![](/fileadmin/_processed_/3/4/csm_5737_eac9d2d8ea.jpg)
29. November 2010
![](/fileadmin/_processed_/2/1/csm_5733_2291cd7318.jpg)
29. November 2010
![](/fileadmin/_processed_/8/f/csm_5744_25e17da814.jpg)
29. November 2010
![](/fileadmin/_processed_/1/9/csm_5732_78529018ae.jpg)
29. November 2010
![](/fileadmin/_processed_/a/5/csm_5748_4ea9042b08.jpg)
29. November 2010
Research: Long and close contact is a pre-condition for infection
29. November 2010
29. November 2010
29. November 2010
29. November 2010
29. November 2010
Research: Long and close contact is a pre-condition for infection