Leprosy Demonstrates How Fears of Disease Spread—and Then Live Forever

From Hawai‘i to China to Europe, This Ancient Malady Has Long Been a Magnet for Wider Political and Cultural Anxieties

What is it, exactly? How do you catch it? How do you diagnose it? How do you treat it? Can it be cured? If not, how do you manage it?

These difficult questions are at the heart of our fear of diseases. The story of leprosy—and about other, newer maladies—helps explain how fears spread and endure, especially within Judeo-Christian cultures.

The Book of Leviticus is a good starting point. Chapter 14 returns obsessively to the problem of distinguishing leprosy from less serious skin afflictions. How is the priest to know if …