Game of Thrones prequel House of the Dragon has got people talking about leprosy. Following recent episodes of the hit show, fans have been wondering what mystery illness could be affecting King Viserys, causing him to develop sores on his skin and suffer from deteriorating health.

Paddy Considine, who plays Viserys, has recently explained that his character is suffering with leprosy. In an interview with Entertainment Weekly's West of Westeros podcast, he revealed: “He’s actually suffering from a form of leprosy. His body is deteriorating, his bones are deteriorating. He is not actually old. He’s still a young man in there. He’s just, unfortunately, got this thing that’s taken over his body. It becomes a metaphor for being king, and the stress and strain that it puts on you, and what it does to you physically, what it does to you mentally.”

So how does Viserys' condition compare to the reality of leprosy today? And how accurately has the disease been portrayed? We answer some common questions.

Is leprosy very infectious?

Lots of people are wondering why King Viserys' wife, Alicent, doesn't seem to have contracted his illness too. It's easy to assume that leprosy is easily passed on from person to person but in fact, it is only a mildly infectious disease. Globally, around 95 per cent of people are immune to it. It's most likely that leprosy is spread through the air, by moisture droplets passed on by coughing and sneezing. It cannot be caught by touch and it not hereditary.

What are the symptoms?

Leprosy starts by damaging the nerves closest to the skin. The first signs of the disease are often paler patches of skin that have lost sensation. If left untreated, this can lead to injuries, which then cause ulcers, and muscle paralysis that can affect hands, feet and eyes. Leprosy is not a fatal illness, but it can cause a lot of complications that can severely affect people's health.

Does leprosy still exist?

Absolutely! Many people don't realise that in recent times, around 200,000 people have been diagnosed with leprosy each year. But there are many more people living with the disease who have not yet come forward for treatment. This is often because they don't recognise the first symptoms as something serious. In many of the countries we support, people often live far from a clinic or hospital. And the stigma of the disease means that when some people suspect they have leprosy, they avoid seeking treatment in case their friends and families find out.

Can it be cured?

Yes - Multidrug therapy, the cure for leprosy, was first used in 1982. Someone affected by the disease must take a course of Multidrug therapy for six or twelve months to complete their treatment. In the past 20 years alone, an incredible 16 million people have been cured of the disease. We're working hard to make sure that one day, we'll see an end to leprosy. The key is making sure that as many people as possible get the cure as early as possible.

Why is leprosy still a problem today?

The longer the disease is left untreated, the more severe its effects on a person's body. Leprosy can cause hands and feet to become permanently disabled. At the hospitals we support, surgery to restore movement to affected hands and feet can be carried out, and treatment given to help ulcers heal. But to stop the disease in its tracks before it gets to this stage, early diagnosis and cure are vital.

And it's not just the physical effects. Leprosy is still a feared disease with lots of superstition surrounding it. This means that people affected by leprosy are often rejected by their families and communities. They face devastating prejudice at school, in the workplace, even when wanting to get married.

Has leprosy ever inspired any other Game of Thrones storylines?

Yes. In the later seasons of the original show, we learned about the much-feared disease greyscale, which causes the appearance of the skin to change. Those affected by greyscale were shunned by society and forced to live away from others. This was often the reality for people affected by leprosy in Europe in the Middle Ages, and remains a problem for many of the people we support today.