HISTORICAL FACTS: Authorities scramble to rush out diphtheria vaccines | History Defined

* It spread to Western Australia, where 79 cases have been reported plus another six in South Australia and up to five in Queensland

* NT health authorities are awaiting results from an autopsy about a possible diphtheria-related death in a remote territory community

* Federal Health Minister Mark Butler has described it as the biggest diphtheria outbreak in Australia for decades

* The outbreak has been put down to a dip in vaccination rates, with vaccines making the disease preventable

* Health authorities are working with Aboriginal leaders and agencies to try to curb the outbreak, which has largely impacted Indigenous communities

* Diphtheria was once a leading cause of childhood death globally, according to the National Centre for Immunisation Research and Surveillance Australia

* Between 1926 and 1935 it killed more than 4000 Australians

* Diphtheria was almost eradicated by the 1950s after vaccination started in Australia in the 1930s

* It is an infection caused by a toxin from a bacteria

* It requires prompt antibiotic treatment to clear the organism and limit transmission

* Diphtheria easily spreads person to person through inhalation of respiratory droplets when an infected person coughs or sneezes

* Respiratory diphtheria symptoms can include a sore throat, mild fever, loss of appetite and in severe cases, trouble breathing, in some cases leading to death if untreated

* The less harmful strain of the disease is cutaneous diphtheria, spread by direct skin contact on lesions of infected people, with symptoms including sores or ulcers and slow-healing wounds

* Vaccination is free under a national program for children aged six weeks to two months, four months, six months, 18 months, four years and 12 years

* Pregnant women from 20 weeks of pregnancy are also eligible and adults are encouraged to get a booster vaccine every 10 years