Publications by authors named "Kazutaka Egawa"

Article Synopsis
  • This study investigates the shedding of rubella virus (RuV) by analyzing samples from 251 patients with acute rubella infection to better understand how the virus is excreted over time.* -
  • Results show that the highest levels of viral RNA were found shortly after the rash appeared, with infectious virus detectable in various samples for up to a few days post-rash onset.* -
  • The findings support improved rubella monitoring and diagnosis, suggesting that monitoring viral RNA levels can help identify infectious patients early and prevent the spread of the virus.*
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Heartland bandavirus (HRTV) is an emerging tick-borne virus that is distributed in the United States and that causes febrile illness with thrombocytopenia and leukocytopenia. It is genetically close to Dabie bandavirus, which is well known as severe fever with thrombocytopenia syndrome (SFTS) virus (SFTSV). The mortality rate of human HRTV infection is approximately 10%; however, neither approved anti-HRTV agents nor vaccines exist.

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We reported nearly complete genomic sequences of 12 serotypes of human rhinoviruses (HRVs) isolated from pediatric inpatients in Fukushima, Japan using an air-liquid interface culture of human bronchial tracheal epithelial cells. We found that various serotypes of HRV circulated locally and simultaneously from 2018 to 2021.

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  • The study reports on 10 almost complete genomic sequences of human orthorubulavirus 4, known as HPIV4.
  • These viruses were isolated from children in Fukushima, Japan, who were hospitalized with respiratory infections.
  • The researchers used a method involving air-liquid interface cultures of human bronchial and tracheal epithelial cells to obtain these sequences.
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  • The heartland virus (HRTV) is a new type of phlebovirus linked to severe infections in the USA and closely related to an Asian virus causing severe fever thrombocytopenia syndrome (SFTS).
  • Research developed a modified vesicular stomatitis virus with HRTV glycoprotein to study its entry mechanisms and interaction with antibodies.
  • Findings indicate that HRTV enters cells through a specific type of endocytosis influenced by pH and a protein called dynamin, with the potential therapeutic agent Nn-DNJ showing effectiveness in reducing HRTV and SFTSV production.
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Severe fever with thrombocytopenia syndrome (SFTS) caused by a species Dabie bandavirus (formerly SFTS virus [SFTSV]) is an emerging hemorrhagic infectious disease with a high case-fatality rate. One of the best strategies for preventing SFTS is to develop a vaccine, which is expected to induce both humoral and cellular immunity. We applied a highly attenuated but still immunogenic vaccinia virus strain LC16m8 (m8) as a recombinant vaccine for SFTS.

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Mammalian orthoreovirus (MRV), also known as reovirus, was discovered in the 1950s and became the first reported segmented double-stranded RNA virus. MRVs have since been found in a variety of animal species, including humans. However, reports on MRV infections are scarce due to the rarity of their symptomatic occurrence.

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  • The text discusses a measles outbreak in Osaka Prefecture, highlighting concerns about the development of measles in individuals who have been vaccinated with measles-containing vaccine (MCV).
  • The study involved analyzing patients’ vaccination records and clinical signs, with laboratory tests confirming 10 cases of measles, including those involving vaccinated individuals.
  • Findings suggest that one patient with two MCV doses exhibited secondary vaccine failure (SVF), indicating that even vaccinated individuals can transmit the disease, emphasizing the need for monitoring in areas where measles was previously close to elimination.
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The largest outbreak of dengue fever in Tanzania is ongoing. Dengue virus type 1 was diagnosed in a traveler who returned from Tanzania to Japan. In phylogenetic analysis, the detected strain was close to the Singapore 2015 strain, providing a valuable clue for investigating the dengue outbreak in Tanzania.

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A novel system was developed for generating highly attenuated vaccinia virus LC16m8 (m8, third-generation smallpox vaccine) that expresses foreign genes. The innovations in this system are its excisable selection marker, specificity of the integration site of a gene of interest, and easy identification of clones with a fluorescent signal. Using this system, recombinant m8s, which expressed herpes simplex virus 2 (HSV-2) glycoprotein B (gB)-, gD-, or both gB and gD (gB + gD), were generated, and their efficacy was evaluated.

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LC16m8 (m8), a highly attenuated vaccinia virus (VAC) strain, was developed as a smallpox vaccine, and its safety and immunogenicity have been confirmed. Here, we aimed to develop a system that recovers infectious m8 from a bacterial artificial chromosome (BAC) that retains the full-length viral genomic DNA (m8-BAC system). The infectious virus was successfully recovered from a VAC-BAC plasmid, named pLC16m8-BAC.

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Background: Cases of acute respiratory tract infection caused by Pteropine orthoreovirus (PRV) of the genus Orthoreovirus (family: Reoviridae) have been reported in Southeast Asia, where it was isolated from humans and bats. It is possible that PRV-associated respiratory infections might be prevalent in Southeast Asia. The clinical course of PRV is not fully elucidated.

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Article Synopsis
  • Pteropine orthoreovirus (PRV) is linked to respiratory tract illnesses in humans and was found in wild bats in the Philippines, with isolates taken from 9 of 91 bats captured in 2013.
  • The full genomic sequences of these PRV isolates show they are novel strains that have undergone genetic re-assortment.
  • A high prevalence of PRV was indicated by positive PRV-neutralizing antibodies in 76 out of 84 bats, suggesting potential importance for studying its impact on human respiratory illnesses in the region.
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Background: Severe fever with thrombocytopenia syndrome (SFTS) is a tick-borne infectious disease with a high case fatality rate, and is caused by the SFTS virus (SFTSV). SFTS is endemic to China, South Korea, and Japan. The viral RNA level in sera of patients with SFTS is known to be strongly associated with outcomes.

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