JACKSON (AP) — Mississippi spent about $3 million over the last decade on premarital syphilis screening the Department of Health says is unnecessary.

Mississippi is the only state that still requires couples to take blood tests before marriage, though the District of Columbia also still mandates a test.

A bill sponsored by Rep. Sydney Bondurant, who is a physician, and endorsed by the state Department of Health was killed in the House during the last session and it looks like the requirement is here to stay despite evidence against its usefulness.

A decade-old study by the Institute of Medicine questioned the effectiveness of premarital blood tests. The institute recommended ending the tests because so few syphilis cases are actually detected among engaged couples.