Is it Dangerous to Kiss a Mezuzah ?

The Rambam in the sixth chapter of Hilchos Mezuzah writes :

Whenever a person enters or leaves his home, he will encounter the unity of Hashem's Name. He will then be reminded of his love for Him, and will be awakened from his slumber and the error of being absorbed in trivial activities. He will then know that only knowledge of Hashem is permanent, and will immediately return to his own awareness, and follow the paths of the upright...

I assume that the basis of the custom to kiss the mezuzah(I would appreciate any sources * regarding this) is to bring to awareness thoughts and feelings, such as those described by the Rambam.

The following is a link about one Conservative rabbi's ruling, which recommended not kissing the mezuzah, out of concerns of spreading infectious disease. Now, were the level of concern of a health hazard to reach a serious threshold, I assume Orthodox poskim would, as well, advise against kissing a mezuzah and categorize the act as "shachiach hezeika".

Practically, I don't know to what extent this ruling will be followed by Conservative Jews who have been observing the custom to kiss the Mezuzah.

* Note: See gemera Avodah Zarah 11a, as noted in comments.