A tropical virus that has caused severe illness and widespread panic on the islands of the Indian Ocean has become established in Europe for the first time.

The Ministry of Health in Italy has confirmed a* outbreak of Chikungunya virus near Ravenna in the region of Emilia Romagna, 200 miles north of Rome. A total of 151 cases were reported in two villages near the town of Cervia between 4 July and 3 September. Eleven patients were taken to hospital; one died.

It is the first time indigenous transmission of the virus has been detected in Europe and raises the threat that it could spread to other countries, including the UK. The virus is transmitted by the mosquito Aedes albopictus which is common in southern Europe and has been found as far north as Belgium.

The European Centre for Disease Control and Prevention (ECDC) yesterday warned travellers to Emilia Romagna to use insect repellent and sleep under mosquito nets. Pregnant women and those with chronic illnesses were urged to seek medical advice before visiting the area.

"The province of Ravenna should now be considered as an area where transmission of Chikungunya virus is occurring," the centre said. The outbreak is thought to have been caused by a traveller from India who returned with the virus from the subcontinent where there were more than 1.4 million suspected cases recorded in 2006.

Chikungunya virus caused panic on the French island of La Réunion in the Indian Ocean in 2005 and 2006 when an epidemic infected 180,000 people, a quarter of the population, and killed almost 100. Mauritius, Madagascar and the Seychelles also recorded thousands of cases. The virus causes fever, muscle and joint pain, conjunctivitis and bleeding from the nose and ears.

The infection usually last three to five days and most patients recover after a few weeks but up to one in 10 are left with chronic joint pain, stiffness and swelling.

Lee Jong-wook, who was director general of the World Health Organisation, intervened to calm public fears in La Réunion last year by emphasising the virus was rarely deadly.

The mosquito Aedes albopictus bites during the day, usually at dawn and dusk. The same species transmits dengue fever in the tropics. In the UK, 133 people returned from trips abroad infected with Chikungunya virus last year. The mosquito has been found across in Antwerp but no transmission of the infection within Britain has been recorded.

There is no treatment for Chikungunya disease and no vaccine against it. The only preventive measure is to avoid being bitten. The Foreign Office urged people travelling to affected areas to use insect repellent and wear long-sleeved garments and long trousers.

Professor Johan Giesecke, chief scientist of ECDC, said yesterday: "This is the first known transmission of Chikungunya virus in Europe. It is not a banal disease - in the outbreak in the Indian Ocean one in 1,000 of those infected died. Even if you don't die it is an unpleasant disease, causing pains in the joints." There was potential for the disease to spread because the mosquito was present in "many areas in southern Europe," he said.

A report on the virus by experts assembled by the ECDC last year concluded that "it is certain that the species [Aedes albopictus] will be able to transmit the virus in Europe, in particular during humid summer months." Airlines should warn passengers from affected countries of the risks and fact sheets on the virus should be given to doctors.

Medical staff should be warned about the risks of handling blood samples and the capacity of European laboratories to handle an upsurge in demand for tests should be checked, it said.