The current diphtheria outbreak - which has spread across four Australian states and possibly claimed one man's life - may seem unexpected.
But a closer look shows it is yet another example of inequitable systems - including inadequate housing, a lack of washing facilities and under-investment in preventive health care - driving the spread of infectious disease in Australia's remote communities.
For decades, groups such as the National Aboriginal Community Controlled Health Organisation - Australia's national authority on Aboriginal and Torres Strait Islander health care - has urged authorities to address these issues.
So why do they still exist? And can we fix them?
An historic outbreak
Diphtheria is caused by toxin-producing bacteria, Corynebacterium diphtheriae.
This potentially fatal disease can spread between people through respiratory droplets, or direct contact with infected wounds, skin sores or bodily fluids.
In this latest outbreak, roughly 70% of cases have presented as cutaneous (skin) diphtheria and about 30% as respiratory (throat) diphtheria.
Cutaneous diphtheria is usually less severe, but remains a public health concern as skin sores can facilitate the spread of the disease.
Respiratory diphtheria is the form most associated with severe illness and death.
As of 25 May, authorities say there has been one possible death related to diphtheria in the Northern Territory. The latest data shows Australia has recorded more than 230 diphtheria cases since January 2026.
The federal government recently pledged A$7.2 million to help curb this outbreak, working in close collaboration with the National Aboriginal Community Controlled Health Organisation.
However, we are not only concerned about diphtheria itself, but the inequitable conditions that may help it spread.
Why is it spreading so quickly?
We believe the conditions contributing to the high rates of skin infections in remote Australia are driving this historic diphtheria outbreak.
Remote Aboriginal communities face high rates of preventable skin sores , which can cause severe diseases including sepsis, acute rheumatic fever and rheumatic heart disease .
These sores, generally caused by Streptococcus pyogenes and Staphylococcus aureus, are preventable. But doctors and health care workers may miss them , especially if they are working in busy, under-resourced remote clinics.
Certain environmental factors may allow skin sores, and related diseases such as diphtheria, to spread more rapidly in First Nations communities.
One is insufficient housing . A lack of safe, clean housing may cause infectious diseases - such as strep, staph and diphtheria - to spread more quickly from person to person. In remote communities, this can happen in households, in schools and at community events .
Another environmental factor is overcrowding. Overcrowding puts pressure on home plumbing systems, meaning blocked toilets, broken taps and leaking pipes become more common . If people can't wash their hands or bodies, this increases their risk of getting infectious diseases such as diphtheria. Research shows even simple hygiene practices, such as handwashing with soap and water, reduces skin sores.
Many remote households also struggle to access basic maintenance or repair services. Even basic jobs, such as fixing a leaking tap, washing machine or a broken hot water system, may take weeks or months. This has direct health impacts, as people may not have the water or facilities to wash themselves or their clothes.
So, what can we do?
In the current outbreak, vaccine boosters are essential to preventing severe illness and death. But long-term, vaccines alone won't stop the spread of diphtheria and other infectious diseases.
For that, we need to fix our systems. Research suggests public health responses tend to focus on specific diseases, instead of the structural problems that drive their spread.
So to prevent future diphtheria and other outbreaks, we need to invest more in remote communities. We must build and maintain homes that have the space, water and washing facilities to keep people clean and healthy at home. We also need to make hygiene and cleaning supplies more affordable by aligning prices in remote communities with those in urban areas .
We must also involve First Nations communities in all public health initiatives. In many cases, remote communities already know the solutions to the issues they face. This was evident during the COVID pandemic , when Aboriginal leaders spearheaded the public health response in remote communities. As a result, Australia recorded far fewer Indigenous deaths than other countries.
Sitting with and listening to our First Nations communities takes time. But it demonstrates a commitment to working together, and is key to making public health responses as effective and sustainable as possible.
Asha Bowen receives funding from the National Health and Medical Research Council of Australia and the Medical Research Futures Fund of Australia.
Lorraine Anderson is affiliated with RACGP and AMA.
Stephanie Enkel does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
