The Noro Show

The Winter Olympics are finishing in Sochi, Russia this week. But it's not just the athletes who've spent the last four years training for the event. Engineers and designers have also been working to reduce times and grab golds on the slopes. In fact, when asked about her gold medal in the Women's Snowboard Cross Eva Samkova from the Czech Republic  said "It's just physics, that's all,". To find out more, here's your Quick Fire Science with Kate Lamble and Harriet Johnson.

·         - Friction, air resistance, and gravity are the main forces that track and equipment designers working on the Winter Olympics need to consider when they are trying to make times as quick as possible.  

·        - In order to reduce friction, skis and snowboards are waxed before use. A professional wax technician has around 500 different products to choose from and selects the right wax for the snow conditions.

·        - When the snow is wet, a water repellent additive called fluoro, is increased in the wax, but this can create more friction if too much is added. Antistatic waxes can also be used to reduce electrostatic charges which can build up over long races.

·        - Snow type has been a problem for some races in Sochi with snowboarders complaining of soft snow in the halfpipe. By spraying water and salt onto tracks organisers hoped to melt this soft top layer before allowing it to freeze again into harder ice.

·        - Rather than snow, ski jumping tracks are actually made from ceramic. When moistened with water, these have the same friction characteristics as snow but allow the sport to be conducted all year round in almost identical conditions.

·        - To combat air resistance special skin tight suits are worn in a number of sports. However Team USA have just dropped their newly designed speed skating outfits following poor performances.

·        - There have been some suggestions that vents on the backs of the suits, designed to dump excess air might instead be causing a slight drag effect. While this hasn't been proven the team chose to swap the suits as athletes were concerned about the possibility of their performance being affected.

·        - In other sports, equipment is also important to help athletes perform at their best. In luge, weight vests can be worn by lighter competitors to minimise the advantage carried by their heavier peers.

·        - In curling, players wear one rubber soled shoe to allow them to push off from the ice and one teflon soled shoe. The teflon has a reduced friction coefficient and so allows them to glide across the ice.

·        - Commercial companies also help in designing equipment. Great Britain's gold medallist in the women's skeleton had her sled designed by motorsport company McLaren. The designers used computer simulation to make sure it could be adapted to suit a range of different tracks.

A way to grow blood platelets, a critical ingredient in the cogulation system, has been announced by scientists in Japan.

When you cut yourself, tiny little blood cell fragments called platelets rush to the rescue, helping the blood to clot and the wound to heal. They're a vital treatment for people hurt in accidents, or those with certain blood diseases, but they can only be gathered from blood donations. And, as any doctor will tell you, there are never enough donations, especially because platelets have to be kept at room temperature and have a very short shelf-life.

But this could be about to change, thanks to an important new paper from Dr Koji Eto and his team in Japan, published in the journal Cell Stem Cell. In it, the researchers describe a new way to create platelets from stem cells grown in the lab, potentially reducing the need for donated platelets in the future.

The researchers used a recently developed technique that we've heard a lot about lately - so-called induced pluripotent stem cells, or IPS cells. This is a way of turning adult cells into stem cells by adding a handful of protein factors - a discovery that won Japanese scientist Shinya Yamanaka a Nobel Prize in 2012.

Eto's team treated IPS cells with a cocktail of genes that converted them into a type of cell called a megakaryocyte - a large precursor cell that produces platelets. And the platelets the converted cells made had similar clotting capabilities to platelets from donated blood.

Scientists have previously tried to create platelets from reprogrammed stem cells but the yield has been very low, whereas this new technique produces large quantities. Furthermore, the megakaryocyte precursors can be safely frozen, and could potentially be grown on a large scale, which might mean platelets on tap on the future.

Norovirus, or the winter vomiting bug as most people call it is the most common stomach bug in the UK, affecting up to 1 million people a year and it's particularly prevalent at the moment.

Chris Smith caught up with Ian Goodfellow, from the Department of Pathology at the University of Cambridge, to find out more about what we know about the virus.

Ian -   Noroviruses are small highly infectious viruses that cause gastroenteritis.  They're typically referred to in the public press as the causative agent of a winter vomiting disease.  But outbreaks occur all year round.  The reason they're referred to as winter vomiting disease is simply because of the peak incidence appears to occur in and around the winter months.

Chris -   Why is that?

Ian -   It's probable that they tend to survive longer in the environment in the cold and wet.  But also, people tend to spend a bit more time together during the winter.  The reality is, we still don't know.  It's one of the important questions that need to be addressed for noroviruses.

Chris -    When you say the agent lurks in the environment, give us a sort of a snapshot view.  What do these viruses look like and how do they get into the environment?

Ian -   So, these are tiny, tiny little viruses, one of the smallest viruses around.  The virus culture, the shell is made up entirely of protein.  So, this makes them particularly resistant to inactivation by detergents and things like that.  They get into the environment primarily through the vomiting or the diarrhoea episodes.  People would have to get into the sewer systems and they contaminate the water courses.  They often will also contaminate shell fish and people will get norovirus infection from eating contaminated uncooked shell fish.

Chris -   When you say that it can stay in the environment, if a person is symptomatic in an area, how long will that area retain virus that's capable of infecting someone?

Ian -   Probably in the region between 7 to 10 days.  If not, longer.  If it's untreated, it is probably going to remain enough infectious material that infects somebody for at least a week.  This is partly because you need to be exposed.  Very few particles are required to become infected so less than 20 particles are thought to be enough to cause an infection.

Chris -   When a person is symptomatic, to put that into perspective, how much virus are they shedding?

Ian -   An individual would normally shed somewhere in the region of a million or more virus particles per millilitre of faeces or vomit, and you need only 20 to infect an individual.  So, each infected individual can infect many million others.

Chris -   Wow!  It's amazing to think there's millions of infectious doses in every single person, isn't it?

Ian -   Absolutely.

Chris -   So, when I ingest norovirus, I've got to pick it up from the environment.  It presumably gets either onto the food I'm eating onto my fingers and gets into my mouth and I then swallow the particles.  What happens next?

Ian; -   That's a very good question.  In fact, we don't really know much about the life cycle of noroviruses particularly in the gut.  So for example, we know it grows in the intestine, but the reality is, we don't know precisely what cells in the intestine it infects.  What we do know is it basically mimics the body's response to eating something that's poisonous.  It stimulates this response known as the emetic response where effectively, your body will eject all the contents of the stomach and this is the vomiting episodes that you get.  And then you will flood the intestine with fluid to try and wash out any poison.  We think what the viruses do in stimulating this process either directly or indirectly by interacting with certain cells of your nervous system.

Chris -   What about other animals because people often ask me, "Can my dog give me diarrhoea?"?  Do we exchange these infections with animals or is this purely a human infection?

Ian -   This is a very good question.  Norovirus has been identified in a whole range of animals and there appears to be very specific noroviruses for cats, for dogs, for cows, for pigs for example.  But there is limited evidence now that human norovirus can be found in the pig population.  Whether or not there's this [genetic] transfer from pigs to humans is not entirely known.  And in fact, there's limited data as well to say that in some cases, human noroviruses can be found in dogs and this is something that we're working on my lab to try and see if this is a common occurrence.  At present, we think that human noroviruses are not a [genetic] disease so they primarily infect humans.

Chris -   When I catch it, am I immune to it almost immediately that I've caught it.  Is that why the symptoms go away because the symptoms do go away pretty quickly?  Within 48 hours, you're feeling all right again usually, aren't you?

Ian -   That's right, but it's likely you don't generate a very good immune response and we think one of the reasons these are such effective pathogens is simply because you don't generate long lasting antibody responses to this virus.  It's more a process known as you're innate in your response.  It clears the virus so the virus is not there for very long.  Therefore, we don't generate very good antibodies.  So, we can be re-infected probably once every year by the same virus.

Chris -   Got you.  Are there also lots of other strains circulating?  So, although I've had one type previously, I may in fact pickup another next week to which I have no immunity and I can go down with this again?

Ian -   Yes, again so one of the features of these viruses is that every time they multiply or copy the genetic material, they make mistakes.  This means the virus can evolve very rapidly.  Typically, in any one year, you'll find that there are at least one dominant strain or isolate of norovirus, but that will evolve.  There'll always be minor species within that.  In fact, within any individual who's infected, whilst maybe one strain of virus, each individual virus particle will contain a slightly different sequence.  This gives the virus the ability to evolve away from any immune response.

Chris -   Does that frustrate efforts to make a vaccine then?

Ian -   This causes a lot of problems to the vaccine production.  However, there's very encouraging data coming from a company known as Takeda.  Their data suggests that you can protect from infection if you immunise individuals with the same type of norovirus strain and that will protect primarily from symptoms.  So, less than 50% of individuals who develop symptoms and this can prevent spread.  It's likely though if norovirus vaccine becomes viable.  It's likely it would need to be changed every year, very similar to the influenza virus vaccine.  However, us and a number of labs around the world are trying to develop new vaccines that give cross protective immunity.  Probably in the next 5 to 10 years, they'd be looking at larger scale trials of human norovirus vaccines.

Chris -   Thank you very much to Ian Goodfellow, from the Department of Pathology at the University of Cambridge.

If someone you know has norovirus how can you protect yourself? Infection control nurse Rachel Thaxter joins Chris Smith in the studio to show us how to wash our hands properly..

Rachel -   This is a gadget we use in hospitals to teach student nurses and medical students how to wash their hands.  We use a cream that's got a UV impregnated particle in it and we asked the staff to put this cream onto their hands and rub it in like hand cream all over the surface of their hands and their nails.  We then asked them to go and wash their hands and see how successful they are at actually washing this cream off.

Chris -   Because if they were potentially infectious for norovirus or had contacted a surface with norovirus, hands are presumably the main route via which infections spread.

Rachel -   Yes, hands are key in all infections really.  So, good hand washing, good hand hygiene at all times is what we recommend.

Chris -   Well, I found you a victim.  Harriet Johnson who's here with us from the Genetic Society.  How's your hand washing, up to spec?

Harriet -   They look pretty clean.  They look alright.

Chris -   What do you want her to do, Rachel?

Rachel -   I'm just going to put some cream onto Harriet's hands.  So, just a nice splodge of that.  all of your hands like a hand cream, your nails, your wrists, your thumbs.

Chris -   So, this is called glow and tell.  So, this is just a dye which will glow under UV.  The idea being that you're going to send her off to wash her hands.

Rachel -   That's correct, yeah.

Chris -   And if she misses bits, we'll know.

Rachel -   We will, yeah.  It's not actually highlighting the bugs on the skin.  It's just like a cream which will then dry and wash off to mimic the possibility we have all these bugs on our hand and Ian said there's thousands of them.  So, off you go and wash your hands.

Chris -   Okay, Harriet so, off you go and wash your hands now as you would do normally.  So, just how you would judge your hands to be clean after washing say, you've been to the loo or something.  I presume you wash your hands after.

Harriet -   Yep, always, never  a walker.

Chris -   We'll see you in a minute.  So Rachel, what some practical tips can you give people if someone goes down with D&V in their house?  What's the best way of someone not spreading it around the family?

Rachel -   Isolate yourself.  So, stay in your room. If you've got the luxury having many toilets in your house then try and allocate a toilet to the sick individual with their own hand washing basin.  If you haven't got that luxury, then making sure that the affected person has their own towels and flannels.  There's no sharing of those kind of items.  Keep yourself hydrated.  We don't really want the sick person preparing meals for the family.  Obviously, if that's vital then scrupulous hand hygiene will be needed.  Keep yourself segregated until your well.  As we said, that normally is within 1 to 2 days and then you can start getting things back to normal within your lifestyle.  And that's why when you come into the hospital, we ask you not to come if you've been unwell and not to come if you've been unwell in the last 2 days.  We don't want the community bringing bugs into the hospital and then giving it to our vulnerable patients.  At the moment, we've only got I think 2 or 3 cases in the hospital Chris.  So, we know it's out in the community.  I mean, we want to keep it that way.

Chris -   What about the cleanup measure because we hear a lot about people saying, "I use alcohol hand rubs and I wipe the taps" and that kind of thing?  What practical advice can you give people for a.) their own hand hygiene to make sure that they don't either transmit it or pick it up and b.) cleaning surfaces where someone has been unwell?

Rachel -   Alcohol gels are really good in hospital when we've had social contact with patients and we're not dealing with patients who are unwell or dealing with their body fluids.  Really, in the home, I only use hand gels if I'm out on a picnic or somewhere where I can't actually wash my hands properly.  I don't use it as a substitute to washing my hands.  So in the household, good old fashioned soap and water is the best thing.

Chris -   Because I did read that those alcohol gels are actually no use against norovirus because like Ian was saying at the beginning, it's a particle that doesn't get broken down by alcohol.

Rachel -   That's correct.  So again, we're ask you not to use it in hospitals when we have problems and say, not use them at home as a hand hygiene product.

Chris -   Mark has got in touch and says, "How long does it take for symptoms of this to come on?  I'm surprised I've not caught it from spending time on underground trains that are packed with people from around the world."

Rachel -   It's pretty rapid I think as we all know if we've looked at people with it.  People can feel fine at 10:00 o'clock in the morning and then half past 11:00, actually vomiting and feeling really unwell.  They tend to look a bit grey and ashen.  So, it's a bit of a giveaway then.  But as I say, normally, the patient can be quite well and then suddenly, they'll just be unwell.  So, you may well have to clean up at home.  And again, good cleaning, you can use sort of bleach based products.  They're good for cleaning body fluids.  If your clothing become soiled or bed sheets then wash them on a hot wash and again, do them separate to the rest of the family.

Chris -   Our hand washing victim Harriet is back.  Did you do a good job?

Harriet -   Yeah, I did what I regularly do.

Chris -   You would judge your hands to be clean.  Rachel, what's the verdict?

Rachel -   Let's pop your hands into my UV box, Harriet.  Okay, so we can see actually the areas that Harriet hasn't washed quite as well as she thought she had, are glowing nice and bluey white under my UV box.

Chris -   All the backs of her hands.

Rachel -   The backs of her hands.

Chris -   Where her watch is...

Rachel -   Yeah, you can see where her watch is.  Which is why we don't wear watches in the hospital or bracelets because we need people to be bare below the elbows, so they can wash their hands properly.

Chris -   Too much bling, Harriet.

Rachel -   There's quite a lot as well around your finger nails there.  So again, these areas, you'll find it difficult to wash and also, Harriet is showing quite nicely that her thumb on her less dominant hand is pretty well covered whereas her other hand is quite good.  So, if your right handed, you washed your left hand really well, but if your - obviously, your dominant hand is the one you're going to be doing all the things with and that's the area unfortunately we don't wash as well.  So, it's quite a big difference between Harriet's right and left thumb and as Chris said, that she got loads in the back of your hands, Harriet there.  You've done quite well in the front of your hands.  It's really just showing up all the nooks and crannies where bugs can be hiding.  And also, if your skin is quite dry like it is in the winter then again, these areas where bugs can hide quite happily.

Chris -   I suppose it's worth emphasising as Ian Goodfellow pointed out the infectious dose for norovirus is 20 particles and each person is shedding millions and millions.  Enough in fact to infect the entire world from one infectious person.  And any patch of Harriet's skin could have easily an infectious dose of noro.

Rachel -   It could, yeah.  What do you think, Harriet?

Chris -   What do you think about it?  Are you shocked?

Harriet -   Yeah, yeah I'm filthy.

Chris -   We know that, but I mean, were you quiet surprised at the finding?

Harriet -   Yeah, I mean, there were ones that I was expecting like the back of the hands.  I always think people don't pay attention to that, but I did find the difference between the two hands themselves interesting, as one of my hands is dirtier than the other one.  So, I'll change the way I shake hands next time.

Chris -   Rachel, one quick question from Jonathan Bowman who got in touch and has said on Facebook that, is it true that it's virtually impossible to eradicate norovirus from surfaces without resorting to industrial strength bleaches, presumably and hopefully not?

Rachel -   I mean again, good soap and water, so good basic cleaning you have in your house.  I'm not sure whether Lydia knows any more than that, but generally, infection control is all about good hygiene and common sense.  So, what do you think Lydia?  Can you help me out there?

Lydia -   Yeah, actually, in studies where they were cleaning wards and then swabbing afterwards to identify whether or not they cleaned well, they actually did show that a bleach, type of 10% bleach solution plus additional soap and water washing was what was required.  So, my guess is it's repeated washing if you can't use a 10% bleach solution.

Chris -   Thank you to both of you.  Kat...

Rachael - Well, you can't hydrogen peroxide onto your skin of course, but we do use that in a vapour form we're cleaning our wards. We do deep clean areas that have norovirus outbreaks or side rooms that have had patients who've been infected in them. So, we do quite robust cleaning at Addenbrookes using the HPV process. So, you can't get a spot into your skin. They're highly toxic in higher concentrations that the vapour forms are very small amount of agent that's there. It is very effective at cleaning our environment. Some of the gels do claim to be effective against flu virus and things like that, but as we've said really, although they say they are, it is always the best gold standard to wash your hands, if you've got that facility, so gels are so useful in a hospital for social interaction with patients and really useful if you're in a situation where there isn't hand washing facilities such as on a picnic or family holidays and things like that. But we generally say, although they say on a label, "We will kill flu", "We will kill viruses", we generally say, we shouldn't rely on that.

Infection-control nurse Rachel Thaxter answered this question...

Rachel - Well, at least for 48 hours.

Chris - I don't think he's implying he's going to cook dinner while he's having vomiting.

Rachel - Obviously not.

Chris - How long should people not come around your house for?

Rachel - If you're really good at cleaning, perhaps a week, clean your house a couple of times, your bathroom is the key area, the kitchen, a week.

Chris - So, defer that dinner party for a week Mark and you'll probably be alright!