But research of leprosy-infected chimps has so far shaped up differently. Two rare genotypes — 2F and 4N/O — have turned up in other chimps found with traces of M. leprae.

The known cases of leprosy have increased sharply in recent years.This was good, not bad, news to 250 delegates from 51 nations assembled in Rome. It meant that leprosy victims, so long shunted ...