Suspicion of conversos transferred the Jewish-doctor murder myth to them

Evidence

Since many Spaniards and Portuguese feared judeoconversos to be nothing but Jews pretending to be Christians, it was to be expected (and entirely logical) that the fear of Jewish doctors would be replaced by that of judeoconverso doctors. — James Renton, Ben Gidley (eds.), Antisemitism and Islamophobia in Europe, 378