"Similar conditions that resulted in the establishment of local transmission in Ravenna (northern Italy) apply as well in other areas of Europe where the mosquito is present, for example the southern parts of France, the coastal areas of Spain," said Denis Coulombier, head of the preparedness and response unit for the European Centre for Disease Prevention and Control (ECDC).
One expert has said that the Italian cases could be the first outbreak outside the tropics. It was apparently caused by a foreigner arriving in Italy from India.
A total of 78 cases have been confirmed in Italy, while 254 others are suspected, said Stefania Salmaso, director of the National Centre for Disease Surveillance and Health Promotion at the Italian Public Health Institute, who was among the experts in Stockholm.
Chikungunya gets its name from a Swahili word meaning "that which bends up" because of the arthritic-type symptoms that leave victims stooped.
Also causing fever, headaches and muscle pain, it has traditionally been present in eastern Africa, southeast Asia and the Indian subcontinent. Most patients eventually recover.
Increased travel to tropical locations could contribute to outbreaks in Europe, said Jean-Claude Desenclos of the French Health Monitoring Institute.
The experts said European countries must work to control tiger mosquito populations, with the insect present in Italy, France, Spain, the Netherlands, Greece and on the Portuguese island of Madeira.
They said, however, that the situation was not alarming.
"There is no real need for international action at the moment, just the risk assessment," said Salmaso.
Awareness was key for the time being, said Coulombier.
"The new development makes us want to be ready and inform more widely the health care providers, physicians, to think about the possibility of diagnosis," he said.