PHILADELPHIA - Researchers at the University of Pennsylvania have found a link between parasites and skin secretions that contain urocanic acid.  This research supports non-governmental organizations' advocacy to use "appropriate technology" to develop inexpensive and practical treatments to prevent infections and to ward off parasitic diseases in poor, developing countries, according to a report published in the January issue of the Proceedings of the National Academy of Sciences.

Although skin-penetrating nematodes like hookworms and threadworms are drawn to body heat, Penn researchers found that a chemically based attractant, urocanic acid, served as a "cue" for S. stercoralis, a threadworm.  

Researchers also noted that for a soil-dwelling parasite, high levels of urocanic acid on the sole of a human foot might be an important part of the infection process because larvae are attracted to unprotected skin that comes into contact with the ground. These kinds of parasites are responsible for infecting hundreds of millions of people around the globe, as well as other primates and dogs.

The study revealed that metal ions could reduce the level of attraction between the parasites and the urocanic acid, potentially providing a foundation to prevent nematode infection.

Researchers who conducted the study include Daniel Safer from the Department of Physiology in Penn's School of Medicine and Gerhard Schad, Mario Brenes and Seth Dunipace from the Department of Pathobiology in Penn's School of Veterinary Medicine.