Over the years, there have been many advancements and improvements made in HIV (Human Immunodeficiency Virus) testing. Early tests developed in the 1980s, such as the Western blot test, can take months for an infected individual to test positive. The combination test (also known as the 4th generation test) used today, is now considered the recommended standard of testing by the Centers for Disease Control and Prevention (CDC).
The reason for the delay in detection using tests like the Western blot antibody test is due to the somewhat lengthy amount of time it takes for an individual to accumulate sufficient antibodies to indicate a positive result. The detection window period for such tests is 90 days, whereas the combination test has a window period of only two weeks.
Another difference in these two types of tests is that the combination test, as its name suggests, tests for both HIV antibodies as well as antigens (foreign substances that activate the immune system) in the blood. The particular antigen that the test screens for is called p24, which is part of the virus itself and becomes present much sooner than antibodies; thus, greatly expanding the detection window period.
Telluss Good, lead community health educator for HIV and STI (sexuality transmitted infections) testing and prevention at Affinity Health Center (formerly Catawba Care Coalition) in Rock Hill, S.C., has been working in HIV testing and prevention since 2008 and says that advancements in testing, as well as strategies to address both positive and negative results, are bringing us closer to “getting to zero.”
“Getting to zero” is an initiative developed and coined by The Joint United Nations Programme on HIV and AIDS (UNAIDS), the leading advocate for accelerated, comprehensive and coordinated global action on the HIV/AIDS pandemic. The initiative aims to reach a point where there are zero new HIV infections and is anticipated to be achieved sometime between the years 2020 and 2030.
“We have a prevention strategy for negative results, and we have a prevention strategy for positive results,” says Good. “Being that we’ve come this far in evolution in terms of testing, treatment and prevention, I feel we’re moving ever so close to not only getting to zero new infections but also finding a cure for HIV altogether,” he says.
If an individual has a confirmed positive result, an HIV antiviral medication regimen is begun immediately — with the goal of lowering the individual’s viral load to zero or undetectable. According to Good, when an individual has an undetectable viral load, “there is a zero percent chance for that individual to pass the virus to another person through sexual contact.”
In the case of a negative result, depending on the individual’s level of risk regarding his or her potential for HIV infection, a medication known as PrEP (pre-exposure prophylaxis) is often prescribed. One of the most common forms of this type of medication is called Truvada and is taken once daily to prevent the infection of HIV when and if an individual is exposed to the virus.
With these two strategies for both positive and negative results, Good says that the UNAIDS vision of “getting to zero” is growing closer and closer every day.
He says when he first began working in the testing and prevention field, the standard for HIV testing was the OraQuick oral swab rapid test, which collected skin cells from inside the cheek to test for the presence of HIV antibodies. The detection window period for this type of antibody test is similar to that of the Western blot test, in that it can potentially take up to 90 days for an infected individual to test positive.
“Back then, we would do a preliminary test using the OraQuick oral swab rapid test, then if the results were positive, we would perform the Western blot test to confirm the positive results,” says Good.
The unique thing about the OraQuick oral swab test is that it is a visual test with line indicators, very similar to a pregnancy test. And while this test was once the standard for HIV testing in a professional and medical capacity, it was made available for purchase in 2012 as an at-home, rapid HIV test.
Good says that he feels this sort of testing option has helped normalize HIV testing and has contributed to an increase in individuals getting tested, in general. He also says that the CDC has utilized social media to promote HIV testing and that their efforts have greatly impacted the number of individuals getting tested as well.
“The CDC has done a great job at campaigning for the importance of testing,” says Good.
Thanks to advancements in HIV testing developed by the CDC, the virus is now able to be detected much quicker, fostering better treatment outcomes as well as prevention.
“These advances and changes in testing have been developed by the CDC, and they’re always working on making improvements and coming up with new ideas to advance and improve testing,” Good says. “A test we’ve just recently begun using is the Alere Determine test.”
The Alere Determine test is an innovative, rapid version of the combination test and is administered by collecting blood from a finger prick and putting the sample onto a collection pad. The test provides visual results with line indicators, much like the OraQuick oral swab test.
Good says there’s also another rapid HIV antibody test that’s primarily used for community testing events. The bioLytical Insti rapid test develops in just one minute and works similarly to the Alere Determine test by collecting a blood sample from a finger prick.
For individuals who have knowingly been exposed to HIV, there is an HIV RNA (ribonucleic acid, a nucleic acid present in all living cells) test, which screens for the genetic material of the virus itself and has a detection window period of nine to 11 days. While this type of test provides for optimal early detection, it’s not administered in routine HIV testing as it is very expensive.
Due to both testing advancements, as well as HIV awareness growing more rapidly each year, Good says he’s noticed a significant increase in individuals coming in to get tested, but that there has also been an increase in positive results as well.
However, he says that more positive results aren’t necessarily a bad thing.
“When a person is aware of their status, they’re able to get the proper treatment to hopefully become undetectable, which as mentioned, makes it nearly impossible to transmit the virus to another person through sexual contact,” says Good.
As the CDC continues to develop both testing and prevention strategies, Good says he feels confident that one day soon there will not even be a need for HIV testing anymore.
“It’s an enlightenment to think that one day soon we will have a time where we’re not testing anyone for HIV anymore and that those who do have the virus, will have a cure,” says Good.