Doctors need to be thinking about whether their patients have a risk of becoming infected with the AIDS virus and, if they do, should recommend a daily pill to protect themselves, a national task force said Tuesday

It’s the first time the U.S. Preventive Services Task Force has recommended what’s called pre-exposure prophylaxis or PrEP to help stop the spread of HIV.

“The evidence is clear: when taken as prescribed, PrEP is highly effective at preventing HIV,” Dr. Seth Landefeld, a member of the independent task force, whose advisories guide medical practice and, often, federal policies, said in a statement.

“To make a difference in the lives of people at high risk for HIV, clinicians need to identify patients who would benefit and offer them PrEP, added Landefeld, who chairs the department of medicine at the University of Alabama at Birmingham School of Medicine.

The USPSTF also renewed its 2013 recommendation that doctors test all teens and adults aged 15 to 65 for HIV, especially pregnant women. HIV experts say universal screening can reduce the stigma associated with getting HIV testing and can also catch cases that would otherwise go undetected.

The human immunodeficiency virus infects 36 million people globally and it has killed 35 million people since it began spreading in the 1970s, according to the World Health Organization.

In the United States, more than 1.2 million people have HIV, and close to 40,000 people are newly infected each year.

PrEP can reduce the risk of catching HIV by 90 percent if people use it consistently. It's been on the market since 2012 and has been recommended by the Centers for Disease Control and Prevention since 2014.

In the U.S., researchers have estimated that 1.1 million people should be taking PrEP. But a CDC study published in October showed that only 78,000 Americans are actually taking it.

The USPSTF says those at high risk who should be offered PrEP include:

Anyone without HIV who has an HIV-positive sex partner

Gay, bisexual or transgender men who have had a recent sexually transmitted infection

Gay and bisexual men who do not use condoms every time they have sex

Heterosexual or transgender women who do not consistently use condoms with a high-risk sex partner, such as a bisexual man or someone who injects drugs

Women who have had a recent STI

Injecting drug users who share equipment

"Consistent use of condoms decreases risk of HIV acquisition by approximately 80 percent and also decreases the risk of other STIs," the USPSTF said.

"However, condoms are often used inconsistently by sexually active adults. PrEP should be considered as an option to reduce the risk of HIV acquisition in persons who use condoms inconsistently, while continuing to encourage and support consistent condom use."

There's also evidence that HIV-positive people are less likely to transmit the virus to their sexual partners if they have the virus controlled using drug cocktails. The USPSTF said there's not enough evidence to say whether giving PrEP to the uninfected partner reduces the risk even more.

One product, Gilead’s two-drug combination pill Truvada, is approved for use as PrEP. But the USPSTF noted that several studies have found that a pill called tenofovir, used alone, is also effective as PrEP, and can be considered as an alternative for high-risk heterosexual men and women and drug users.