There's something about sore throats in New Zealand that's frightening. Elsewhere in the developed world, a sore throat is just a sore throat, but here, sore throats are often caused by strep bacteria, and cause permanent heart damage in hundreds of Kiwi kids each year. Among Maori and Pacific Islanders,rates of rheumatic fever are some 10 times higher than in the rest of the New Zealand population. The disease is associated strongly with overcrowding, poverty and poor access to medical care, although genetics also play a role.
Thousands of strep throat cases go untreated each year. About 150 of these are diagnosed as rheumatic fever, which follows a strep infection. More cases go undiagnosed and are picked up only in adulthood when they cause fatigue, heart failure, infections and even premature deaths. An estimated 200 Kiwis a year die from its chronic effects. Early detection would have prevented most cases.
Strep throat doesn't directly damage your heart. Rather it convinces your body to attack itself by sending in its usual defencedefences: antibodies and T-cells. Unfortunately, strep bacteria employ molecular mimicry, with spots on their surface looking structurally identical to the coiled-coil structure of human heart muscle fibres. Our frenzied immune system attacks everything that looks like strep, including our heart valves, joints and kidneys.
Knowing all this gives scientists targets for vaccine development. Several human trials for a rheumatic fever vaccine are under way. But barring a quick fix like a vaccine, there's still hope we can rid New Zealand of rheumatic fever. Strep throat can be swabbed for and treated with 10 days of a low-cost antibiotic. The main hurdle is diagnosis. Free nurse services at low decile schools would be one way. Costs may be cited as a deterrent, but let me tell you, replacing damaged heart valves in adults is vastly more expensive than treating strep throats in kids.
• Gary Payinda M.D. works as an emergency physician, and would like to hear your medical questions. Email drpayinda@gmail.com (This column provides general information, and is not a substitute for the medical advice of your personal doctor.)
