Rheumatic fever: a disease of poverty New Zealand has not solved

Panels reach for this because it is the clearest case in New Zealand medicine of a disease whose distribution is decided by social conditions rather than by biology, and because the causal chain is short enough to state completely in an interview answer. A candidate who can walk that chain has demonstrated more about their understanding of health equity than any general statement could.

Here is the version worth holding. Every other wealthy country has largely eliminated this disease, not by inventing anything but by having warm, uncrowded houses and accessible primary care. New Zealand has the same antibiotics and the same knowledge and a persistently higher rate, which means the failure is not clinical. That sentence is the whole argument.

A child acquires group A streptococcus, usually as pharyngitis and in some settings via skin infection. In a small proportion of untreated cases, and typically two to four weeks later, the immune response goes wrong: antibodies raised against streptococcal antigens cross-react with human tissue that resembles them — a process called molecular mimicry. The result is acute rheumatic fever: fever, migratory arthritis of the large joints, carditis, and less commonly chorea, subcutaneous nodules and erythema marginatum. The Jones criteria are used to diagnose it.

The joints recover. The heart may not. Inflammation of the valves — most often the mitral, then the aortic — can leave scarring and distortion that progresses over years into rheumatic heart disease, causing stenosis or regurgitation, heart failure, atrial fibrillation, stroke and the need for valve surgery, often in a person’s thirties or forties. Recurrent episodes worsen the damage, which is why anyone who has had rheumatic fever receives secondary prophylaxis: regular intramuscular benzathine penicillin, typically monthly for a decade or more. That injection is painful, and asking a teenager to attend for it every month for years is a genuine adherence problem, not a trivial one.

Two conditions have to hold for the chain to complete, and New Zealand supplies both for a specific population.

Transmission. Group A streptococcus spreads through close contact, and household crowding is its ideal environment — several children per bedroom, shared bedding, damp and cold housing that also drives respiratory infection generally. New Zealand’s housing stock is poorly insulated by international standards, rental quality has been a long-running policy problem, and crowding is concentrated in Māori and Pacific households in the largest cities.

Untreated infection. The sore throat has to go unseen or untreated. That is a primary care access problem: a co-payment for a child over 14, a practice with closed books, a long distance, work that cannot be missed, and — not least — a service the family may not expect to be treated well by. A sore throat is also a trivial-seeming complaint, so the threshold for taking a child to a doctor about one is high unless a family knows why it matters.

The result is a disease whose incidence maps almost exactly onto deprivation and ethnicity. It is not that Māori and Pacific children are more susceptible; it is that they are more likely to live in the conditions where the chain completes. Saying it that way round is important, and panels notice which way a candidate says it.

Sore throat programmes. The best-known response placed throat swabbing and treatment in schools in high-incidence areas, so that a child with a sore throat could be swabbed and treated without a parent needing to take time off or pay a fee. Rates fell during the most intensive period of the programme and the approach demonstrated the principle — take the service to where the children are. Coverage and funding have varied since, and the honest assessment is that the gains were real and not sustained everywhere.

Free primary care for children. Extending free general practice visits to children removed the fee barrier for younger children, which matters for exactly this condition.

Housing. Insulation and heating programmes, healthy homes rental standards and efforts to reduce crowding attack the transmission side. This is the slowest lever and the one with the strongest theoretical claim, because it addresses the condition that makes the whole chain likely.

Secondary prophylaxis registers. Systems to track and deliver monthly penicillin to people who have already had rheumatic fever, which prevents recurrence and is the difference between one episode and progressive valve destruction.

A candidate who names one lever from the transmission side and one from the treatment side, and says which they would fund first and why, is arguing at the level a panel wants.

This arrives in three shapes. The direct one: "Why does New Zealand still have rheumatic fever?" The equity one: "Give me an example of a health inequity in New Zealand." And the disguised one — "What are the social determinants of health?", where this is the concrete example that beats any list.

For the direct question, walk the chain from throat to valve and stop at the two failure points. For the equity question, use this rather than a general statement. For the determinants question, use housing specifically.

Start with the Ministry of Health and Te Whatu Ora pages on rheumatic fever for the New Zealand data and the prevention programmes, then the Heart Foundation’s guidelines on diagnosis and secondary prophylaxis for the clinical detail. One evaluation of the school-based sore throat programme gives you the evidence on what worked and what did not persist.

Two pieces here give you the surrounding system. Māori health equity is the wider frame this sits inside, and the GP shortage is the access failure that leaves the throat untreated. For the interview formats, see our New Zealand interview guides.