Chikungunya? Doesn't sound Italian.

There are a lot of nasty viruses out there, many with strange names that suggest they are mainly problems for remote sections of the rain forest.Since I don't go to remote sections of the rain forest they have been mostly an object of academic interest for me. One of these viruses is an arthopodborne beauty called chikungunya, which has been ably and informatively blogged by my SciBling Tara Smith at Aetiology. But every autumn I head off to a scientific meeting in northern Italy (Emilia Romagna) and now I find that chikungunya has arrived there ahead of me:

A recent outbreak of the debilitating tropical disease known as chikungunya fever in northern Italy apparently marks the mosquito-borne infection's first foothold in Europe, according to European health authorities.

Europe has had scattered cases of chikungunya before, mainly in travelers from parts of Africa and Asia where the disease is established. But the outbreak this summer in Italy's Ravenna province was spread by mosquitoes, according to a report published Sep 6 by Eurosurveillance Weekly. (CIDRAP News)

The virus reaches fairly high levels in the human bloodstream, making person to person transmission via a biting mosquito possible. Sporadic imported cases have been reported in Europe and the US before (i.e., cases contracted elsewhere but with onset in Europe or the US), but the Ravenna outbreak is the first in Europe where the virus has spread to non-travelers. The disease is debilitating but usually self-limiting. Here's is Tara's (excellent) description:

After an incubation period of around a week, the patient suffers from sudden onset of a high fever, chills, and headache. Joint pain can be significant, and may persist for weeks. A rash may be present, and in rare cases (more common in children than adults), a hemorrhagic fever manifestation may occur. (Aetiology)

The vector in Italy is the tiger mosquito, Aedes albopictus, which along with another competent vector Aedes aegypti is also found in the southeaster US. Another arbovirus, West Nile virus (WNV), established a foothold in the US after its appearance in Queens, NY in 1999 and has since spread to almost every state. Whether this will hold true with chikungunya is hard to say. There are two crucial differences. One is that the only known reservoir for chikungunya is humans (although other reservoirs may exist but aren't identified), while for WNV there exists a vast endemic reservoir in many species of birds and possible some mammals. On the other hand, in humans levels of WNV aren't high enough to sustain transmission from person to person via a biting mosquito but they are for chikungunya. Of these two opposing factors, the size of the reservoir is probably more important, but there is a great deal about the dynamics of arbovirus infection we don't understand. The Italian outbreak was a great surprise, and now numbers 166 cases.

The mosquito season I hope will be over by the time I get there but I've been there at the same time of year when it has been unseasonably warm, so I am not entirely confident. Self limited or not, it sounds unpleasant, and in some cases aches and pains can last for months. Sorry, but that's not for me.

A century ago there was still a fair among of mosquito borne disease in the US, especially malaria and yellowfever. Now we have the encephalitidies (WNV, St. Louis Encephalitis, Easter Equine Encephalitis and a few more), the possibility of dengue and now chikungunya.

Globalization at its finest.