#24 – Travel Viruses: Scandinavia, Mosquitoes and Sindbis Virus

00:00:06: How often does the disease occur?

00:00:08: It's relatively rare.

00:00:10: In Finland, there are about a hundred cases per year on average but larger outbreaks occur approximately every seven years.

00:00:33: Virological with Florian Kramer.

00:00:46: Welcome to this episode of ViroLogical.

00:00:48: This was recorded on the thirteenth of July of twenty-twenty six in Vienna And we're going to continue our summer series of viruses that you can get when your on vacation from Moschitos.

00:01:06: Last time, I talked about Toscana virus in Italy and there are some people who don't like to go south because it's hot... ...and they have weird diseases so they could go north.

00:01:17: Scandinavia for example is a nice destination specifically if you like hiking fishing etc.

00:01:24: And so today we're going to talk about a virus infection that you can acquire if you go north, to Scandinavia in summer.

00:01:35: We are gonna be talking about disease called Pogosta disease or Oculpa disease or Carillian fever.

00:01:42: it's basically all the same different names and this is caused by Synthbis Virus.

00:01:50: Now what is SynthBis Virus?

00:01:53: Synth Bis Virus is an Alpha Virus relatively unknown, mostly because there's not that many cases and many of the cases that occur are mild.

00:02:04: But it is a virus which actually related to chikungunia virus.

00:02:07: That another alpha-virus causes lot of issues in tropical and sub-tropical countries but Zinbis virus has different spread.

00:02:16: It's pretty interesting from molecular biology perspective.

00:02:19: its close to Chikungunya In terms of disease it's kind-of similar to outpoint deadout.

00:02:27: Okay, so this is an alpha virus.

00:02:29: Alpha viruses have a RNA genome, singly stranded RNA genome with positive polarization.

00:02:36: The virus particles are sixty five to seventy nanometers in diameter.

00:02:42: They're very regular.

00:02:43: they really beautiful Really nice shape and you can resolve or look at the structure of them in an electron microscope.

00:02:54: and basically, this structure on a atomic level can be resolved in cryo-electron microscopy because they are so regular.

00:03:07: We have RNA inside then we have a capsid and then a lipid membrane And then we got glycoprotein.

00:03:18: That's very regularly organized.

00:03:21: This glycoprotein or spike protein actually is divided into three subunits E-one, E-two and D-three.

00:03:29: And yeah that's it!

00:03:30: It's a relatively simple particle like all alpha viruses.

00:03:35: Simplest virus also comes in different genotypes.

00:03:38: I think there are about six different genotypes i'm not hundred percent clear on And it seems that only one genotype, the Genotype G-one is associated with human disease.

00:03:50: These viruses are transmitted by cool ex mosquitos including Cool Ex Bipiens which is a mosquito that's super common in temperate climates globally and areas where these mosquitoes exist include basically lot of European countries.

00:04:07: It also very common mosquito in Central Europe, Eastern Europe, Northern Europe and so on.

00:04:14: So this mosquito doesn't need to have hot tropical climate.

00:04:18: it can actually deal with relatively cold weather.

00:04:21: So yeah these viruses are mostly transmitted by cool ex mosquitos but can also be transmitted by Coolisetta mosquitoes potentially some other mosquito species.

00:04:33: Historically the virus was discovered and isolated first in a pond in Sintpis and that's where the name comes from.

00:04:42: Sintbis is a village, I believe about thirty kilometers north of Cairo in Egypt.

00:04:48: this was already in nineteen fifty two.

00:04:50: then there were reports for first human cases mostly in central and southern Africa.

00:04:56: in Uganda cases were reported in nineteen sixty one In South Africa in nineteen six three And then in nineteen sixties seven.

00:05:05: they were most first evidence first in Sweden and then later, in nineteen seventy-four also in Finland.

00:05:17: And the cases in Finland were reported In Ilomantse.

00:05:22: that's a village That has a second name.

00:05:25: The second is Pogosta and thats why its called Pogosto disease.

00:05:28: Then it was in Sweden.

00:05:30: It´s called Akalbo disease.

00:05:32: I think Thats also named after settlement Karelia is a region on the border between Finland and Russia.

00:05:44: It was basically Finnish, but I think during the Winter War Finland lost part of it to Russia And that's that region on board.

00:05:56: You have cases there too.

00:05:57: That why its called Karelian fever.

00:06:00: But the virus is prevalent in many areas.

00:06:04: In Africa, Asia and Europe because these mosquitoes are very widespread And... ...in Europe.

00:06:12: of course you can find the virus in Scandinavia but it has also been detected in Spain for example or in southern Germany relatively recently.

00:06:23: So its widespread which makes sense Because it's It can be everywhere where this mosquitos aren't there widespread.

00:06:31: The interesting thing you don't get disease in all of these areas and that might have to do with the different genotypes that are circulating.

00:06:39: The animal reservoirs are gully form, basary form birds including grouse.

00:06:46: Grouse is one of the main reservoirs it seems And birds can also spread the virus.

00:06:51: That may be another explanation for the widespread of synthpysvirus.

00:06:56: And then you get transmission from birds to humans through insects, through these mosquitoes.

00:07:04: This usually happens in August or September so late summer basically early fall.

00:07:12: and the interesting part is that areas where there are a lot of this virus endemic areas zero prevalence in population can be relatively high So three percent and that suggests there's a lot of asymptomatic infections.

00:07:30: And in fact, studies have looked into this and it seems the rate of asymptomatic to symptomatic infection is about twenty-one to forty-one.

00:07:41: If you get infected and you get symptomatic that usually happens after an incubation time three or four days then you'll get fever muscle pain often a rash, which is similar to the rash that you can get when you have chikungunia.

00:07:58: I think it's little bit less pronounced but kind of looks similar and in relatively rare cases encephalitis cannot occur And thats of course severe disease then.

00:08:09: But Thats not their only issue The other issues.

00:08:12: this happens again with many alpha viruses including chikngunia.

00:08:18: You can get a trial germ And that can last for quite some time.

00:08:22: Usually you have the ankles, the wrists and fingers... ...and this actually lasts for many months I think six to eight month on average but it also lasts four years again.

00:08:34: This is very similar to chikungunya.

00:08:36: You could even say that this disease is kind of the Chikungunya in North Even though we have it in Africa or Asia as well But its' very well known as a set from Scandinavia.

00:08:48: How often does the disease occur?

00:08:51: It's relatively rare.

00:08:53: In Finland there are about a hundred cases per year on average, but larger outbreaks occur approximately every seven years and The last large outbreak in Finland was in twenty-twenty one with an incidence of about forty cases per hundred thousand people.

00:09:12: That is not so little.

00:09:14: What can you do if we get infected?

00:09:16: Basically not much, just hope that you don't get this atralgia.

00:09:21: The acute phase ends relatively soon itself resolving.

00:09:25: so it's not bad.

00:09:26: as long there is no encephalitis.

00:09:28: but of course the problem would be to have a long-term atralgia.

00:09:34: But unfortunately nothing really happens in terms fighting the virus infection, of course you can try to take anti-inflammatory medication.

00:09:43: If you get this inflammation in your joints, this atralgia but there are no antiviruses that would directly act on the virus and that will counteract the infection.

00:09:54: There's also no vaccines.

00:09:56: again This is a relatively rare disease so it doesn't make sense to make vaccines specifically not from an economic perspective And so the only way to prevent disease is basically use mosquito repellent long pants when you go hiking, long sleeves and make sure that don't get bitten.

00:10:16: Alright!

00:10:16: So this was second episode of our summer series where we are talking about weird viruses that gets transmitted by mosquitoes when your on vacation.

00:10:28: With that, as always if you have any questions concerns comments feel free to write an email to virological at podcastwerkstatt.com and If you like this podcast You can support us on steady.

00:10:41: thanks for listening in And until next time!