengue fever outbreak with 158 autochthonous cases occurred after nearly 70 years of no reports of autochthonous cases in Japan. The most competent mosquito vector for dengue virus (DENV) transmission in Japan is Aedes albopictus. Since A. albopictus is widely distributed throughout Japan, we examined the susceptibility of this species to infection by DENV and the relationship of the endosymbiont Wolbachia (wAlbA and wAlbB) with susceptibility to DENV. The A. albopictus YYG strain, collected from the Yoyogi Park in 2014, the epicenter of the dengue fever outbreak, was found to have lower susceptibility to DENV 1 and 3 than that of the indigenous Japanese strains A. albopictus EBN 201808 (F1 from the field) and A. albopictus ISG 201603. Furthermore, the A. albopictus EBN 201808 strain showed the same susceptibility to DENV3 as the A. albopictus ISG 201603tet strain (Wolbachia-free). Susceptibility to DENV3 was not related to Wolbachia strains wAlbA or wAlbB in the A. albopictus ISG 201603 strain.

With the spread of coronavirus disease, reports have indicated that young patients are usually asymptomatic with a short convalescence period. The current study compared the time to resolution of infection in symptomatic and asymptomatic patients. Seventy-six patients aged 44.4 ± 23.3 years were admitted to the coronavirus disease 2019 (COVID-19) unit during the study period. Data were collected from patient records. Throat and nasal swabs for COVID-19 were collected for reverse transcriptase-polymerase chain reaction (RT-PCR). Time to resolution of infection was defined as the number of days from the date of the first COVID-19 positive outcome to the second consecutive negative PCR results. Most patients showed COVID-19 signs and symptoms (71.1%) between 1 and 6 days, and the rest were asymptomatic. No association was found between the time to resolution of infection and the presence of COVID-19 signs and symptoms (symptomatic: median [Md] 10.0, 95% confidence interval [CI] 8.4–11.6; asymptomatic: Md 15.0, 95% CI 10.5–15.5; P = 0.54). Age was not correlated with the number of COVID-19 signs and symptoms (r = 0.13, P = 0.37) or with the time to resolution of infection (r = 0.06, P = 0.58). In patients with mild to moderate symptoms, the time to resolution of infection from COVID-19 is not different from that in asymptomatic patients.

Citrobacter koseri (C. koseri) is an opportunistic pathogen that can cause a variety of diseases. Although the mortality rate of C. koseri infections is high, there is a paucity of clinical information. Furthermore, the genomic features of this species are poorly understood. Herein, we present a patient with endogenous endophthalmitis secondary to septicemia, and collected a C. koseri isolate, CKNJ, from the blood of the patient. Whole genome sequencing revealed that CKNJ harbors no plasmids and codes for 67 putative virulence factors. Whole genome single nucleotide polymorphism-based phylogenetic analysis revealed that the CKNJ strain was close to strains with the same isolation sites. Compared to the other sequenced C. koseri chromosomes, CKNJ contains several strain-variable regions, including one prophage and 2 large genomic islands. Sequencing of the first complete genome of a clinical strain from China should reinforce our understanding of the genomic features and pathogenicity of this invasive infection-causing C. koseri with clinical significance.

Escherichia albertii is an emerging zoonotic foodborne pathogen. Several outbreaks of E. albertii have occurred, particularly in Japan. Although birds have been considered as one of the most important reservoirs of this bacterium, information regarding its prevalence in birds is still scarce. We performed a survey of E. albertii in wild birds in Japan and examined the characteristics of these isolates. E. albertii-specific genes were detected in five cloacal swabs from 156 birds by PCR. Four E. albertii strains were isolated from a swallow with two different E. albertii strains and two pigeons in a flock using XRM-MacConkey agar. These isolates were assigned to biogroup 3, showed no resistance to any tested antimicrobials, and were classified into two EAO-genotypes (EAOg2 and EAOg33) and were untypable. Similar to clinical E. albertii strains, these isolates carried virulence genes, including eae (n = 4), paa (n = 4), Eccdt-I (n = 2), and stx2f (n = 1), as well as Eacdt. Furthermore, stx2f genes in a strain were located on an inducible bacteriophage, which can confer the ability to produce Stx2f in E. coli. In conclusion, Japanese wild birds carried E. albertii at levels similar to the reported prevalence in birds. These isolates may have the potential to cause gastroenteritis in humans.

Viruses are the most common cause of lower respiratory tract infections (LRTIs) in children. Our study aimed to shed light on co-infection by comparing it with the most common single agents, such as respiratory syncytial virus (RSV) and rhinovirus (RV), in terms of epidemiological, clinical, laboratory findings, and cost. This retrospective study analyzed medical records pertaining to infants aged below 5 years, hospitalized with a diagnosis of LRTI with RSV, RV, or co-infection. The study group consisted of 199 children, RSV was detected in 116 patients (58.3%), RV in 46 (23.1%), and co-infections in 37 (18.6%). The average age of patients infected with RV was higher (P = 0.006), and the length of hospital stay of patients infected with RSV was longer (P = 0.03) than that with other agents. There was no significant difference between the groups in terms of oxygen requirement, intensive care unit admission, intubation, and development of complications. The cost was significantly higher in the RSV group (P = 0.02) compared to the other groups. Viral co-infections, RSV, and RV constitute an important part of the etiology in patients aged below 5 years; co-infections do not cause more severe clinical findings compared to single viral agents.

Serodiscordant couples serve as potential sources of human immunodeficiency virus (HIV) transmission. Understanding the demographic dynamics of serodiscordant couples plays an important role in tailoring interventions to eliminate HIV infection. We conducted this cross-sectional analysis among 314 integrated counseling and testing centers in West Bengal, India, from April 2016 to March 2020. General individuals who were detected as HIV-reactive and whose spouses were also tested for HIV comprised the study population, in which a total of 8,740 couples were included. Sociodemographic variables were compared across concordant and discordant arms, as well as between male positive (M+ F−) and female positive (F+ M−) subgroups of serodiscordant couples. Among the couples studied, 35.2% (95% CI: 34.2–36.2%) were serodiscordant. Among serodiscordant couples, the proportion of M+ F− (86.1%) was significantly higher than that of F+ M− (13.9%). We observed that higher mean ages of couples, higher education, business and service occupations, and urban residence were significantly associated with the serodiscordance relationship (P < 0.05). A high mean age of couples and a low proportion of housewives were associated with the F+ M− subgroup. As approximately 35% of serodiscordant couples carry the risk of transmission to negative spouses, particularly in older age and urban residence, reorientation of HIV programs may be required to avert transmission in the future.

The national action plan on antimicrobial resistance (AMR) in Japan emphasizes the importance of understanding antimicrobial use (AMU). Some studies have been conducted on oral and parenteral AMU in Japan. However, there are few studies on the use of topical antimicrobials, such as in dermatology and ophthalmology. Therefore, the purpose of this study was to investigate the use of topical AMU in Japan. Data on AMU in dermatology and ophthalmology were obtained from the 2017 National Database of Health Insurance Claims and Specific Health Checkups of Japan Open Data. The number of dermatological products used was 58,396,530 in 2017. The proportions of betamethasone/gentamicin and gentamicin used were 50.5% and 16.7%, respectively, whereas that of the ingredient quantity in gentamicin was 7.8%. It has been suggested that topical AMU should be evaluated based on the number of products being used. The number of ophthalmological products used was 24,655,653 in 2017, and the proportion of quinolones used was 95.9%. The high prescription rate of quinolones may cause an increase in quinolone resistance in the ophthalmologic field. Topical AMU, which is a potential “blind spot” in the measures against AMR, needs to be continuously monitored, together with systemic AMU.

Xpert Xpress Flu/RSV is a fast and automated real-time nucleic acid amplification tool for detecting influenza virus and respiratory syncytial virus (RSV). The aim of this study was to verify the accuracy of Xpert Xpress Flu/RSV for detecting influenza virus and RSV. PubMed, EMBASE, Cochrane Library, and Web of Science databases were searched up to October 2020. The quality of the original research was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 guidelines. Meta-DiSc 1.4 software was used to analyze the sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and summary receiver operating characteristic curve. Deek’s funnel plot asymmetry test was used to evaluate the publication bias using the Stata 12.0 software. Ten studies with 25 fourfold tables were included in the analysis. The sensitivity of Xpert Xpress Flu/RSV for detecting influenza A, influenza B, and RSV were 0.97, 0.98, and 0.96, respectively, and the specificities were 0.97, 1.00, and 1.00, respectively. Compared with other common clinical real-time reverse transcription-polymerase chain reaction (RT-PCR), Xpert Xpress Flu/RSV is a valuable tool for diagnosing influenza virus and RSV with high sensitivity and specificity.

An outbreak of coronavirus 2019 (COVID-19) occurred in Ueda City, Nagano prefecture, Japan, which has a population of 150,000. The residents were a population naïve to COVID-19, and many of them had only one chance of exposure, in which careful epidemiological investigation could reveal attack rates among close contact on the specific date of exposure. We identified 89 cases and 328 close contacts. Among the close contacts, 114 had only one chance of exposure to the 20 index cases. During the follow-up period, 17 close contacts tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), overall attack rate of 15%, after the exposure to 6 infectors. The median number of close contacts for the 6 infectors was 5.5 (range 2–14). Attack rates among these close contacts were 13% (1/8), 20% (2/5), 33% (2/6), 50% (1/2), 64% (4/9 and 5/5), and 100% (2/2), respectively. The transmission risk of SARS-CoV-2 appears to peak one day before symptom onset, and is at similar levels two days before (16%) and on the day (20%) of symptom onset. A multidisciplinary approach is needed to control the COVID-19 outbreak, in addition to investigation, which began after case identification.

Viruses belonging to the genus Quaranjavirus in the family Orthomyxoviridae are known as argasid tick-borne viruses. Some viruses in this genus or an unassigned quaranjavirus-like variant can infect humans, although little is known about their pathogenicity. During the surveillance of tick-borne viruses in ixodid ticks in Ehime Prefecture, Japan, novel quaranjavirus-like sequences were detected in 3 pooled samples of Haemaphysalis histricis nymphs. Phylogenetic analysis revealed that the detected viruses formed a cluster with quaranjaviruses and other related viruses. Specifically, the viruses were closely related to Zambezi tick virus 1 and Uumaja virus, which are quaranjavirus-like viruses recently discovered in ixodid ticks in Africa and Europe, respectively. These findings indicate that the viruses detected in this study were probably new members of the Quaranjavirus genus or a related group. The viruses were tentatively named “Ohshima virus” even though only limited sequences of their genomes were available. This is the first report on the detection of a quaranjavirus-like virus in the East Asian region. Further investigations are needed to discern its infectivity and pathogenicity against humans and other animals and to determine the potential risk of an emerging tick-borne viral disease.

Campylobacter jejuni is a major foodborne pathogen that causes enteritis in humans, and is also known to be an antecedent infectious factor for Guillain-Barré syndrome (GBS). The onset of GBS after C. jejuni infection results from molecular mimicry between human neuronal gangliosides and C. jejuni lipooligosaccharides (LOS). C. jejuni HS:19 has been previously isolated from GBS cases more frequently than other serotypes in Japan. Therefore, in this study, we performed molecular analysis of 88 HS:19 isolates from GBS cases, sporadic diarrhea patients, and poultry meat samples, using multi-locus sequence typing and LOS class analysis. As a result, 87 of the 88 HS:19 isolates were typed as ST22 / CC22 and LOS class A1, while one was typed as ST1947 / CC22 and LOS class A1. Furthermore, the analysis of another 331 isolates from sporadic enteritis cases showed that only 34 (10.3%) were classified as LOS class A, including HS:19 (25 isolates), HS:2 (8 isolates), and HS:4c (1 isolate). In conclusion, C. jejuni HS:19 had high clonality, regardless of its origin, compared to other capsule types in Japan.

Many studies have been conducted on ventilator-associated complications (VACs) in patients with coronavirus 2019 (COVID-19). However, in these studies, the causative organisms were similar, and there were no reports on VAC corresponding with Corynebacteria. Coryneforms are frequently cultured in cases of polymicrobial infections and are usually considered contaminants in respiratory specimens. However, Corynebacterium pseudodiphtheriticum or C. striatum is known to be a pathogen in lower respiratory tract infections. We report three cases of VAC, probably due to C. pseudodiphtheriticum, in patients with COVID-19. If purulent lower respiratory tract specimens showed coryneform predominantly upon Gram staining, empirical therapy should be started. Furthermore, species identification and drug susceptibility testing should be performed.

Transitioning from intravenous to oral antibiotic therapy for Escherichia coli bacteremia could reduce the length of hospital stay and drug costs without compromising efficacy. Despite the expansion of extended-spectrum β-lactamase (ESBL)-producing E. coli, limited data are available regarding the effectiveness of switching to oral antibiotic therapy in patients with bacteremia caused by this organism. To compare clinical outcomes between oral transition therapy and intravenous therapy in patients with bacteremia due to ESBL-producing E. coli with a urinary source, we conducted a retrospective cohort study at 3 Japanese hospitals. The effects were estimated by Cox hazard analysis using propensity scores. Among 996 patients with bacteremia due to E. coli, 73 were included in the study. In the adjusted analysis weighted by propensity scores including 26 patients in the oral switch group and 47 in the intravenous group, oral transition did not increase the risk of treatment failure within 60 days (adjusted hazard ratio 0.86, 95% confidence interval 0.18–4.10), whereas the length of hospital stay was shorter in the oral switch group than in the intravenous group (median, 12 days vs. 19 days, P = 0.04). Intravenous-to-oral transition may be an effective treatment option that shortens the hospital stay.

Nonpharmaceutical interventions (NPIs) for COVID-19 can affect the current and future dynamics of respiratory syncytial virus infections (RSV). In Tokyo, RSV activity declined by 97.9% (95% CI: 94.8%–99.2%) during NPIs. A long period of NPIs could increase susceptible populations, thus enhancing the potential for large RSV outbreaks after the end of NPIs.