A study to identify and better understand risk factors for rheumatic fever – one of New Zealand's most mysterious and serious illnesses – starts recruiting participants in Auckland this week.
Over the next two years the University of Otago, Wellington “case-control” study aims to recruit 200 children and teenagers with rheumatic fever, and compare them with 400 young people who do not have the disease, to identify important risk factors.
Initially being run in Auckland, the study will extend to Northland, Waikato and possibly to other parts of the North Island depending on disease incidence and recruitment rates, says lead researcher Professor Michael Baker. Results will be available towards the end of 2016.
Planning for the study began at the end of 2013 and it has taken many months to design, consult, obtain ethical approval, set up, and finally reach the point where recruitment can begin, Professor Baker says.
The study has been deliberately designed to investigate a full set of potentially modifiable risk factors for rheumatic fever. There is a particular focus on household crowding, sleeping arrangements, home heating, washing facilities, tobacco smoke exposure, dental health, health care access and nutrition, including plausible risk factors such as vitamin D deficiency, he says.
“Rheumatic fever is a mysterious disease. We don't really know much more than we did in the 1950s about its causes – in particular, why most people with a strep sore throat get over the infection, and only a tiny fraction develop acute rheumatic fever and chronic rheumatic heart disease that kills about 150 New Zealanders a year. Our aim is to fill some of these knowledge gaps which currently limit our ability to develop and implement effective interventions.”
The rising incidence of rheumatic fever in New Zealand, particularly in Māori and Pacific children, is another big mystery, Professor Baker says.
In 2013 there were 205 notified cases, the highest total in more than 20 years, and 95% of those cases were in Māori and Pacific children, an incidence Professor Baker says is “totally unacceptable”.
Because rheumatic fever virtually vanished from the United States and Europe in the 1960s, it has received surprisingly little attention from researchers, despite remaining an important disease across the developing world, Professor Baker says.
“There have been very few high-quality case-control studies of the type we are conducting. Consequently, results of this New Zealand study have the potential to support global efforts to control rheumatic fever.”
He does admit, however, to feeling a bit anxious about the study.
“Case-control studies are unforgiving. You have to identify all of your hypotheses and risk factors at the start and build them into your data collecting and testing. There are no second chances. Fortunately, we have a brilliant group of co-investigators, and Māori and Pacific advisory groups who have given us expert guidance about the study design and questions that we need to focus on.”
The study team includes paediatricians, microbiologists, immunologists, and geneticists as well as experts in epidemiology, oral health and housing. In what Professor Baker describes as “very much a national effort to try to understand the disease”, team members are based at the University of Auckland, Environmental Science and Research (ESR) and the Auckland District Health Board, as well as the University of Otago.
The research team is also grateful for the high level of support it is getting from doctors, nurses and laboratory scientists, Professor Baker says.
“This support is critical for the success of the study. There is a lot of good will towards this research because of the recognition that we currently don't know how to stop this disease.”
The study is funded by the Health Research Council of New Zealand, the Heart Foundation, Cure Kids, Te Puni Kokiri, and the Ministry of Health.
For further information contact:
Professor Michael Baker
Department of Public Health
University of Otago, Wellington
Tel 64 4 918 6802
Email michael.baker@otago.ac.nz
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