A new public health hazard has arrived in the Lower Rio Grande Valley: a bug indigenous to Central and South America carrying a parasite that can cause potentially fatal heart and digestive problems.
The insect is commonly known as the kissing bug -- chinche in Spanish -- and can carry a protozoan parasite called Trypanosoma Cruzi, which can cause potentially lethal Chagas disease, The Monitor of McAllen reported Sunday.
At highest risk along the border are Hidalgo and Cameron counties, said Teresa Patricia Feria, an assistant biology professor at the University of Texas-Pan American in Edinburg who is leading the effort to collect the bug found around the Valley.
"We don't want people to panic. They just need to be aware of the possibility of the existence of this disease in the area," said Sahotra Sarkar, a professor of integrative biology and philosophy at the University of Texas at Austin who is studying Feria's samples. Sarkar, who has studied the bug for four years, expects to submit his final results next month.
Carbon dioxide in human breath attracts the kissing bug to a person's face, usually around the eyes or mouth, Feria said. The bug feeds on blood, but the bite itself is not the transmitting mechanism for the disease.
Rather, the parasitic microbe is found in its waste, which the bug deposits on the skin when it feeds and contaminates the bloodstream when the host scratches the resulting swelling and itch.
The disease is often difficult to detect in its early stages, although some develop a fever during the initial phase.
"The symptoms you are getting are kind of nonspecific," said Brian Lund Fredensborg, another UTPA assistant biology professor.
Only 10 to 15 years later do acute heart and digestive problems show themselves, he said.
Only blood tests can diagnose Chagas disease, he said. The blood sample must be sent to the U.S. Centers for Disease Control and Prevention, where results can often take weeks, said Dr. Luis Padula, a cardiologist.
No cases have been reported from South Texas, Padula and other cardiologists told The Monitor. United Blood Services, which provides donated blood in the Valley, regularly tests its blood for the organism, said its Rio Grande Valley director Frank Esparza. One unit tested positive in 2009, and again in 2010.
"When we get a positive (test), we don't use it," Esparza said.
The New England Journal of Medicine estimates that between 8 million and 10 million people are infected, most of them in the Western Hemisphere. An estimated 300,000 live in the U.S., most of them immigrants from where the disease is common.
The Texas Department of Health and Human Services is waiting for Sarkar's report before deciding whether to make the disease reportable to the state, agency spokeswoman Carrie Williams told the newspaper.