Dengue fever, that painful disease once largely confined to the dense tropics, is on a global rebound and threatening the United States.
The neighboring epidemic began worrying U.S. health officials this week, with reports of 400 dengue cases in Mexico, some near the Texas border.Texas last week began notifying 14,000 physicians to watch for dengue, and is examining hospital records to ensure that the disease hasn't been missed already.
Some 50,000 cases of the mosquito-borne viral disease have been reported in Central America this summer. Its more dangerous cousin, dengue hemorrhagic fever, has struck several hundred people in at least 15 countries in the region.
The main dengue-carrying mosquito now lives here and more travelers are coming home infected.
"The U.S. is ripe for dengue to establish itself here," said Dr. Stephen Ostroff of the Centers for Disease Control and Prevention.
Sanitation officials are urging residents of the lower Rio Grande valley to get rid of everything, from flowerpots to old tires, where mosquitos could breed. An inch of water in a container as small as a coffee cup is enough for mosquitos to hatch.
Dengue rarely kills and is spread only by mosquito bites, not person-to-person. But it is painful, with a high fever that may last a week, intense headache, joint pain and diarrhea.
"Think of the worst case of influenza and this is worse," said Jeff Taylor of the Texas Health Department. "You don't want to get this."
Doctors can only treat the symptoms of the illness, using drugs to reduce fever, relieve pain and to replace lost fluids.
The hemorrhagic version makes patients' blood vessels leak, sending them into shock if not promptly treated with fluids. Some patients require transfusions to control bleeding.
Dengue has been around for at least 200 years, but by the 1970s, mosquito control programs had largely contained it to southeast Asia.
That suddenly changed in the 1980s. Dengue reinvaded the Caribbean, recalled CDC dengue expert Duane Gubler. Then it hit Brazil, Peru, Panama, Bolivia and Ecuador, countries that hadn't seen dengue in at least 50 years. Africa had its first recorded outbreaks. Taiwan had its first cases in 35 years. The hemorrhagic strain hit Sri Lanka and India for the first time.