Testing

The Role of Testing in HIV Prevention: Knowing your status

Through HIV testing, individuals can know their HIV status – a critical step in connecting them with services — whether for prevention or treatment.

Types of Tests

There are four different types of tests, each used for a different purpose.

1 → Rapid Diagnostic Test (RDT)

• Measures: Antigens and antibodies (The antigen is the part of the virus that triggers an immune response and antibodies are the response that fights off the germ)
• Earliest detection of HIV from four weeks to three months after exposure
• Results in 20 minutes
• WHO recommends two confirmatory tests for HIV+ result

2 → At-home Tests (Self-Testing)

• Measures: Antibodies
• Earliest detection of HIV three months after exposure
• Results in 20 minutes
• Need confirmatory test for HIV+ result

3 → Enzyme Immunoassay Test (IA or EIA) 

• Measures: Antibodies
• Earliest detection of HIV within 14 days to one month after exposure
• Results in 5-10 days
• Standard Point of Care Test in some wealthy countries. Not widely available in low- and middle-income countries

4 → Nucleic Acid Test (NAT)

• Measures: HIV RNA (It can see how much of the virus is present in someone’s blood)
• Earliest detection of HIV 10 days after exposure
• Results in a few days
• Not widely available in low- and middle-income countries
• This test can pick up if someone is infected much earlier than the other tests and is recommended for people at risk of a recent exposure to HIV

HIV Testing and PrEP

Screening for HIV status before and during PrEP use is recommended to decrease the risk of developing drug resistance. Testing should be repeated again a month after starting PrEP in case the virus was undetectable during the first screening. Self-testing is currently not advised for people starting PrEP but the evidence is under review. Simpler testing can enable the expansion of community-based PrEP services, which in turn supports increased uptake.

Increasing Access to Self-Testing

With a simple finger prick or oral swab and a 20 minute wait time, more people can have easy access to testing and increased privacy around their HIV status. Use of self-testing for HIV expanded during the COVID-19 pandemic and the WHO guidance is evolving to improve access. Advocates have fought for the inclusion of counseling and mental health services for key populations in the WHO guidance.

Testing and Advocacy

Testing can and should be part of a broad effort to bring HIV services into communities. And self testing is one element in making HIV prevention highly effective. Greater investment by donors, governments and global health entities is required to expand access to testing in communities.