tetano
Editor, Senior Moderator
At least 28 genetically different types of the H1N1 swine flu virus have entered Japan since the time of the outbreak last spring to late September, researchers at the Infectious Disease Surveillance Center said Wednesday.
The first types of the "new" virus, which spread through Kobe and Osaka in the initial phase of Japan's outbreak last May and eventually became a pandemic, are believed to have been eradicated because of widespread school closures and other measures quickly taken to halt its spread, the results of an analysis indicate.
A team led by Teiichiro Shiino, the institute's chief researcher, analyzed the genetic base sequence of 238 specimens, including 75 samples of the flu collected between May 8 and Sept. 20 in Japan and 163 collected worldwide. Locally, the flu is called "shingata infuruenza," or new-type flu.
According to Shiino's results, the virus can roughly be divided into four major types, including the one detected in Mexico and the southern United States, where the outbreak likely originated, one found in New York and other places, and two other types formed by the crossing of the other two types.
Shiino's team further divided the virus into 28 types based on marginal genetic differences, including 12 linked to a mass outbreak and 16 more detected in individuals.
The 28 types are believed to have entered Japan independently from abroad. There is also a high probability that the types detected in mass outbreaks penetrated Japan between late May and early June, the team said.
http://search.japantimes.co.jp/cgi-bin/nn20100528f4.html
The first types of the "new" virus, which spread through Kobe and Osaka in the initial phase of Japan's outbreak last May and eventually became a pandemic, are believed to have been eradicated because of widespread school closures and other measures quickly taken to halt its spread, the results of an analysis indicate.
A team led by Teiichiro Shiino, the institute's chief researcher, analyzed the genetic base sequence of 238 specimens, including 75 samples of the flu collected between May 8 and Sept. 20 in Japan and 163 collected worldwide. Locally, the flu is called "shingata infuruenza," or new-type flu.
According to Shiino's results, the virus can roughly be divided into four major types, including the one detected in Mexico and the southern United States, where the outbreak likely originated, one found in New York and other places, and two other types formed by the crossing of the other two types.
Shiino's team further divided the virus into 28 types based on marginal genetic differences, including 12 linked to a mass outbreak and 16 more detected in individuals.
The 28 types are believed to have entered Japan independently from abroad. There is also a high probability that the types detected in mass outbreaks penetrated Japan between late May and early June, the team said.
http://search.japantimes.co.jp/cgi-bin/nn20100528f4.html