I Googled Lewontin and the sentence you mentioned and got the following exchange in letters column from 1983:

This is a discussion of Lewontin's

which seems to be:

One of these should have what you need.


-----Original Message-----
From: Carrol Cox <[log in to unmask]>
To: SCIENCE-FOR-THE-PEOPLE <[log in to unmask]>
Sent: Fri, Jun 29, 2012 10:48 pm
Subject: Query

Years ago there was an article by Richard Lewontin in the NYRB which, among
other things, pointed out that the statement "Germs cause disease" was
incorrect. Of course in an issue or two there was a lively dispute in the
letters over that. I'm sure I downloaded the article, but I can't find it. I
don't remember the title or which decade it was published in. If someone can
help me on this I will be grateful.