Background: It is challenging to diagnose infected aneurysm in the early phase. This study aimed to describe the clinical and microbiological characteristics of infected aneurysm, and to elucidate the difficulties in diagnosing the disease. Methods: Forty-one cases of infected aneurysm were diagnosed in Nagasaki University Hospital from 2005 to 2019. Information on clinical and microbiological characteristics, radiological findings, duration of onset, and type of initial computed tomography (CT) imaging conditions were collected. Factors related to diagnostic delay were analyzed by Fisher’s exact test for categorical variables or by the Wilcoxon rank-sum test for continuous variables. Results: Pathogens were identified in 34 of 41 cases; the pathogens were Gram-positive cocci in 16 cases, Gram-negative rods in 13 cases, and others in five cases. Clinical characteristics did not differ in accordance with the identified bacteria. At the time of admission, 16 patients were given different initial diagnoses, of which acute pyelonephritis (n = 5) was the most frequent. Compared with the 22 patients with an accurate initial diagnosis, the 19 initially misdiagnosed patients were more likely to have been examined by plain CT. The sensitivities of plain CT and contrast-enhanced CT were 38.1% and 80.0%, respectively. Conclusions: In cases of infected aneurysm, diagnostic delay is attributed to non-specific symptoms and the low sensitivity of plain CT. Clinical characteristics of infected aneurysm mimic various diseases. Contrast-enhanced CT should be considered if infected aneurysm is suspected.

Japanese spotted fever (JSF) is a tick-borne rickettsial disease prevalent in western Japan, with an increasing incidence and geographical distribution. This retrospective study aimed to describe the clinical features of JSF and identify factors associated with its severe form. We included adult patients with laboratory confirmed JSF in Nagasaki prefecture from 2010 to 2021. Severe JSF was defined by the presence of altered mental status, low blood pressure, or low oxygen saturation. In total, 65 JSF cases were diagnosed. Common symptoms were fever (87%), rash (48%), and fatigue (48%) with eschars detected in 50 (79.4%) of patients. Thirty-eight (60.3%) patients were initially diagnosed with non-JSF conditions. Twenty-one (33.3%) cases were categorized as severe JSF, including one death. Pre-hospital factors associated with severe JSF included age ≥75 (adjusted odds ratio [aOR] 37.53, 95% confidence interval [CI] 3.03-465.38), male sex (aOR 26.5, 95% CI 4.23-166.00), and a treatment delay ≥4 days from onset (aOR 5.96, 95% CI 1.13-31.60). This study highlights diagnostic challenges of JSF due to its non-organ-specific clinical presentation. Delayed initial treatment, advanced age, and male sex significantly increase the risk of severity. It is crucial to further raise awareness of JSF among clinicians and residents in endemic areas.

Background: 5-aminolevulinic acid (5-ALA), a natural amino acid that is marketed alongside sodium ferrous citrate (SFC) as a functional food, blocks severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) proliferation in vitro and exerts anti-inflammatory effects. In this phase II open-label, prospective, parallel-group, randomized trial, we aimed to evaluate the safety and efficacy of 5-ALA in patients with mild-to-moderate coronavirus disease 2019. Methods: This trial was conducted in patients receiving 5-ALA/SFC (250/145 mg) orally thrice daily for 7 days, followed by 5-ALA/SFC (150/87 mg) orally thrice daily for 7 days. The primary endpoints were changes in SARS-CoV-2 viral load, clinical symptom scores, and 5-ALA/SFC safety (adverse events [AE] and changes in laboratory values and vital signs). Results: A total of 50 patients were enrolled from 8 institutions in Japan. The change in SARS-CoV-2 viral load from baseline was not significantly different between the 5-ALA/SFC (n = 24) and control (n = 26) groups. The duration to improvement was shorter in the 5-ALA/SFC group than in the control group, although the difference was not significant. The 5-ALA/SFC group exhibited faster improvement rates in “taste abnormality,” “cough,” “lethargy,” and “no appetite” than the control group. Eight AEs were observed in the 5-ALA/SFC group, with 22.7% of patients experiencing gastrointestinal symptoms (decreased appetite, constipation, and vomiting). AEs occurred with 750/435 mg/day in 25.0% of patients in the first phase and with 450/261 mg/day of 5-ALA/SFC in 6.3% of patients in the second phase. Conclusion: 5-ALA/SFC improved some symptoms but did not influence the SARS-CoV-2 viral load or clinical symptom scores over 14 days. The safety of 5-ALA/SFC in this study was acceptable. Further evaluation using a larger sample size or modified method is warranted.

A 77-year-old man with urinary tuberculosis developed post renal anuria two days after starting an anti-tuberculosis drug regimen. He had bilateral hydronephrosis, and his right kidney was radiologically diagnosed to be non-functioning. A transurethral catheter was placed in the left ureter. No improvement in the ureteral stricture was noted during the initial three weeks of treatment; however, the stricture did thereafter improve after the commencement of oral prednisolone. In cases of urinary tuberculosis, ureteral stricture can deteriorate and result in ureteral obstruction during anti-tuberculosis treatment. Pre-emptive administration of corticosteroids may be beneficial for preventing such stricture in patients with a pre-existing ureteral lesion.

Tick-borne viral infections, including severe fever with thrombocytopenia syndrome virus (SFTSV), are increasingly recognized as a significant threat to global public health owing to their rapid dissemination and high mortality rates. While isolated outbreaks within single species have been documented, reports of multi-host cluster cases remain scarce. This study describes a consecutive, cross-species outbreak of severe fever with thrombocytopenia syndrome disease between April and May 2024 on a remote island in Nagasaki Prefecture that involved four cats and four humans. An interdisciplinary investigation integrating molecular phylogenetic analysis of viral genomes—including previously identified Nagasaki strains of SFTSV—and haplotype network analysis provided insights into the infection dynamics. Despite the absence of confirmed direct contact between cats and humans, four animals and one patient succumbed to the infection. Genomic analyses demonstrated high similarity to circulating Nagasaki strains, whereas haplotype analysis indicated multiple viral introduction events and complex transmission pathways, reflecting diverse sources. These findings underscore the critical need for a One Health approach—integrating human, animal, and vector surveillance—to effectively monitor, understand, and control tick-borne viruses globally, in both endemic and emerging regions.

Severe fever with thrombocytopenia syndrome (SFTS), primarily endemic to East Asia, is a high-fatality tick-borne disease caused by Dabie bandavirus, commonly called SFTS virus (SFTSV). Although several cases in companion animals have been reported across the endemic regions, no studies have examined SFTSV infection rates among questing ticks collected from the vicinity of SFTS-positive companion animals shortly after case occurrence. We conducted three field surveys (A, B, and C) of ticks within 14-22 days after the onset of SFTS in companion animals in Nagasaki Prefecture, Japan. A diverse range of tick species were collected: Haemaphysalis kitaokai adults were dominant in survey A (83%) and Haemaphysalis formosensis nymphs in surveys B (74%) and C (38%). Genetically-detected SFTSV positivity rates among pooled samples were 0%, 12%, and 21% in surveys A, B, and C. Notably, an exceptionally high positivity rate (4/5 pools, 80%) at a single sampling point in survey C indicated a highly heterogeneous spatial distribution, suggesting localized SFTSV small-scale foci (microfoci). In a follow-up survey conducted at the spots with positive ticks in survey C 3 months later, the tick population had markedly shifted (the predominant species was larval Haemaphysalis hystricis), and no SFTSV-positive ticks were detected. These findings suggest substantial variability in SFTSV positivity in ticks, even around confirmed SFTS cases, indicating the presence of transient microfoci after an SFTS case. Further investigation is needed to clarify the ecological and environmental factors governing the emergence and persistence of these microfoci and their implications for local risk assessment.