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Skip to 0 minutes and 12 secondsSo what happens when you get infected by a mosquito when it bites you? The virus obviously enters the body and

Skip to 0 minutes and 23 secondsreplicates, but for some unknown reason, despite it doing that only a small proportion, roughly one fifth or 20% then go on to develop illness and the illness can vary in its severity to becoming a very mild illness or a fever and feeling quite unwell. Fortunately, of all the flaviviruses, this probably causes the least serious types of symptoms. So most people who have it will have a minor, minor illness. What are the symptoms? Well, the symptoms are varied, but one of the commonest ones are joint pain and skin rash.

Skip to 1 minute and 10 secondsSkin rash is very atypical and unusual in that it tends to be an itchy rash and it tends to be of what we called maculopapular which means it's a blotchy red abnormality on the skin. Most of the other viruses tend to cause a rash which looks like there's some bleeding or some some red cells in the skin and that's very different to the Zika rash. You get some joint pains, you feel unwell, typically people say flu like; you don't have any symptoms of nose running or anything like that but you just feel under the weather. And that lasts up to five days, normally less, and then you get better completely, so overall a benign, mild illness. And only in 20%.

Skip to 2 minutes and 1 secondWith Zika then it knocked me down for about two weeks or so. What I mean is I wasn't in bed for all that time, I was just in bed for about half a day, but the rest of the time I wasn't myself, I was not thinking sharply, I felt tired, weak. It started one night; I was kind of feverish? Next day that passed but I had for a few days kind of shooting pains all over my trunk, it was a bit like shingles but much much milder and then after that I had a rash on my arms and legs. Which wasn't painful or itchy or anything but that lasted for a few days.

Skip to 2 minutes and 41 secondsAnd then after that I had a kind of aching in my hands. And my wife's a medic and that's when she got a bit worried because she thought maybe it was the onset of neurological complications but that passed after about a day and then I was just, you know, still a bit weaker and and tired for a few days while while I recovered. I did have dengue before as well and it was a bit like that but much much milder. So after a few days my wife thought "well, maybe that's Zika", and she got me tested at a lab and it came back positive obviously but I didn't go to a clinic.

Skip to 3 minutes and 20 secondsBecause you know there is no specific treatment, I wasn't feeling that bad, so they didn't really see much, you know, much upside to to doing that. So what are the complications of having the virus? I've talked about the minor symptoms but there are some more serious ones including that which occurs in during pregnancy where the virus invades the developing fetus and causes, particularly, brain damage but it also seems to be able to set off the Guillain-Barré syndrome. Now, Guillain-Barré syndrome is a condition where you have nerve damage.

Skip to 3 minutes and 53 secondsIt's called polyneuropathy because it affects many nerves; it affects the sensory and the motor nerves and is ascending which means it spreads from usually from the peripheral parts of the body up to the main parts of the body. And as a consequence of that you become gradually more paralyzed and losing sensation and the worst in the small number of people is that it actually paralyzes their respiratory function which means they can't breathe and they then need artificial ventilation to keep them alive. It's not a permanent condition and it returns to normal, the nerves start functioning after some while you get back sensation and motor function.

Skip to 4 minutes and 41 secondsWe don't know why it comes, it actually occurs in a number of other infectious diseases so it's not unique to Zika, but occurs in fact after having vaccines as well. But it's rare and how frequent it is with Zika is as yet unclear but it seems to be notable that it's occurring and it's probably one of the more serious consequences of the infection and on the same sort of concerns I expressed about it as the effects on pregnancy. What about the other 80%? Well they're interesting because of course they are the people who are carrying the virus, are infectious to other mosquitoes and can spread it on. And they don't know it. And they're known as a reservoir.

Skip to 5 minutes and 31 secondsAnd it's not only humans who are reservoirs of course, it's other animals, so there's a wide range of animals who are known to carry the virus and probably that's why it keeps being sustained even if no humans have got it. If it's in other small mammals, or primates and infecting mosquitoes and these mosquitoes are very widespread and will bite all these creatures, they are able to spread it on.

Who gets ill and how are we affected?

What are the symptoms of Zika? How ill does it make us? In the video, Dr Ron Behrens and Dr Neal Alexander explain how an individual might become ill after being infected with Zika virus, the approximate numbers who tend to do so, and some of the tragic and well-publicised complications that can follow.

Most people infected with Zika experience no symptoms at all, and for those who do they are often mild. Dr Alexander, who has had Zika, highlights some of the specific ways he felt when he became unwell. Have you or has anyone you know been ill with Zika? If so, how would you describe the symptoms? Did you visit a doctor or other healthcare provider? Remember not to share any private or personal details in the comments.

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Preventing the Zika Virus: Understanding and Controlling the Aedes Mosquito

London School of Hygiene & Tropical Medicine

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