Mosquito-borne African virus a new threat to West

By David Morgan, Reuters

A man walks behind a model of an Anopheles mosquito

WASHINGTON — The United States and Europe face a new health threat from a mosquito-borne disease far more unpleasant than the West Nile virus that swept into North America a decade ago, a U.S. expert said on Friday.

Chikungunya virus has spread beyond Africa since 2005, causing outbreaks and scores of fatalities in India and the French island of Reunion. It also has been detected in Italy, where it has begun to spread locally, as well as France.

"We're very worried," Dr. James Diaz of the Louisiana University Health Sciences Center told a meeting on airlines, airports and disease transmission sponsored by the independent U.S. National Research Council.

"Unlike West Nile virus, where nine out of 10 people are going to be totally asymptomatic, or may have a mild headache or a stiff neck, if you get Chikungunya you're going to be sick," he said.

"The disease can be fatal. It's a serious disease," Diaz added. "There is no vaccine."

Chikungunya infection causes fever, headache, fatigue, nausea, vomiting, muscle pain, rash and joint pain. Symptoms can last a few weeks, though some suffers have reported incapacitating joint pain or arthritis lasting months.

The disease was first discovered in Tanzania in 1952. Its name means "that which bends up" in the Makonde language spoken in northern Mozambique and southeastern Tanzania.

The virus could spread globally now because it can be carried by the Asian tiger mosquito, which is found in Asia, Africa, Europe, the Americas, Australia and New Zealand.

In the United States, the mosquito species tends to live in southern regions east of the Mississippi but has been found as far afield as western Texas, Minnesota and New Jersey.

Health officials are greatly concerned about the appearance of Chikungunya in the islands of the Indian Ocean -- Mauritius, Seychelles and Reunion -- which have beach resorts frequented by European tourists.

"It is hyper-endemic in the islands of the Indian Ocean," Diaz told the meeting.

"Travel by air will import the infected mosquitoes and humans," he added. "Chikungunya is coming."

Diaz warned of possible double-infections involving Chikungunya and dengue fever or malaria, which are also carried by the Asian tiger mosquito.

The spread of the disease could be greatest in so-called mega-cities such as Mumbai and Mexico City, which have large and impoverished populations, poor health controls and water systems that provide ready breeding grounds for mosquitoes, Diaz said.

West Nile, spread by a different mosquito species, first appeared in New York in 1999 and now can be found in most of North America.