Tropical viruses are right on our doorstep



Dr. Jos: "Ebola? That's just the tip of the iceberg."

You've just asked the waiter to remove the lucky bamboo plant from our table. Why?
Dr. Jos: Because this filth is the cause of the rise of the Asian tiger mosquito in Europe. We often see it in Belgium, but it's really settled itself in The Netherlands. No wonder, of course. Lucky bamboo plants are dirt cheap, ugly as hell and need no care. The ideal indoor plant for the average Dutchman! That these cute bamboo plants are importing tiger mosquitos, is something Kees and Sjaan obviously haven't thought of.

Why is the tiger mosquito dangerous?
Dr. Jos: Because it can transfer dengue fever, a dangerous flavi-virus. It's very difficult to protect yourself from it, because the tiger mosquito also bites during the daytime. In origin it's a tropical disease, but by now, even the south of France and Italy have seen outbreaks of dengue. So it's just a matter of time before it's our turn.

Dr. Jos: Yep. (pays for two large trappist ales) It's one of four large classes of viruses ready to conquer Europe. Okay, when I say: name a deadly tropical virus, what springs to mind?

Dr. Jos: (drinks and nods) The answer I expected. Ebola is notorious because it's transferrable from man to man and it causes one of the most deadly haemorrhagic fevers known. However, most viruses need a vector: a mosquito, fly or tick. These are called arbo-viruses. There's also zoonoses, viral diseases you'll catch from contact with rodents. Believe me, all this is closer than you think.

Ebola as well?
Dr. Jos: Yes and no. Ebola is a filo-virus, another one of the four virus classes I was talking about. Filo-viruses were only discovered in 1967, in the Behring-lab in Marburg, a city in what was then Eastern Germany. Thirty-seven people got seriously ill from contact with contaminated meerkats in Uganda. The Marburg-virus was the very first filo-virus. Ebola is its even more horrible little brother.

What a family!
Dr. Jos: Ain't it? And this is just the tip of the iceberg. The flavi-viruses are more important. You'll find them just about everywhere, not only in Africa. Dengue is an example, and so is the very well-known yellow fever. In idyllic Kerala in India, you have a good chance to catch Kyasanur Forest Disease. You'd rather travel on the Trans-Siberian railway? Brace yourself for the Omsk-virus, imported by muskrats. North-America? The Powassan-virus is on the prowl. The Middle-East? No good either, because the Alkhumra-virus is coming go get you.

Hardly on my doorstep.
Dr. Jos: On the contrary. Flavi-viruses are on your doorstep. After a nice walk in Austria or Central Europe, you could die of encephalitis in your mountain refuge, thanks to the Tick-borne Encephalitis Virus, or the 'Frühsommervirus', as the Austrians like to call it. Would you rather go on a walking holiday in green, cool England? Sheep will give you Louping Ill Virus. There's simply no escape!

Stop it, I feel like I'm catching a fever already.
Dr. Jos: Stop? (laughs) Forget it! I haven't even mentioned the arena-viruses yet. The Lassa-virus in West-Africa, for starters. During one of the last major outbreaks of Ebola in West-Africa, they first thought it was Lassa. They underestimated the problem, and it escalated. In more civilized South-Africa, you'll encounter the Lujo-virus. Let's travel the world following the arena-viruses, shall we? Junin in Argentina, Machupo in Bolivia, Guanarito in Venezuela, Sabia in Brazil... Do you want me to continue? There's more than twenty of 'em, but luckily these haven't yet been detected in Europe.

Just as well.
Dr. Jos: (looks sceptical) For now. I wish I could say the same about the bunya-viruses. These are found everywhere. A virus that's rising fast in the hit parade of dangerous motherfuckers, is Crimean Congo Haemorrhagic Fever. A really dangerous one, because it doesn't need a vector. You can get this fever by close contact with a contaminated person. In Turkey, Crimean Congo already is responsible for about a thousand deaths a year.

Turkey? That's frighteningly close.
Dr. Jos: Even closer, and also belonging to the bunya-viruses, are the hanta-viruses, spread by voles. In our Ardennes, for example. If you're contaminated, you'll get acute kidney problems. Unless your hanta-virus is from the New World, then you'll get a mean case of pneumonia.

Is the rise of these viruses related to global warming?
Dr. Jos: (shakes his head) Absolutely not. Global trade is the culprit. Most of the insects and rodents transferring deadly viruses haven't arrived in Belgium yet, but they're on their way. In a container of green beans from Africa. In a container of roses from South-America. Ready to escape in the port of Antwerp and stay. It's just a matter of time.

What can we do in the mean time?
Dr. Jos: Drink another trappist ale. (raises a hand) Waiter! Two more trappists please, and there's a big tip for you if you remove these filthy lucky bamboos from all the other tables as well!


Dr. Jos recommends these relevant papers:
Kiran e.a., Kyasanur Forest disease outbreak and vaccination strategy, Shimoga District,
India, 2013-2014, Emerg-Infect-Dis., jan. 2015
Dash e.a., Emerging and re-emerging arboviral diseases in Southeast Asia, J-Vector-Borne-Dis., apr. 2013
Lasala e.a., Tick-borne flaviviruses, Clin-Lab-Med., mrt. 2010
Lin e.a., Analysis of the complete genome of the tick-borne flavivirus Omsk hemorrhagic
fever virus, Virology., aug. 2003
LeDuc, Epidemiology of hemorrhagic fever viruses, Rev-Infect-Dis., mei 1989
Mertens e.a., The impact of Crimean-Congo hemorrhagic fever virus on public health, Antiviral-Res., mei 2013
Hubálek e.a., Tick-borne viruses in Europe, Parasitol-Res., jul. 2012
Ergunay e.a., Current status of human arboviral diseases in Turkey., Vector-Borne-Zoonotic Dis., jun. 2011
Gould e.a., Potential arbovirus emergence and implications for the United Kingdom, Emerg-Infect-Dis., apr. 2006
Jeffries e.a., Louping ill virus: an endemic tick-borne disease of Great Britain, J-Gen-Virol., mei 2014
Raval e.a., Powassan virus infection: case series and literature review from a single
institution, BMC-Res-Notes., okt. 2012
Růžek e.a., Omsk haemorrhagic fever, Lancet., dec. 2010
Patterson e.a., Epidemiology and pathogenesis of Bolivian hemorrhagic fever, Curr-Opin-Virol., apr. 2014
Scholte e.a., Accidental importation of the mosquito Aedes albopictus into the Netherlands: a
survey of mosquito distribution and the presence of dengue virus, Med-Vet-Entomol., dec. 2008
Versteirt e.a., Introduction and establishment of the exotic mosquito species Aedes japonicus
japonicus (Diptera: Culicidae) in Belgium, J-Med-Entomol., nov. 2009