Tropical disease invades a warming Italy

New York Times: Panic was spreading through this tidy village of 2,000 in August as one person after another fell ill with weeks of high fever, exhaustion and excruciating bone pain, just as most of Italy was enjoying Ferragosto, its most important summer holiday.

… By midmonth, more than 100 people had come down with the same malady. Although the worst symptoms dissipated after a couple of weeks, no doctor could figure out what was wrong.

People blamed pollution in the river. They denounced the government. But most of all they blamed recent immigrants from tropical Africa for bringing the pestilence to their sleepy settlement of pastel stucco homes.

Oddly, the villagers were both right and wrong. After a month of investigation, Italian public health officials discovered that the people of Castiglione di Cervia were, in fact, suffering from a tropical disease, chikungunya, a relative of dengue fever normally found in the Indian Ocean region. But the immigrants spreading the disease were not humans but insects: tiger mosquitoes, which can thrive in a warming Europe.

Aided by global warming and globalization, Castiglione di Cervia has the dubious distinction of playing host to the first outbreak in modern Europe of a disease that had previously been seen only in the tropics.

"By the time we got back the name and surname of the virus, our outbreak was over," said Dr. Rafaella Angelini, director of the regional public health department in Ravenna. "When they told us it was chikungunya, it was not a problem for Ravenna any more. But I thought: 'This is a big problem for Europe.' "

The epidemic proved that tropical viruses are now able to spread in new areas, far north of their previous range. The tiger mosquito, which first arrived in Ravenna three years ago, is thriving across southern Europe and even in France and Switzerland. And if chikungunya can spread to Castiglione - "a place not special in any way," Angelini said - there is no reason why it cannot go to other Italian villages. There is no reason why dengue, an even more debilitating tropical disease, cannot as well.

"This is the first case of an epidemic of a tropical disease in a developed, European country," said Dr. Roberto Bertollini, director of the World Health Organization's Health and Environment program. "Climate change creates conditions that make it easier for this mosquito to survive and it opens the door to diseases that didn't exist here previously. This is a real issue. Now, today. It is not something a crazy environmentalist is warning about."

…But the biggest mystery is whether chikungunya will emerge here next summer. In the tropics, it is a year-round disease, because the mosquitoes breed continually. But the virus can winter over in mosquito eggs, too, and no one knows if there are reservoirs of sleeping eggs in some pool of water in Italy.