Killer Brazilian Caterpillars

It sounds like a scene from a horror movie: A 52-year-old Brazilian woman brushed against a caterpillar while she was picking plums, and a few days later she died a horrible death after developing bruises all over her body and lapsing into a coma. She was a victim of venom the insect injected into her skin.

The case, reported in today's issue of The Lancet, is the latest example of what researchers believe is a rising incidence of such deadly encounters. The tragedy occurred in the Passo Fundo region of southern Brazil. Health officials there have documented more than 600 cases of caterpillar poisoning since 1989, including 12 deaths. "We believe some kind of ecological disturbance in this region" has increased the number of human-caterpillar encounters, says lead author Hui Wen Fan, a physician at São Vicente de Paulo hospital in Passo Fundo.

The venom of the offending species, Lonomia obliqua, inhibits human blood from clotting. Most fatalities occur from uncontrolled bleeding in people over 50, Fan says.