(Reuters Health) - People can test themselves at home to see if they’re infected with HIV, and that might help reduce the number of undiagnosed infections, researchers say.

In a study of a new in-home HIV screening test, most participants were able to follow the instructions and get a valid result, researchers found.

In addition, most of them correctly interpreted the test results.

The test kit, developed in the UK and known as the BioSure HIV Self-Test (bit.ly/2ljai26), requires a drop of blood and is available in Europe for about £30 (about US$40). Before it was approved for self-testing, the same technology was already being used to test for HIV in doctors’ offices.

“In order for any HIV self-test to be approved for sale to the general public . . . it is necessary to show that people will be able to perform the test correctly by themselves,” study coauthor Dr. John Saunders of the Institute for Global Health at the University College London told Reuters Health by email.

“The findings were very reassuring,” he added. “They showed that the majority of people were able to perform the test and interpret the result correctly. This has meant that the self-test kit can now be sold to the general public, and this increases people’s choices for how they would like to test for HIV.”

Between 2014 and 2016, researchers recruited 200 participants over age 16 from a large sexual health clinic in London. Ninety percent were male, and about 75% were white.

As reported online September 18 in Sexually Transmitted Infections, the study - which was funded by the test’s manufacturer - had two parts. First, participants were given the test kits and asked to follow the instructions and complete the self-test while researchers observed them.

During the second part of the study, participants were given three dummy tests to see if they could accurately interpret test results as positive, negative, or invalid.

About 97% of the participants completed the test properly, and 94% of participants were able to read the dummy results correctly.

An HIV self-test provides several advantages, said Saunders.

“This will help to diagnose HIV before people become unwell and reduce HIV transmission by decreasing the number of people living with undiagnosed HIV infection and increasing the number of people successfully treated so that they are no longer infectious,” he said.

However, Saunders said, anyone who is testing for HIV, regardless of how and where the test will be done, may want to talk to a health professional beforehand and think about what they’ll do when they get the result.

Also, he pointed out, the self-test kit cannot reliably detect HIV infection that was acquired within the previous three months. “People concerned about a more recent exposure risk should consider other methods for testing and seek advice from health care providers,” he said.

In the United States, according to the U.S. Centers for Disease Control and Prevention (CDC), two home tests have been approved by the U.S. Food and Drug Administration. The Home Access HIV-1 Test System, which costs about US$60, requires the user to collect a drop of blood that must be sent to a lab for the actual testing. The user calls the lab, anonymously, for the test result.

The OraQuick In-Home HIV Test, which costs about US$40, looks for the virus in saliva, rather than in blood. Test results are available in about 20 minutes, but about 1 in 12 people who actually have the infection will get a result that incorrectly says they’re negative for it, the CDC says.

SOURCE: bit.ly/2hadmce

Sex Transm Infect 2017.