Dr Toakase Fakakovikaetau, third from right, established the 'Mafu Sai' (Good Heart) screening programme in 2008. To her right is Pacific epidemiologist Dr Gerhard Sundborn. Photo: Supplied
There are calls for more efforts to eliminate scabies in Tonga in order to reduce the incidence of rheumatic heart disease in local children.
This comes as a study from the University of Auckland found a strong link between scabies and rheumatic heart disease in Tongan schoolchildren.
Researchers screened 400 children from four Tongatapu schools. They found that children with both scabies and a bacterial skin infection were almost five times more likely to have rheumatic heart disease compared with children with healthy skin.
"That's a really high association relative risk," said one of the researchers, Pacific epidemiologist Dr Gerhard Sundborn, who explained that he and Dr Simon Thornley had been studying the link between scabies and heart disease for almost 8 years.
"Every study that we do, the strength of the relationship only increases. And so we think that it indicates that scabies is a causal mechanism in rheumatic heart disease."
Easily preventable
Scabies is easily treated, Dr Sundborn said. It is generally treated with permethrin cream or ivermectin tablets.
"But the only difficulty is if there's a high prevalence, you need to treat the whole population. For communities or populations where there's a prevalence that's over ten percent, the World Health Organisation recommends mass drug administration, treating their whole population at the same time."
Mass drug administration using ivermectin has previously worked well in the Pacific in countries like Fiji to cut scabies rates substantially within two years. Dr Sundborn is hopeful that could be replicated in Tonga.
"We treat the scabies and get rid of the scabies, and monitor that population for two or three years. And what we hope we will see is that the disease incidence, new cases, will stop, or there will be a drastic reduction."
The study was conducted in collaboration with New Zealand's Health Research Council and with the Tongan Ministry of Health and Tonga National University.
Fakakovikaitau's legacy
The study drew on the long-running Mafu Sai programme which has annually screened about 5000 primary school kids in Tonga over the course of two decades.
This programme was initiated by the late Dr Toakase Fakakovikaitau. Sundborn said that Dr Fakakovikaitau did a study in 2003 that found a high prevalence of rheumatic heart disease in primary school children in Tonga.
"When I met her (in 2023) and I explained the theory around scabies being the causal factor to rheumatic heart disease, she was immediately drawn in. It made sense to her," he said.
The latest findings are a testament to Dr Fakakovikaitau's important work, both her published findings on scabies and her efforts to initiate the Mafu Sai programme.
Meanwhile, the researchers plan a pilot project on a small island near Tongatapu with about 5000 residents, where they want to carry out mass treatment to eliminate scabies and then monitor new cases of rheumatic fever and rheumatic heart disease over several years.
The pilot project will however depend on funding, but the researchers hope that, working with the Ministry of Health Tonga, this approach - if proven successful - could transform prevention strategies across the Pacific.