*	http://idsc.nih.go.jp/iasr/23/265/kj2651.html
**	http://www.cdc.gov/ncidod/EID/vol9no6/pdfs/Vol9No6.pdf
***	http://idsc.nih.go.jp/iasr/27/315/kj3152.html
****	http://idsc.nih.go.jp/iasr/27/322/dj3223.html