| 研究実績の概要 |
Last fiscal year, we analysed rotavirus strains circulating pre-and post-April 25, 2015 earthquake period as planned besides continuing with our pre-vaccination part of rotavirus molecular epidemiological studies. Out of 255 and 348 diarrhoeal samples collected pre-and post-earthquake period respectively (January to mid-September 2015), 118 Rotavirus A positive samples were subjected to polyacrylamide gel electrophoresis (PAGE). Of the 85 which could be electropherotyped, 42 G12P[6] strains were classified into 7 different electropherotypes. Among the 7, one attributing to 50% of circulating G12P[6] strains was identified as predominant with the second common strain detected at 12%. Furthermore, the predominant strain was found to be distributed equally before and after earthquake. Whole genome analysis by electropherotyping revealed that this strain along with one minor co-circulating strain had RNA profile similar to those of 2 predominant strains detected during 2005-2011. Overall, no major changes were observed among the circulating rotavirus strain detected before and after 2015 earthquake. However, the observation we made in this study has given us further understanding as to how G12P[6] strains are constantly evolving in Nepal since strains which were detected in the 2005-2011 study period 1) seemed to have made a comeback in 2015 after 3 years’ gap or, 2) continuously been circulating since 2011. Thus this study has helped us to further solidify previous conclusion we made on the continuous evolution of rotavirus strains within the same G12P[6] genotype.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
3: やや遅れている
理由
For the pre and post 2015 earthquake collection of the rotavirus strains, whole genome analysis by electropherotyping has been completed, and the representative strains have been shortlisted for their whole genome analysis at the nucleotide sequence level. The post vaccine part of the study could not be performed last year as planned as the vaccination schedule was postponed till July this year. Site visit and technology transfer at the collaborating laboratory in Nepal was done as planned and the research questionnaire was revised with the rotavirus vaccine related information.
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| 今後の研究の推進方策 |
Next, we would like to carry out whole genome sequence analysis for the shortlisted representative strains to see if the result obtained in this study would be supported at the nucleotide sequence level as well. Furthermore, this fiscal year, as the introduction of rotavirus vaccine is scheduled in July 2018 in Nepal nationally, we will carry out our plan to set up surveillance system for monitoring vaccine impact on the diarrhoeal disease burden due to rotavirus and any possible changes in the circulating strains.
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