Heart checks show 'alarming' fever rate

Previously undiagnosed cases of rheumatic fever blamed for heart damage. Photo / Thinkstock

A study of New Zealand children's hearts has uncovered an "alarming" rate of damage caused by what many call a Third World disease.

The study in Northland found that nearly one in a hundred children had heart damage caused by previously undiagnosed rheumatic fever.

"I find 1 per cent quite alarming," Northland's medical officer of health, Dr Jonathan Jarman, said yesterday. "It's heart damage caused by a preventable disease; it's a Third World disease.

"[The study] shows the rheumatic fever problem in Northland is worse than thought."

Rheumatic fever is an immune system reaction to a sore throat caused by group A streptococcal bacteria. It can cause muscle and joint pain - and potentially fatal heart damage. It is linked to household overcrowding.

Public health physicians urge parents to get their children checked by a doctor if they have a sore throat, especially if they are Maori or Pacific Islanders, or live in poorer areas of the North Island.

A sore throat can also be caused by a viral infection, but Dr Jarman said: "It's better to be safe than sorry."

A strep throat can be treated with antibiotics.

The rates of rheumatic fever among young people are far higher for Maori (23 times) and Pacific Islanders (49 times) than other ethnic groups.

The Counties Manukau health district has New Zealand's highest rheumatic fever incidence, central Auckland the second-highest, then Northland, Bay of Plenty, Lakes, Tairawhiti (Gisborne area), Hawkes Bay and Hutt Valley.

In the Northland study, 693 Kaitaia children aged between 9 and 13 had their hearts checked with an echocardiogram scanner.

Seven were found to have heart damage caused by previous rheumatic fever and 13 were found to have inconclusive or borderline rheumatic heart disease. A further 18 were found to have congenital heart disease unrelated to rheumatic fever, three of whom have significant disease and were referred for treatment.

Those with confirmed rheumatic heart disease will be given monthly antibiotic injections long term.

Those with unconfirmed rheumatic heart disease will be monitored.

One of the researchers, Starship children's hospital cardiologist Dr Nigel Wilson, said earlier studies, in the Bay of Plenty and Tairawhiti, had also shown that about 1 per cent of children scanned had heart changes highly suggestive of previous rheumatic fever. But in South Auckland, the rate was far higher, at 2.5 per cent.

He hoped echocardiogram screening to detect rheumatic heart disease would become an established practice, but said the biggest potential gains against rheumatic fever were in reducing household overcrowding and in detecting and treating strep throat.