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Current time:0:00Total duration:6:34

Video transcript

I think when we talk about preventing malaria it's useful to have an idea of what allows malaria to thrive in the first place so for malaria to be a problem in any given community there usually has to be a combination of three things a high human population density a high Anopheles mosquito density and high rates of transmission between the two groups and so if you lower any of these three variables sufficiently malaria essentially disappears and that's kind of what happened in North America and in Europe and in parts of the Middle East and it's really important that we focus on these variables because there's no vaccine for malaria as of now so we just kind of have to take precautions so how can we lower any of these variables well we probably aren't going to lower the population density of humans so I'll leave that one alone but we do have ways to lower the population of mosquitoes in the areas that we live and so one of the ways we can do that is by using insecticides chemicals that kill insects in this case mosquitoes probably the most common insecticide chemical is called a pyrethroid and these work by being sprayed in the house or around your tent or whatever let's say you're camping and when mosquitoes come into contact with these pyrethroids they get paralyzed and then they die it's kind of barbaric but that's the most common insecticide pyrethroid x' that we find in just household insecticide sprays so those will lower the population density for sure and you might have heard of two spray-on bug repellents one called icaridin and one called DEET de et so these are chemicals that you can spray on your clothes or your skin to keep mosquitoes away mosquitoes actually hate the smell of these chemicals we can't really spell it but mosquitoes do so they stay away so that's why these work so well is repellents insect repellents and you've also probably seen those green mosquito coils those are actually made with pyrethroid ziz their main ingredient as well but these coils have more of a mosquito repellent rule rather than a killing role so we've talked about how we can kill mosquitoes we've talked about ways that we can sort of people away from us repel them what else can we do to lower the mosquito density well one of the most effective things we can do is to eliminate their breeding sites and what they do is they breed in standing water or stagnant water cold water that's maybe collecting outside your house in a bucket or in a tire or something like that so we can drain the water or we can add chemicals to kill off or at least reduce the amount of mosquito larvae that can develop in that water so the byproduct would be well hopefully fewer mosquitoes grow up and start buzzing around because they can't develop at the rate they'd like to so these are all things we can do to reduce mosquito density now what can we do to reduce the rates of transmission well we can change our behaviors a little bit because for example we know that mosquitoes are more likely to be out and about in the evenings so we can just be extra careful when we go outside around then and we can wear long sleeve tops and long pants and cover our necks and and so on and this kind of works for two reasons so we physically protect our skin from mosquito bites right we can we can see that but it turns out that mosquitoes are actually attracted to the smells from the oils on our skin so when we cover them up we cover up the smell from our little skin oils as well we can also do non behavioural things too we can modify our house a little bit so we can put screens on our windows and screens on our doors to keep the mosquitoes out and we can sleep in beds that are covered with mosquito proof netting so we're not getting bitten in the night while we're sleeping and you know you can actually get netting material that's been soaked in a repellent or an insecticide and that makes them a lot more effective at preventing mosquito bites and if you just have the net alone but the nets are still really effective the other thing we can do to prevent transmission is to treat people with anti malarial drugs as soon as we know that they're infected because you know if you think about it let's say an infected mosquito bites this guy and infects them well having more infected people around means that uninfected mosquitoes that might come along they can easily draw Plasmodium from this infect person and they can go on and infect another person with it so it's important to get treatment right away if there's a confirmed malaria and now before we finish up there's just one more thing I wanted to touch on and that's malaria prophylaxis medication so if you're traveling to an area of the world where malaria is endemic in other words it's really sort of prevalent there you can take a combination of medications to protect you from the malaria infections while you're there so depending on the drug resistances that exist in the parasites where you're going that would kind of determine what drugs you'd use as prophylaxis so here's a timeline right and here's your trip right in the middle here and so the way that these prophylactic drugs work is that you take them for a period of time before your trip maybe a week or so depending on the drug right and then you take them the whole time you're away let's say you've gone to Southeast Asia for example and then you come home and you continue taking them at home for some period of time could be a week could be a month it kind of depends on the drug you're taking so I know you're probably thinking that these things sound awesome right I mean and they are they are awesome but the downside is that this prophylaxis business only really works for people who don't live in these endemic areas which is kind of ironic so the reason why is well there's a couple of reasons so one they're not super expensive but if you were taking them every single day forever the cost would probably add up to something really really unreasonable - there's side effects right so from long-term use there's side effects that make them a little less attractive to you so they're only really suitable for short-term use and you know let's say the problems 1 & 2 didn't even exist it still would be really difficult to get them transported to every malaria endemic place in the world so I guess availability and transport is a consideration and last using these drugs every single day that would vastly increase the risk that the little malaria parasites would develop a resistance to them and if that happened then the people using them would kind of just be back at square one because the drugs wouldn't work anymore so that's why the focus is on prevention by reducing these two variables here mosquito population density and transmission of the parasites