Threat from Chagas disease in Texas higher than expected
MedWire News: Chagas disease, a tropical parasitic disease that can be life-threatening, may be more common in the state of Texas, USA, than previously thought, say researchers.
Chagas disease, caused by the parasite Trypanosoma cruzi, is a serious public health problem in many areas of Latin America causing heart, digestive, and immunologic problems.
It is becoming more common in southern areas of the USA, such as Texas, but although the parasite is known to be endemic in this state, it is not a reportable condition, blood donor screening for the parasite is not required, and serologic human and canine profiles for this area are not available.
To assess the threat posed from Chagas disease in Texas in more detail, Sahotra Sarkar (University of Texas, Austin) and colleagues collected data on the number and distribution of "carrier" triatomine bugs in the district post 1960, the number of hospitable habitats for the bugs, and the number of recorded human infections. This information was then used to create epidemiologic risk maps to estimate which areas are at particular risk for the condition.
"We've been studying this for four years now, and this year the number of disease-causing insects is quite amazing," said Sarkar.
Eleven counties - Bee, Bexar, Brooks, Cameron, BeWitt, Goliad, Hidalgo, Jim, Wells, Kenedy, and Kleberg - in the far south of the state were estimated to have the greatest risk for Chagas outbreaks.
Writing in the journal PLoS Neglected Tropical Diseases, the researchers recommend that Chagas should be made a reportable disease in Texas, as it currently is in the states of Arizona and Massachusetts.
They explain that this is important as it can be easy to mistake the symptoms of Chagas for influenza at first, especially if clinicians are not familiar with the disease.
The team adds that blood donors should be screened for the parasite, at least in the Southern part of the state (lower than 30°N) if not in the more northern areas.
Finally, Sarkar and co-authors suggest that humans and canines should be regularly tested for Chagas disease antibodies in high-risk counties of Texas.
"The Southern Cone Initiative has interrupted the transmission of Chagas disease in several South American countries; similar efforts are being attempted for the countries of central America," say the researchers.
"We recommend that a similar international initiative be undertaken by the United States and Mexico in the trans-border region (and not restricted to Texas within the United States) to control the spread of Chagas disease," they conclude.
By Helen Albert