SSS 2011-02-22（在线收听）

This is Scientific American’s 60-Second Science. I’m Steve Mirsky. Got a minute?

A new development in malaria:

“Plasmodium vivax, the world’s most common malaria parasite, now infects people previously considered to be resistant.”

Peter Zimmerman from Case Western Reserve University school of medicine spoke at the AAAS meeting in Washington on February 19th.

“So, red blood cells of most African people do not express the Duffy blood-group protein. Now, the Duffy blood-group protein is essentially necessary for Plasmodium vivax to get into the red cell. Duffy-negative Africans have been considered to be resistant to Plasmodium vivax.”

Zimmerman studied Malagasy populations on Madagascar. He found that 10 percent of Duffy-negative subjects were in fact infected with Plasmodium vivax.

“So we’ve shown that Plasmodium vivax has cleared Duffy negativity. If Plasmodium vivax is evolving to learn how to infect the Duffy-negative red cell, then a large continent of people suddenly becomes susceptible to a new form of malaria.”