Parasitic disease found in blood near border

A large study of blood donations collected from two U.S. border states found that nearly one in 5,000 was positive for Chagas' disease, a potentially fatal parasitic disorder endemic in Latin America, according to a federal report.

In a separate study, the Centers for Disease Control and Prevention (CDC) disclosed that adults in three states -- Missouri, California and Washington -- contracted measles last summer after traveling to China to adopt children.

Both studies, published in the current issue of the CDC's Morbidity and Mortality Weekly Report, show how infectious diseases are entering the United States through immigration and foreign travel.

Chagas' disease affects an estimated 11 million people throughout Latin America, and nearly a third suffer chronic cardiac or gastrointestinal illnesses. Cardiac conditions include a diseased heart, irregular heartbeat and sudden death.

Dr. Louis V. Kirchhoff, a Chagas' disease specialist at the University of Iowa's medical school, has estimated that as many as 10 percent of the Mexicans who migrate to the United States are infected.

The disease is caused by the blood-borne parasite Trypanosoma cruzi. In endemic areas, it is transmitted primarily by triatomine insects commonly known as "kissing bugs."

Infection also may occur via blood transfusion, congenital transmission, organ transplantation, laboratory incident and ingestion of triatomine-tainted food or drink.

The American Red Cross compiled data from the blood-donation screening for Chagas' disease after analysis of 148,969 blood samples collected from August to last month from blood centers in Los Angeles and Oakland, Calif., and in Tucson, Ariz.

A study conducted in 2005 involved about 40,000 blood donors. That clinical trial found no blood samples positive for Chagas' disease.

The Red Cross and Blood Systems Inc., collection agencies that are responsible for nearly two-thirds of the nation's blood supply, began screening for Chagas' disease on Jan. 29.

In a statement about the measles study in the Morbidity and Mortality Weekly Report, the CDC said, "It is increasingly rare to see certain vaccine-preventable diseases in this country, especially among adults."

The authors of the study about three American women in their late 30s who contracted measles in July and August after visiting China to adopt babies wrote: "Diseases that are no longer endemic in the United States continue to occur among travelers, often resulting in delayed recognition and delayed notification of public health authorities."

The Missouri, California and Washington women were among a group of 11 U.S. families that flew to China last summer to adopt children from three orphanages in Guangdong province.

All developed skin rashes when they returned to the U.S. Diagnosis was delayed while health care providers considered other causes such as Rocky Mountain spotted fever and an allergic reaction to penicillin. The women said they had been vaccinated against measles as children, but the vaccinations could not be documented.

The women all "recovered fully" and did not infect anyone else, the authors said.