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.

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.

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.

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.