Sheikh `Abd al-Rahmân al-Jar`î, professor at King Khâlid University in Abhâ
Islam most certainly does not deny the existence of contagious diseases. In fact, the Prophet (peace be upon him) commanded us to avoid such diseases. He said: “Run away from the leper same as you would from a lion.” [Sahîh al-Bukhârî (5707) and Sahîh Muslim (2220)].
He also said: “The person who has a contagious disease should not approach a healthy person.” [Sahîh Muslim (2221)]
In fact, Islam preceded modern societies by establishing the idea of quarantines. The Prophet (peace be upon him) said: “If you hear that a land has been stricken by plague, do not approach it, and if your land is stricken by plague, do not leave it”. [Sahîh al-Bukhârî (5728)]
It is well-known that plague is contagious and the hadîth therefore gives us a general warning against all contagious diseases.
It is true that the Prophet (peace be upon him) said: “There is no contagious disease, no intestinal serpent, and no omens in worms.”
To this, a desert dweller said: “O Messenger of Allah! What about the camels that can be in the desert as healthy as gazelles. Then a camel afflicted with a skin disease joins them and the whole lot falls ill?”
The Prophet (peace be upon him) replied: “Who made it so that the first camel got infected?” [Sahîh Muslim (2220)]
This hadîth does not contradict with the other hadîth that we have previously mentioned. A Muslim believes that it is Allah, and not the other infected person, who causes the disease to afflict someone. Two people might be exposed to a deadly microbe while only one falls ill. The reason for this might be the difference in the strength of the immune system enjoyed by each person. The statement “no contagious disease” means that a contagious disease will not affect a person except with the permission of Allah, for indeed Allah is the one who causes all natural causes. This is what every Muslims should believe.
The person who becomes infected with a contagious disease should refrain from going to the mosque to avoid transferring his disease to others. Disease is harmful and it should be avoided, as clearly stated in many authentic hadîth where the Prophet (peace be upon him) said “Harm should be removed.”
A Muslim will not be sinful for abandoning congregational prayer in the mosque under such circumstances, because sickness is something beyond his control.
And Allah knows best.
Source: Islam Today