AIDS

Khan is studying in the west as he is calling his mom:

KHAN: Mom, I have AIDS.

Mother: Don't come back my son.

KHAN: Why Mom?

Mother: If you come back then your wife will be infected.
From your wife to your brother, from your brother to our maid, from our maid to your dad, from your dad to my sister and from my sister to her husband, from him to me and from me to our driver, from our driver to your sister and if your sister got AIDS, then...the whole village will be infected!

So in the name of god please save our village. Don't come back!..