DARWIN, June 15 -- Diphtheria was supposed to be a disease of the past, the kind of illness that crowds Victorian-era death registers and then all but vanishes from the record. In remote communities across Australia's Northern Territory this year it came back, and for the first time in nearly a decade it killed someone.

Australia has now recorded 245 cases of diphtheria in 2026, the worst outbreak since national records began their modern count in 1991. The bulk of them, around 163, have been in the Northern Territory, many in remote Indigenous communities where the disease found exactly the conditions it needs. The single confirmed death has turned a public-health problem into something officials are willing to call a tragedy.

What mak...