Uirusu最新文献

Viral hemorrhagic fevers such as Ebola virus disease, Marburg disease, Lassa fever, and Crimean-Congo hemorrhagic fever are infectious diseases that can cause severe, life-threatening illness. At present, there are only few licensed vaccines and antiviral drugs for these viral hemorrhagic fevers. The viruses which cause these viral hemorrhagic fevers are classified as BSL-4 pathogens and can be handled only in BSL-4 containment laboratories. Therefore, to develop the vaccines and treatments for these diseases, BSL-4 facility is essential. However, the BSL-4 facility available for the basic or applied research using infectious BSL-4 pathogens has not been established in Japan so far. In July 2021, the construction of BSL-4 facility was completed at the campus of Nagasaki University. After the preparation for the full operation, the facility will be approved by the Minister of Health, Labour and Welfare as a BSL-4 facility. Here, I introduce the BSL-4 facility project of Nagasaki University and state the contributions of the BSL-4 facility to research and development.

In a current life sciences research, we are in an era in which advanced technology emerging and utilize big data. Data-driven approaches such as machine learnings play an important role to analyze these datasets. However, limited clinical (time-course) datasets are available for infectious diseases, cancer, and other diseases. Especially in the case of emerging infectious disease outbreaks, clinical data obtained from a limited number of cases must be used to develop treatment strategies and public health policies. This means that many clinical data are not big data, which often makes the application of data-driven approaches difficult. In this paper, we mainly apply a mathematical model-based approach to the clinical data of COVID-19 and discuss how biologically important information can be extracted from the limited data and how they can benefit society.

South American Hemorrhagic Fever is caused by the Arenavirus, which belong to the Family Arenaviridae, genus mammarenavirus, infection at South America. South American Hemorrhagic Fever includes 1. Argentinian Hemorrhagic fever caused by Junin virus, 2. Brazilian hemorrhagic fever caused by Sabia virus, 3. Venezuelan Hemorrhagic fever caused by Guanarito virus, 4. Bolivian Hemorrhagic fever caused by Machupo virus, and 5. Unassigned hemorrhagic fever caused by Chapare virus. These viruses are classified in New World (NW) Arenavirus, which is different from Old World Arenavirus (ex. Lassa virus), based on phylogeny, serology, and geographic differences. In this review, the current knowledge of the biology and the development of the vaccines and antivirals of NW Arenaviruses which cause South American Hemorrhagic Fever will be described.

Zoonoses are caused by pathogens transmitted from animals. To prepare mitigating measures against emerging zoonoses, it is imperative to identify animal reservoirs that carry potential pathogens and also elucidate the transmission routes of these pathogens. Under the continuous collaboration with counterparts from Zambia and Indonesia, we have so far identified various viruses in wild animals. Some of the identified viruses were phylogenetically distinct from known virus species and this finding led to approved new virus species by the International Committee on Taxonomy of Viruses (ICTV). Our studies provided new insights into the divergence, natural hosts and lifecycle of viruses. Through the exploration and characterization of viruses in animals, we will endeavor to contribute to the existing knowledge on viral pathogens in wild animals. This is cardinal for evidence-based preemptive measures against future zoonoses.

Viruses achieve their efficient reproduction by utilizing their limited components (nucleic acids, lipids, and proteins) and host cell machineries. A detailed understanding of virus-virus and virus-host interactions will lead to the elucidation of mechanisms underlying viral pathogenesis and the development of novel medical countermeasures. We elucidated the details of several such interactions and their roles in the multiplication of negative-strand RNA viruses, measles virus, and Lassa virus. These discoveries were harnessed to develop a novel genetic approach for the generation of live-attenuated vaccine candidates with a well-defined molecular mechanism of attenuation. This article describes our findings.

Recently, outbreaks of highly pathogenic viruses, such as those of Ebola and Lassa viruses, have become a global public health issue. Such viruses must be handled in biosafety level 4 (BSL-4) laboratories. Currently, 62 BSL-4 laboratories are in operation, under construction, or planned in 24 counties. In this review, I provide an overview of the current status and characteristics of BSL-4 facilities in abroad and introduce my research on the wild-type Ebola virus at the BSL-4 facility in the USA.

Biosafety Level 4 (BSL-4) laboratories are required for research on microorganisms that are highly pathogenic to humans and for which there are no prevention or treatment methods. Currently, the majority of BSL-4 laboratories in more than 60 around the world are suit-type laboratories using positive pressure protective suits. In 2021, the first suit-type BSL-4 laboratory in Japan was constructed at Nagasaki University. Positive pressure protective suits are important as primary barriers to protect workers from pathogens, but the selection process has been largely unexplored. Here, I describe the selection process for the positive pressure protective suits to be used at the BSL-4 laboratory of Nagasaki University, and introduce a novel positive pressure protective suit (PS-790BSL4-AL), which was originally designed and produced in Japan.

Crimean-Congo hemorrhagic fever (CCHF) is an acute febrile illness with a high case fatality rate caused by the infection with Crimean-Congo hemorrhagic fever virus (CCHFV). The disease is endemic to a wide regions from the African continent to Asia through Europe. CCHFV is maintained in nature between Hyalomma species ticks and some species of animals. Humans are infected with CCHFV from CCHFV-positive tick bite or through a close contact with viremic animals in clucling hum am patients with CCHF. The CCHF-endemic regions depend on the distribution of the species of ticks such as Hyalomma species ticks, main vectors for CCHFV. There have been no confirmed cases of CCHF patients in Japan so far. CCHF is one of the zoonotic virus infections. Main clinical signs of the disease in humans are fever with nonspecific symptoms, and hemorrhage and deterioration in consciousness appear in severe cases. CCHF is classified in the disease category of viral hemorrhagic fevers, which include ebolavirus disease. Viral tick-borne diseases including tick-borne encephalitis, severe fever with thrombocytopenia syndrome, and Yezo virus infection, which has recently been discovered as a novel bunyavirus infection in Hokkaido, Japan, are becoming major concerns for public health in Japan. Trends of CCHF in terms of epidemiology should closely be monitored.

COVID-19 vaccination commenced globally in December 2020. Japan launched its vaccination rollout on February 17, 2021 and commenced booster vaccination campaign on December 1, 2021. It has been crucial to grasp the immune landscape in the country in order to aid in decision-making and evaluation of vaccination campaigns as well as understating the transmission dynamics of various variants of SARS-CoV-2. The present article shows a framework that enables us to predict the immune landscape, specifically, the proportion of immune population, using a mathematical modeling approach. This involved: prediction of vaccine coverage; estimation of vaccine effectiveness against the dominant SARS-CoV-2 variant in circulation; the quantification of increasing vaccine effectiveness (immune-build up) since receiving the first dose; the estimation of waning rate of vaccine effectiveness since receiving the second and third doses; and the consideration on the infection-induced immunity.