Could you be a flu super-spreader?

ACCORDING to the UK’S risk register, the number one threat to life isn’t terrorism, it’s pandemic flu.

Unlike seasonal flu that strikes in the winter months, pandemic flu is a worldwide outbreak. It can emerge at any moment and as history has proven, it can be catastrophic.

In new TV show Contagion! The BBC Four Pandemic, mathematician Dr Hannah Fry and emergency medic Dr Javid Abdelmoneim use app technology to ‘infect’ people and see how fast their virtual disease can spread in 24 hours.

Despite advances in medicine, experts admit there’s still a lot they don’t understand about flu infection and contagiousness, which means if a potent strain materialises, it still has the potential to devastate populations. So what do we know?

Every so often a completely new type of flu emerges because humans aren’t the only creatures that get the bug.

“Flu exists in animals such as birds or pigs, and from time to time you’ll get these other animal flus that cross over into humans,” explains Dr Chris Chiu, a clinical senior lecturer and consultant in infectious diseases at Imperial College London.

“The vast majority of people won’t have any immunity against that new strain of flu, so it spreads very quickly across the world.”

The show explores the notion of super-spreaders – where one person is responsible for infecting a lot of others – and what makes some people more contagious than others.

“The concept of super spreaders has been around for over 100 years but mainly in the context of other infections,” explains Dr Chiu. An example is cook Mary Mallon, born in 1869 and nicknamed Typhoid Mary.

She was thought to have infected so many people she was quarantined on an island near New York where she died 23 years later.

“In flu infections it’s not been easy to uncover who super-spreaders are because when flu appears it’s very common, so it’s almost impossible to track down whether a single person has infected two or 100 people,” says Dr Chiu.

“What we do know is people produce different amounts of virus in their nose when infected.” A social super-spreader is someone who comes into contact with a lot of people.

“You could say children are superspreaders because they make a lot of virus as well as the behavioural factors,” says Dr Chiu. “They’re often

Dr Abdelmoneim’s tips to reduce the impact of infectious disease

“Always catch it, bin it, kill it.

Sneeze into your elbow or into a tissue, bin the tissue and then wash your hands with soap or sanitiser. Otherwise, the next person who touches what you have will get a firsthand experience of your nose.”

“If you think you’ve got a lung disease, you’re a pregnant woman, elderly person with a chronic illness, or health care worker, you should be getting vaccinated because you’re helping prevent the spread of virus for the whole population.”

“Ideally self-quarantine yourself.

Two days of solid rest, good sleep, good food, water and warmth are often enough to nip anything in the bud and will actually help you recover more fully, more quickly and stop you spreading it to other people.” snotty and don’t wash their hands enough so that contributes to them being more contagious.”

Researchers also think some people might drive the spread of a pandemic because something in their genes means they become particularly contagious.

In Contagion!, Dr Abdelmoneim gets access to an experiment, conducted by Dr Chiu and funded by the US Department of Defence, which tries to predict who the biological super-spreaders are.

“The study is to understand why some people produce more virus than others but I don’t expect in the near future to be able to definitively say, ‘Yes, this is the kind of person who’s a super-spreader,’ says Dr Chiu.

Researchers think some people might drive the spread of a pandemic because of something in their genes

Dr Chiu’s study sees healthy volunteers given up to two million particles of the 2009 swine flu virus to sniff. One of the volunteers is lecturer Joydeep, 36, who shows few symptoms but makes a lot of virus in his nose. This suggests there’s something about his biology that could make him very infectious – a biological super-spreader.

“I hadn’t heard of this term before. I feel a little guilty about it,” says Joydeep. “But how can I put it, every other human might be a super-spreader but doesn’t know it. All I can do is boost my immune system so I don’t get it and spread it. But it’s important to be aware of what status I am, so I’m careful around people, especially babies.”

Medics are beginning to realise what the immune system does to fight flu infections.

“Some people are probably born with greater resistance to infection and there are certainly some genes which have been identified that are associated with people getting more severe illnesses,” says Dr Chiu. ■■Contagion! The BBC Four Pandemic, will be shown on BBC

Four on Thursday.