the shade [of illness] next above it [yellow fever], called the stranger’s fever has been coeval [contemporary] with the settlement of the larger cities in the Southern parts, to wit, Norfolk, Charleston, New Orleans. strangers going to these places in the months of July, August or September, find this fever as mortal as the genuine yellow fever. but it rarely attacks those who have resided in them some time.
From Thomas Jefferson to Constantin François Chasseboeuf Volney, February 8, 1805
In the face of coronavirus, I’m excerpting correspondence about diseases that ravaged the nation in Thomas Jefferson’s time.
Patrick Lee’s Explanation
Sometimes, leaders don’t understand what’s happening or why.
Excerpted from a longer, complicated passage in this letter to his French scientist/philosopher friend, the President introduced a malady called “stranger’s fever.” Very much like the yellow fever in its symptoms and mortality, it attacked only newcomers, i.e. strangers, to southern coastal cities. The locals were rarely affected. The yellow fever attacked everyone.
Jefferson didn’t make the claim or explain, but perhaps he was describing a natural “herd immunity” enjoyed by the locals, built up over time.
He went on to propose his disease-thwarting “checkerboard plan” for urban development, described in several earlier posts in this series.