Two different dengue virus strains in the Japanese epidemics of 2014.

In late August 2014, dengue cases were reported in Japan, and a total of 162 cases were confirmed. In the present study, the envelope (E) gene sequences of 12 specimens from the dengue patients were determined. A dengue virus serotype 1 (DENV1) strain (D1/Hu/Shizuoka/NIID181/2014), which was clearly different from the first reported strain (D1/Hu/Saitama/NIID100/2014), was identified, although the other 11 specimens showed the same nucleotide sequences as D1/Hu/Saitama/NIID100/2014. The E gene sequences of two different strains were compared with those of nine DENV1 strains of imported cases in Japan in 2014. Phylogenetic analysis based on the E gene sequences showed that the D1/Hu/Saitama/NIID100/2014 strain was closely related to a strain isolated from an imported case from Singapore. Although no strain closely related to D1/Hu/Shizuoka/NIID181/2014 was found in these imported strains, the strain was closely related to isolates in Thailand and Taiwan in 2009. These data indicate that the dengue cases in Japan were caused by two different dengue virus strains that entered Japan through different means.

Discussion on effect of material on UV reflection and its disinfection with focus on Japanese Stucco for interior wall.

Research has previously shown that ultraviolet light C (UV-C) can inactivate unexpected infection. However, this type of potential disinfection is dramatically reduced for the shadow area such as under desk or medical equipment. Because the UV-C reflectance ratio is low on the general wall surfaces. We compared Stucco against the other materials to investigate whether we could improve disinfection for the shadow area. The reflectance ratios of UV-C irradiation of each material were examined, with particular attention to the rates for the author's Modified Stucco. To evaluate the disinfection effects of the UV-C reflective lighting, colonies of E. coli and of Staphylococcus hominis were cultured in an agar media and counted over a certain time period after applying UV-C irradiation from a sterilizing lamp onto the investigation materials. The author's Modified Stucco, produced reflectance ratios that was 11 times that of white wallpaper. This demonstrated that the UV-C reflected on the Stucco wall having optimum components and their compositions inhibited the number of E. coli and S. hominis, resulting in significantly disinfection effects on white wallpapers. The space with Modified Stucco and then irradiated by a UV-C may give a strong disinfection effect.