Nigel Wilson: Hidden scandal of rheumatic fever a costly timebomb

One rheumatic fever control programme involved throat swabbing children, with a good success rate. File photo / NZ Herald

Sir David Skegg's recent article on the history of cervical cancer in New Zealand concluded that screening saves about 100 lives a year.

He rightly points out that many of those being saved "would have died in middle age, often with young children in their care". This has been achieved by a national screening programme as a direct outcome of the Cartwright Inquiry, due to the "dedication of many people, including health professionals and women's groups".

In other words, public health action was driven by reaction to heightened public awareness of cervical cancer. Dr Skegg went on to mention other unmet public health challenges such as rheumatic fever.

Rheumatic fever is a complication of a streptococcal bacterial throat infection and most commonly affects school-aged children. A few weeks after a streptococcal throat infection a child may develop sore joints or arthritis, along with inflammation of the heart valves. The disease "licks the joints and bites the heart". The joints get better but, especially with recurrent attacks, heart damage can be permanent and severe (rheumatic heart disease).

In most developed countries rheumatic fever disappeared in the mid-20th century but in New Zealand rates have remained high. However there are great ethnic disparities. Rates among Maori and Pacific children are currently 30 and 77 times higher than in Pakeha, despite no proven genetic susceptibility to rheumatic fever.

It is likely that this over-representation is due to overcrowding, poverty and decreased access to primary healthcare.

Failure to prevent rheumatic fever means rheumatic heart disease will be a burden for decades to come for Maori and Pacific communities and for health services. Cardiac surgery is hugely expensive.

The Government agency Pharmac produces pamphlets to remind GPs about differentiating viral from bacterial infections. The aim to reduce inappropriate antibiotic prescriptions is laudable but does not take into consideration that untreated streptococcal sore throat infections pose a risk of rheumatic fever for the 30 per cent of our children who are Maori or Polynesian.

Guidelines for the recognition and treatment of sore throats have recently been published by the Heart Foundation at www.nhf.org.nz and must be implemented by health professionals. Pharmac could amend its "one policy fits all" campaign to GPs. Not all streptococcal throat infections cause symptoms so active throat swabbing programmes are also needed in high-risk populations.

Professor Diana Lennon has recently calculated by meta-analysis of published research that up to 60 per cent of acute rheumatic fever cases could be prevented by throat swabbing programmes. Primary prevention has already been shown to work in Whangaroa, Northland. Rising concern about rheumatic fever rates led to the local community, in partnership with Dr Jonathan Jarman from Northland Public Health, initiating a throat swabbing programme for 500 children. With community involvement no new cases of rheumatic fever occurred over the following seven years.

Other successful rheumatic fever control programmes have used multiple approaches including improving access to health clinics and community education about the illness.

Yet not all cases of rheumatic fever present with sore joints or arthritis. Episodes of rheumatic fever may be silent, affecting the heart but not producing symptoms.

These people present as adults with a failing heart, sometimes in pregnancy. Others present with infections of the heart or a stroke due to abnormal heart rhythms coming from an overstretched heart.

Recent research using compact portable echocardiography shows great promise to detect those with silent or asymptomatic rheumatic heart changes. In 2007-8 I worked with Dr Rachel Webb, paediatrician, and a team from Counties Manukau District Health Board. We found that 2.4 per cent of 10- to 13-year-old children in low decile schools had rheumatic heart changes.

Giving long-term penicillin therapy to these children will dramatically reduce the chance their adult lives will be ruined by rheumatic heart disease. Such programmes need skilled cardiologists to interpret the echocardiograms in the same way that cervical smears need to be examined by skilled pathologists.

In conclusion, the history of our efforts to reduce rheumatic fever is in dramatic contrast to cervical cancer, despite both of these diseases causing similar numbers of largely preventable deaths.

If rheumatic fever was occurring unabated in St Heliers, Karori and Fendalton it would undoubtedly be a major public health issue. Do we need another Cartwright Inquiry to drive public health action on rheumatic fever?

* Dr Nigel Wilson is a children's heart specialist in Auckland.