A chemical that causes certain parasitic worms, including hookworms, to pass from the infective larval stage to the feeding larval stage may prove useful in reducing the risk posed by these worms throughout the world. The chemical is dafachronic acid and it sends the necessary signals for the worms to mature from the stage in which they infect a host to the stage in which they start feeding on the host, which is what makes the host sick. In this study, researchers treated hookworm parasites pharmacologically at the infective larval stage with dafachronic acid, causing them to pass into the feeding larval stage outside a host, where they had no food supply and died. Treatment of other infectious species had similar effects. Dr. David Mangelsdorf, the senior author of the study, said that the next step in the research is to screen large libraries of chemicals to search for compounds that behave like dafachronic acid and that could possibly be developed into pesticides that could be spread in high-infection areas. Many infectious nematode larvae live in the soil, often in areas where proper sanitation is lacking. According to the World Health Organization, parasitic nematodes infect about 2 billion people worldwide and severely sicken some 300 million, at least 50 percent of whom are school-age children. This report on dafachronic acid will be available online in PNAS and in an upcoming article in the journal. [Press release]Login Or Register To Read Full Story