Japanese journal of infectious diseases最新文献

An ongoing pertussis epidemic in Okinawa has resulted in 227 reported cases since November 2024. Between December 2024 and February 2025, clinical specimens were collected from 31 cases. We isolated 18 macrolide-resistant Bordetella pertussis (MRBP) strains, all harboring the A2047G mutation in the 23S rRNA gene, confirmed by real-time PCR. Genomic analysis was performed on two MRBP isolated in November 2024 and the 18 MRBP from the current survey. All MRBP in Okinawa formed genetically related clusters with the ptxP3 allele in China (P745) and France (FR7302). However, MRBP strains from Okinawa were divided into three clusters, each with at least eight SNPs between them, and distinct from P745 and FR7302, suggesting the multi-source dissemination of ptxP3 MRBP in Okinawa.

This study investigated the diagnostic accuracy of the quantitative polymerase chain reaction (qPCR) DNA assay in urine and saliva samples, as well as its concordance with serum CMV IgM/IgG testing in infants suspected of congenital cytomegalovirus (cCMV) infection. Furthermore, the study sought to elucidate the correlation between various diagnostic parameters in suspected cases of congenital CMV. A cross-sectional analysis was conducted on newborns suspected of having cCMV infection at RSSA Malang. CMV serology, complete blood count, and qPCR of urine and saliva samples were collected. Statistical analysis was performed on these data with a p-value < 0.05. A significant difference in urine PCR CT value distinguished positive from negative CMV IgM serology groups. A strong correlation (r = 0.728, p < 0.001) and high agreement (κ = 0.693, p < 0.001) between urine and saliva PCR testing suggested saliva as a reliable and non-invasive alternative for newborn screening. The findings of this study underscore the necessity of a comprehensive screening protocol for cCMV, particularly considering the high seroprevalence of CMV in the Indonesian population.

The potency of diphtheria toxoid is determined by titrating neutralizing antibody levels in immunized mice using the Vero cell assay. The WHO manual recommends titration by determining the cytotoxic endpoint through measuring cell metabolism and observing cell morphology under a microscope, which has been conducted in our laboratory; however, the former is time-consuming and the latter subjective. To address these limitations, we have developed a novel endpoint determination method based on cell image analysis. We assessed the feasibility of this image analysis and compared it with microscopic observation and cell metabolism measurement. Consequently, image analysis proved effective for endpoint determination, yielding potency values comparable to existing methods in measuring potencies of commercial vaccines. These findings suggest that image analysis, being objective and convenient, can serve as a reliable alternative method for potency testing of diphtheria vaccines.

Staphylococcus argenteus, a novel species formally named in 2015 and distinct from S. aureus, has a historical distribution that remains unclear. In this study, a total of 1,021 staphylococcal isolates collected from food-related specimens in Nagoya City between 1986 and 2022 were re-examined. Of these, 65 isolates (6.4%) were reidentified as S. argenteus. The earliest detection was in 1986, and the species has been identified in nearly every subsequent year. These findings suggest that S. argenteus had already disseminated into food-related environments by the 1980s. Furthermore, the results indicate that most S. argenteus isolates have been correctly identified in recent years, due to improvements in current MALDI-TOF MS identification. Multilocus sequence typing (MLST) revealed ST2854 as the most prevalent sequence type (ST) in this study, while clinically important strains such as ST1223 and ST2250 have been detected since the 1990s. The presence of novel and multiple STs with distinct POT types indicating that genetically diverse S. argenteus strains have been present in food-related environments since the 1980s. These results provide important insight into the historical background of S. argenteus and underscore the need for continued monitoring, particularly in food-related environments.

Hepatitis A virus (HAV) and hepatitis E virus (HEV) are believed to have similar routes of transmission and epidemiology in developing countries. This study investigated the seroprevalence of these pathogens among healthy individuals from the Dhanusha district of Madhesh Province, Nepal. Ninety serum samples collected between 2022 and 2023 were analyzed using enzyme-linked immunosorbent assay to detect immunoglobulin (Ig) G antibodies against HAV and HEV. Participants (median age, 23 years; range, 1-45 years) were categorized into five age groups: 1-10, 11-20, 21-30, 31-40, and 41-45 years. The prevalence of HAV and HEV IgG was 96.7% and 13.3%, respectively. All age groups showed high positivity rates for HAV antibodies. In contrast, HEV infection rates were extremely low in children but rapidly increased in adults aged >31 years. No significant correlation was observed between HAV and HEV seropositivity rates. Additional studies, including those in other areas of Nepal, are required for the nationwide serosurveillance of HAV and HEV.

Ticks are the vectors of tick-borne diseases (TBDs) in humans and wild vertebrates. The relationship between ticks, host vertebrates, and their pathogens should be investigated for effective control of TBDs. This study aimed to detect vertebrate DNA in ticks using molecular methods and identify the species of ticks collected in Fukuoka Prefecture, which is located in the northern Kyushu area of Japan. Ticks from vegetation were collected from the vegetation by flagging between 2017 and 2023. Of the 152 ticks collected by flagging, 65 (42.8%) harbored vertebrate DNA. By stage, vertebrate DNAs were detected in 26 of 83 nymphs (31.3%) and 39 of 69 adults (56.5%). Among the host vertebrates, Sika deer was the main blood-feeding source for ticks in Fukuoka Prefecture. Owing to the widespread of deer across this prefecture, controlling its population and other wildlife populations could be a countermeasure to reduce the TBD risk.

In 2023, an external quality assessment (EQA) of nucleic acid amplification tests for SARS-CoV-2 was conducted among clinics that implemented testing instruments through the Tokyo Subsidy Program for Facilities and Equipment for Testing in COVID-19. The survey samples consisted of sample 1 (20,000 copies/mL), sample 2 (10,000 copies/mL), and a negative sample. Results were obtained through cycle threshold (Ct) values and positive-negative result determinations. On-site technical support was provided to clinics that responded incorrectly. A total of 544 clinics (589 instruments) participated, and Abbott's ID NOW ^TM (82.2%) was the most widely used instrument. The qualitative test results showed high accuracy rates of 95.2% for Sample 1, 93.2% for Sample 2, and 96.3% for negative samples. Differences in Ct values were observed between reagents and instruments. Technical support was provided to 63 clinics. The discrepancies in the qualitative tests were mainly due to deviations from the protocol instructions, mixing of all three survey samples into one vial, and errors caused by foaming. This survey was unique in that the participants were mostly end users who were not laboratory testing specialists and mainly used point-of-care testing instruments. It is important to continue EQA to improve and maintain testing accuracy.

Recombinant human adenoviruses (HAdVs) have been identified in many countries, including Japan. Herein, we report a recombinant HAdV-C type detected in feces with gastroenteritis infection or throat swabs with upper respiratory tract inflammation in six children in Aichi Prefecture. This type may have been prevalent in the area. Between April 2014 and March 2019, we attempted to detect HAdVs in 9,483 specimens (feces, urine, and throat and conjunctival swabs) collected from patients with suspected viral infection. A total of 220 HAdV-C isolates were obtained and serotyped using a neutralization test (NT). Of these, 62 HAdV-C strains (HAdV-C1: 15, -C2: 19, -C5: 22, and -C6: 6) were genotyped by sequencing for the three regions, penton base, hexon, and fiber regions, respectively. All 62 strains were grouped into the same genotype as the serotype for the hexon and fiber regions. In contrast, phylogenetic analysis showed that 6 of the 22 strains with serotype HAdV-C5 were grouped into HAdV-C89 for the penton base region. This type was detected as a recombinant HAdV causing severe acute respiratory infection in China between 2017 and 2021 and has been persistently detected in the transnational Aichi Prefecture over the same period.

Guidelines for sexually transmitted infections recommend oral metronidazole (MNZ) as the first-line treatment option for vaginal trichomoniasis; however, cases of prolonged symptoms or post-treatment recurrence have been reported. This retrospective cohort study aimed to determine appropriate treatment strategies for refractory vaginal trichomoniasis. 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 initial MNZ treatment failure. 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 sexually transmitted diseases. However, TNZ was effective, which suggests that MNZ-resistant T. vaginalis may have been the cause. MNZ resistance testing was not performed in this study; however, treatment with TNZ should be considered in cases of refractory vaginal trichomoniasis, possibly resulting from MNZ-resistant T. vaginalis.

Ensitrelvir is a novel antiviral drug that has been evaluated for its effectiveness against Coronavirus disease 2019 (COVID-19). This study aims to gather relevant evidence regarding the efficacy and safety of ensitrelvir in patients diagnosed with COVID-19. A systematic search was conducted in databases including PubMed, the Cochrane Library, Web of Science, and Scopus to identify pertinent studies on ensitrelvir's role in COVID-19 treatment up to September 2024. Nine studies were included in the analysis, comprising two retrospective studies, two phase 1 trials, three phase 2/3 trials, and two phase 3 trials. The findings indicated that ensitrelvir is associated with a reduced risk of death and shorter hospital stays for COVID-19 patients compared to control groups. Additionally, ensitrelvir demonstrated the ability to lower SARS-CoV-2 viral titers and RNA levels while accelerating the time to viral clearance compared to placebo. Reported adverse events were predominantly mild, with no serious adverse events noted. Ensitrelvir exhibited consistent pharmacokinetics across different populations, eliminating the need for dose adjustments. Ensitrelvir appears to be an effective and safe option for managing mild to moderate COVID-19 infections. However, further studies are needed to establish its efficacy and safety in treating COVID-19.