They say the drug should be tested on thousands more people, including those in different risk, age and ethnic groups.

VOA: special.2009.04.08

And they are advising against travel by children, pregnant women and other groups at highest risk.

VOA: special.2009.11.24

That's one reason doctors want to know the risk of all groups of people before heading into surgery.

VOA: standard.2010.03.11

She says children are at risk of sexual violence, killing and maiming, and forced recruitment into armed groups.

VOA: standard.2010.02.04

"There are at least 27 different indigenous groups in Colombia that are considered to be at risk of extinction largely as a result of armed conflict and forced displacement.

VOA: standard.2009.03.22

Dr.Segev says the research snows that men and African-Americans have a slightly higher risk of dying after donation than other groups, but the risk is still small and that it has nothing to do with having only one kidney.

VOA: standard.2010.03.11