Today is the 20th World AIDS Day...

This is a good day for a wake-up call.

AIDS still cannot be cured. About 40,000 persons in the United States become infected with HIV each year, according to the Centers for Disease Control and Prevention. Also, one person in five among the 1.1 million Americans who are infected with the AIDS virus doesn't know it.

Though scientists recommended two years ago that HIV tests should be done as commonly as cholesterol tests, there has been little progress. One problem is that too many physicians don't understand the ease of today's rapid tests, which can cost as little as $15, according to the AP.

Of all racial and ethnic groups in the United States, HIV and AIDS have hit African Americans the hardest. Although African Americans account for less than a quarter of the U.S. population, nearly half of the people who get HIV and AIDS are black, according to the CDC.

On World AIDS Day, Public Health is emphasizing two messages: getting screened and avoiding risky behaviors, It's important to know your health status, so you can take steps to protect yourself and others.