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The circulation of arboviruses in livestock ruminants has often gone unrecognized owing to the fact that a significant percentage of arboviruses probably induce subclinical infections and/or negligible symptoms in infected animals. To determine the current situation of arbovirus circulation in the Yaeyama Islands, attempts to isolate viruses from bovine blood samples collected between 2014 and 2019 have been made. In total, 308 blood samples were collected during the study period, and 43 of them induced cytopathic effects (CPEs) in cell cultures. The identification of the CPE agents was performed by reported RT-PCR assays and a high-throughput analysis with a next-generation sequencing platform. The obtained viruses consisted of an orthobunyavirus (Peaton virus), Culicoides -borne orbiviruses (bluetongue virus serotypes 12 and 16, epizootic hemorrhagic disease virus [EHDV] serotypes 5, 6, and 7, D'Aguilar virus, and Bunyip Creek virus), and potential mosquito-borne orbiviruses (Yunnan orbivirus, Guangxi orbivirus, and Yonaguni orbivirus). Most of the orbiviruses were recovered from washed blood cells with mosquito cell cultures, suggesting that this combination was more efficient than other combinations such as plasma/blood cells and hamster cell lines. This marked the first time that the isolation of EHDV serotypes 5 and 6 and three potential mosquito-borne orbiviruses was recorded in Japan, showing a greater variety of orbiviruses on the islands than previously known. Genetic analysis of the isolated orbiviruses suggested that the Yaeyama Islands and its neighboring regions were epidemiologically related. Some of the viruses, especially the potential mosquito-borne orbiviruses, were isolated during several consecutive years, indicating their establishment on the islands.

Background: In a pilot study, we showed that topical administration of a tetracycline could decrease oral bacteria levels for 6 hours in patients who underwent oral cancer surgery combined with tracheotomy and flap reconstruction. This multicenter, randomized control trial aimed to investigate the effectiveness of topical application of tetracycline ointment for prevention of surgical site infection (SSI) associated with major oral cancer surgery., Methods: One hundred seventeen patients who underwent oral cancer resection combined with neck dissection, flap reconstruction, and tracheotomy were divided randomly into an intervention group (n = 56) and a control group (n = 61). The intervention consisted of topical administration of tetracycline ointment on the dorsum of the tongue every 6 hours for 48 hours postoperatively. Factors relating to the occurrence of SSI in both groups were subjected to logistic regression analysis., Results: SSI occurred in 11 patients (19.6%) in the intervention group and 22 patients (36.1%) in the control group. Multivariate analysis showed that a longer operating time and not receiving topical tetracycline were independent risk factors for development of SSI., Conclusion: Administration of topical tetracycline for 48 hours postoperatively is an effective way of preventing SSI after oral cancer surgery.