Submitted on: 06 February 2005.
Revised on: 10 March 2005.
Accepted on: 22 March 2005.
Open Forum Infectious Diseases
http://reply.papertrans.cn/3/237/23643/23643-32.png
http://reply.papertrans.cn/3/237/23643/23643-33.png
Submitted on: 04 March 2012.
Revised on: 29 March 2012.
Accepted on: 06 April 2012.
Open Forum Infectious Diseases
http://reply.papertrans.cn/3/237/23643/23643-35.png
http://reply.papertrans.cn/3/237/23643/23643-36.png