An unnamed chikungunya-infected tourist from south India is responsible for the spread of the tropical disease in a small north Italian town, according to health officials who now anticipate that the disease could soon surface in Britain and turn into an epidemic across Europe.
In August, Italy's ministry of health confirmed at least 200 cases of chikungunya in the Ravenna region. British travellers to the region have been told to protect themselves against mosquito bites.
The European Centre for Disease Control has advised pregnant women and those with serious illnesses to avoid the region.
According to researchers and health officials, the man from south India was the possible source of the virus, which started spreading in July in the hamlet of Castiglione in the Ravenna province. The man was bit by mosquitoes while he was staying with relatives there.
The virus reportedly spread to four other people in the house where he was staying. The virus soon spread from there. Regional health official believe that the virus had been contained and that no travel restrictions had been imposed on residents of the region.
Health officials believe that this was the first instance that an outbreak of the disease was confirmed outside the tropics. The disease has reportedly affected many people in India, sub-Saharan Africa, the Indian Ocean region and south-east Asia.
Some scientists in Europe believe that the Tiger mosquitoes that carry the virus were imported on second-hand tyres from India, and had now moved to France, Spain, Croatia and Switzerland.
According to the European Centre for Disease Prevention and Control, it all began when the south Indian tourist who had caught chikungunya in India was bitten by local Aedes Albopictus mosquitoes (the so-called Tiger mosquito).
The centre said: "In 2006 a group of European public health experts convened by ECDC concluded that there was a potential risk of chikungunya outbreaks happening in Europe, given the presence of mosquitos capable of carrying the virus in several European countries.
"At the end of August, Italy notified its EU partners of an outbreak of chikungunya in the district of Ravenna in North-Eastern Italy, which seems to have started after a traveller who had caught chikungunya in India was bitten by the so-called Tiger mosquito. As of today around 200 suspected cases of chikungunya have been reported in the Ravenna outbreak".
Health officials said that earlier there were stray cases of the disease in Europe but only among people who had been infected abroad, particularly in Africa and India. The latest outbreak is said to be the first time that local transmission of the disease - not just importation - had taken place.
Bettina Menne, an official of the World Health Organisation, said: "We cannot say that the disease was caused by climate change, but the conditions in Italy are now suitable for the Tiger mosquito."
A UN report on climate change released here this week on climate changed predicted that rising world temperatures would bring more exotic diseases to Europe. The 980-page report from the Intergovernmental Panel on Climate Change forecast more deaths from heatwaves, an increase in skin cancer and higher pollen counts.
More freak weather, including floods and droughts, was also on the way, the report said.