Facts About HIV Seroconversion

How It Affects Test Results, the Importance of Early Treatment, and How to Prevent it

Table of Contents
View All
Table of Contents

Seroconversion is a medical term for the time between exposure to a disease-causing pathogen and when antibodies show up in your blood. Antibodies are defensive proteins the immune system produces to help your body fight against viruses, bacteria, and other germs.

With HIV, seroconversion from initial infection to detectable antibody levels can take several weeks. During this window, false negatives can occur. This is why follow-up testing is important. Once seroconversion occurs, the HIV virus will remain in a person's body for life.

Seroconversion can be prevented through pre-exposure prophylaxis (PrEP) or post-exposure prophylaxis (PEP) treatment. In people who test positive for HIV, starting antiretroviral treatment early can help keep viral loads low or undetectable and prevent symptoms.

This article discusses seroconversion and HIV. It explains the window period for HIV testing, early HIV symptoms, treatment, and prevention.

Test tube for blood test
David Silverman / Getty Images

HIV Seroconversion and Testing

HIV seroconversion means that a person has gone from not having detectable HIV antibodies to having detectable HIV antibodies. The time from HIV exposure to seroconversion ranges from 10 to 90 days.

There are no HIV tests that can detect the virus prior to seroconversion, though some tests can detect HIV in as little as 10 to 18 days after exposure. There are three types of HIV tests available:

  • Antibody tests, which look for antibodies to HIV in blood or oral fluid, can take 23 to 90 days to detect HIV after exposure.
  • Antigen/antibody tests look for both HIV antigens and antibodies. This commonly used test can take 18 to 90 days to detect HIV after exposure.
  • Nucleic acid tests (NATs), which look for HIV RNA in the blood, can detect HIV 10 to 33 days after exposure. This type of test is not routinely used unless someone has a positive rapid HIV test or antigen/antibody test.

Testing before seroconversion can return inconclusive or false-negative results. This period of uncertainty is known as the window period. If you receive a negative HIV test after a potential exposure, the CDC recommends retesting after the window period for that test.

False negatives are more likely to occur with rapid tests than laboratory tests. For example, antigen/antibody tests using blood drawn from a vein can detect HIV seroconversion within 45 days. Rapid tests using a finger stick or saliva can take up to 90 days before getting a positive result.

False positives are extremely rare. A false positive is typically due to a technical issue or lab error, but it can also occur in people with autoimmune disorders or individuals who participated in an HIV vaccine study.

Symptoms of Early HIV Infection

Seroconversion may or may not be accompanied by any symptoms. Symptomatic infection is typically referred to as acute HIV infection or acute retroviral syndrome (ARS).

Symptoms of early HIV infection occur two to four weeks after infection in about two-thirds of newly infected individuals. These symptoms are similar to those of flu or infectious mononucleosis and may include:

  • Diarrhea
  • Fatigue
  • Fever
  • Headache
  • Joint pain
  • Muscle pain
  • Nausea
  • Rash
  • Sore throat
  • Swollen lymph glands
  • Weight loss

Because the symptoms are so non-specific, they may be misattributed to other illnesses.

A characteristic rash is one of the more telling symptoms of early HIV infection. An HIV rash typically affects the body's upper half and appears reddish, small, and flat, with non-itchy lesions. The rash can appear anywhere from one to four weeks after infection and usually resolves within five to eight days.

If you experience these symptoms and think you may have been exposed to HIV, talk to your healthcare provider about getting tested.

Early Diagnosis and Treatment

Once seroconversion occurs, a person will be HIV-positive for life. However, early diagnosis and treatment of HIV during acute infection may significantly slow the progression of the disease.

HIV is treated with antiretroviral therapy (ART), which involves multiple HIV medicines taken together as part of an HIV treatment regimen. Anyone who tests positive for HIV test should start treatment as soon as possible—even the same day.

Starting an HIV treatment regimen in the early weeks gives the virus less opportunity to establish hidden sanctuaries in tissues and cells known as latent reservoirs. Once HIV is embedded in these reservoirs, they are almost impossible to clear from the body.

When taken as prescribed, ART works to suppress the virus and lower the amount of HIV in your blood. This can help to achieve an undetectable viral load within one to six months.

Undetectable Is Untransmittable

"Undetectable" means that the amount of virus in the blood is so low that current blood tests are unable to detect them. When HIV is undetectable, it cannot be transmitted through sex to an HIV-negative partner. 

However, the HIV virus never fully disappears. Once seroconversion occurs, ART treatment must be continued to maintain undetectable status. People with HIV who have an undetectable viral load can live long and healthy lives.

Seroconversion Can Be Prevented

HIV seroconversion can often be prevented with the use of pre-exposure prophylaxis (PrEP) or post-exposure prophylaxis (PEP).

PrEP involves taking medicine before HIV exposure. It is available as a daily oral pill or longer-acting shots. When taken as prescribed, PrEP reduces the risk of HIV from sex by about 99% and HIV from injection drug use by 74%. 

PEP is used after a possible HIV exposure and involves taking oral antiretroviral medicine for 28 days. The sooner PEP is initiated after HIV exposure, the better. If started within the first 72 hours after exposure, PEP is highly effective at preventing HIV seroconversion.

PEP is only recommended for use in emergencies, such as when a condom breaks during sex with an HIV-positive partner. It should not be used in place of safer sex practices.

Summary

Seroconversion is the transition from exposure to HIV to having detectable HIV antibodies in the blood. HIV seroconversion can take between 10 and 90 days, depending on the test. False negatives are common during this window. 

Once seroconversion occurs, early treatment with antiretroviral medicines can help keep viral loads at undetectable levels. This helps to prevent symptoms and transmission of HIV. 

Seroconversion can be prevented in two ways: PrEP (before exposure) and PEP (after exposure). PrEP involves taking daily preventive medication before exposure. For high-risk individuals not using PrEP, PEP can be started within 72 hours of exposure. PEP is taken for 28 days. 

12 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. HIV testing.

  2. Centers for Disease Control and Prevention. Effectiveness of prevention strategies to reduce the risk of acquiring or transmitting HIV.

  3. US. Department of Health and Human Services: HIV.gov. HIV/AIDS Glossary. Seroconversion.

  4. Centers for Disease Control and Prevention. What is the HIV window period?

  5. Centers for Disease Control and Prevention. False-positive HIV test results.

  6. US. Department of Health and Human Services: HIV.gov. Symptoms of HIV

  7. Altman K, Vanness E, Westergard RP. Cutaneous manifestations of human immunodeficiency virus: a clinical updateCurr Infect Dis Rep. 2015;17(3):464. doi:10.1007/s11908-015-0464-y

  8. U.S. Department of Health & Human Services: HIV.gov. Guidelines for the use of antiretroviral agents in adults and adolescents with HIV.

  9. U.S. Department of Health & Human Services: HIV.gov. HIV treatment overview

  10. U.S. Department of Health & Human Services: HIV.gov.  Viral suppression and an undetectable viral load.

  11. Centers for Disease Control and Prevention. Post-exposure prophylaxis (PEP).

  12. Centers for Disease Control and Prevention. What is PEP? 

By Mark Cichocki, RN
Mark Cichocki, RN, is an HIV/AIDS nurse educator at the University of Michigan Health System for more than 20 years.