If you start talking about scabies, it’s a pretty universal reaction to start feeling itchy.
But that impulse no longer bothers Dr Simone Reynolds.
“That’s a psychological thing that happens to most people when they either see pictures or they hear us talking about scabies. After about a couple of years of discussing it you stop getting that natural reaction!” she laughs.
Reynolds has spent the past decade studying scabies mites. She's a molecular parasitologist at QIMR Berghofer Medical Research Institute in Brisbane, and "I'm one of those weird scientists who really love parasites," she says proudly.
Inspiration from bush medicine
Reynolds, who is a descendent of the Kalkadoon people of Australia and the Koari people of Papua New Guinea, became interested in medicine and healing thanks to her grandmother, who used to practice bush medicine.
"If we had a cold or a sore or a headache or a stomach ache, she wouldn’t be saying 'go and take a Panadol', she would usually say, 'go and see if there’s any green paw paw, and she’d boil up a bit of green paw paw and get you to eat it, or a bit of pumpkin leaf or something like that," Reynolds says.
"There was always something in the garden she’d be asking you to pick, boil, eat or something, and I have good memories of it actually working, so I was always interested in making people feel better."
These days that means trying to improve the lives of Australians affected by scabies, a highly contagious skin infection caused by very small mites called Sarcoptes scabiei, which burrow into the skin to lay their eggs, causing an allergic reaction.
"The itch comes about as an allergic reaction to proteins and bits and pieces that come off the mites that are secreted into the skin," Reynolds explains. Scratching that itch can lead to developing sores, which means easy access for bacteria.
Reynolds' research is focussed on the proteins that help the mites evade detection by the human immune system and get busy laying eggs and multiplying.
"At some point there is enough stuff being left behind by the mites that the body starts to become aware of them, but by then they’ve probably well and truly established an infection and they’ve probably invited bacteria to join the party as well," Reynolds says.
She is trying to understand how many proteins scabies mites have and which parts of the immune system they engage with. This knowledge can then help to design a drug that intervenes with these proteins, helping the person to mount an immune response and kill the parasite.
More common than you think
Scabies is not a notifiable disease, so there are no exact figures on how widespread it is in Australia, but literature suggests there is an underestimation of its prevalence.
Outbreaks can occur anywhere with a concentrated population of people living or working together very closely. High schools, daycare centres, nursing homes and hospitals are prone to outbreaks.
But it also tends to be associated with communities where there is massive over-crowding and limited access to medical assistance, such as in refugee camps, during natural disasters, and in remote Aboriginal communities.
"Unfortunately in Australia [we have] pockets within the population where scabies is a daily occurrence and is endemic, and typically where we’re seeing it occurring is in Indigenous communities, mostly up north in Northern Queensland and the Northern Territory," Reynolds says.
It turns out scabies also brings along potentially related diseases.
"In the communities in the Northern Territory where scabies is endemic, the rates of rheumatic fever and rheumatic heart disease are some of the world’s highest recorded," says Reynolds. "And the bacteria that is believed to cause rheumatic fever and rheumatic heart disease are the same bacteria that you will commonly find in scabies skin sores. And that is a major major potential link."
Reducing scabies could help reduce these bacterial infections, thus potentially also limiting the spread of the life-shortening diseases of rheumatic fever and rheumatic heart disease.
"It may seem like a massive leap, but when A + B + C + D = E, if you’re able to take out A, maybe you give B less of a chance of establishing and taking hold," says Reynolds.
"We well know there is a massive health disparity particularly in Indigenous communities in remote areas anyway, so if we are able to contribute in some way to improving the health outcomes, then I’m all for it."
So while they might make your skin crawl, Reynolds finds scabies mites fascinating.
"I love what I do. I never feel like I'm coming to work, I feel like I'm coming to play," she says.
"And it really feels like I’m making some sort of true contribution to improving the long term health, not just of my own people but of anybody who suffers from scabies or rheumatic fever or rheumatic heart disease in the world."