http://revach.net/article.php?id=1890

Section: Halacha   Category: Tshuvos
Rav Vosner: Bikur Cholim and Contagious Diseases

Disease transmitted through the air is not a new phenomenon.  The gemara says Rav Zeira was careful to avoid being downwind from a person with a certain disease, Rava stuffed up his window during a plague, and Rav Ami and Rav Asi wouldn't eat an egg that was in the same street as a sick person.

What about Bikur Cholim?  Are you exempt from the mitzva if the person has a contagious disease?  The Tshuvas HaRema says that worrying about catching a disease from Bikur Cholim is nonsense.  Hashem makes people sick and Hashem is the one who cures.  The Maharsham agrees with this opinion.  However the Shulchan Gavoa argues and says, "Who will listen to the Rema to endanger their life?"  The Sdei Chemed says that since there are strong opinions on both sides it is hard to take a side.  (V'Darashta V'Chakarta 4:50)

In the Shevet HaLevi (8:251), Rav Vosner argues with the logic of the Tshuvas Rema, who says that if we are scared to visit the sick the mitzva will become Batel.  Rav Vosner says that even if the mitzva would become batel we should not endanger our lives to do it.  Furthermore there are many non contagious illnesses where we can visit the sick and do the mitzva.  He therefore recommends following the Halacha of the Shulchan Aruch (YD 335:8) which says that you can be Yotzei the Mitzva of Bikur Cholim by going into a room outside of where the sick person is and inquire about what the Choleh needs.  In this way you have done your mitzva and avoided any possible danger.  

 Important Note: We try to convey the Tshuva to the best of our ability. We admit that our understanding may not be accurate. Please also understand that this Tshuva may not be the final word on this topic. One should consult a Rav before drawing any conclusions.