no/nein!

a quick wiki-check should be obligatory before posting such misinformation:
smallpox (dt. Pocken):
"a leading cause of death in the 18th century, killing an estimated 400,000 Europeans each year"
vaccination starting around 1800 in european countries, and this dramatically improved the situation so that the last outbreaks in europe were around 1970 and the virus is completely eradicated today.
This is just an effect of the vaccine, and has nothing to do with housing conditions.

Similar stories for measles etc.