Measured Danger

How great is the risk of the AIDS virus being transmitted between male and female sex partners? Americans have been told both not to worry and, in a sensationalized book by Sexologists Dr. William Masters and Virginia Johnson, that AIDS is "running rampant" among heterosexuals. Now Dr. Norman Hearst and Dr. Stephen Hulley of the University of California at San Francisco have calculated the odds of heterosexual transmission. Last week in the Journal of the American Medical Association they reported that the chance of getting AIDS ranges from 1 in 500 for a single act of intercourse with an infected partner when no condom is used to 1 in 5 billion if a condom is used with a partner who has tested negative for AIDS antibodies. Their suggestion for lowering the odds: know your partner well.