According to the Centers for Disease Control and Prevention (CDC), roughly 1.2 million Americans are living with HIV. About 16 percent of people living with HIV don’t know they’ve contracted the virus.

In addition to not getting the treatment they need, they can unknowingly transmit the virus to others. In fact, 40 percent of new HIV cases are transmitted by people who are undiagnosed.

The CDC’s 2015 recommendations for HIV testing advise healthcare providers to provide routine screenings for HIV as a part of standard care regardless of any risk factors.

Despite these recommendations, many Americans have never been tested for HIV.

Anyone who hasn’t been tested for HIV should consider asking their healthcare provider for a test. They can also seek free and anonymous HIV testing at a nearby clinic.

Visit the CDC’s GetTested website to find a local testing site.

The CDC advises that routine HIV testing should be provided in all healthcare settings, especially if testing for other sexually transmitted infections (STIs) at the same time.

People engaging in behaviors that puts them at an increased risk for contracting HIV should be tested at least once a year.

Known risk factors include:

  • having multiple sexual partners
  • engaging in sex without condoms or other barrier methods
  • sex without a condom or barrier method and without pre-exposure prophylaxis (PrEP)
  • having partners with an HIV diagnosis
  • injected drug use

HIV testing is also recommended:

An HIV infection is now considered a manageable health condition, especially if treatment is sought early.

If a person has contracted HIV, early detection and treatment can help:

  • improve their frame of mind
  • lower their risk of disease progression
  • prevent the development of stage 3 HIV, or AIDS

It can also help reduce their risk of transmitting the virus to other people.

The life expectancy of people with an HIV diagnosis who start treatment early is the same as those without the virus. People who know that they’ve been exposed to HIV should seek care as soon as possible.

In some cases, if they’re treated within 72 hours, their healthcare provider may prescribe post-exposure prophylaxis (PEP).

These emergency medications may help reduce their chances of contracting HIV after they’ve been exposed to it.

A number of different tests can be used to check for HIV. These tests can be performed on blood samples or saliva samples. Blood samples can be obtained via an in-office finger prick or a blood draw in a laboratory.

Not all tests require a blood sample or a visit to a clinic.

In 2012, the U.S. Food and Drug Administration (FDA) approved the OraQuick In-Home HIV Test. It’s the first rapid test for HIV that can be performed at home using a sample from a swab inside your mouth.

If a person thinks they’ve contracted HIV, it can take anywhere from 1 to 6 months after transmission for a standard HIV test to produce positive results.

These standard tests detect antibodies to HIV rather than the virus itself. An antibody is a type of protein that fights off pathogens.

According to Avert, third-generation HIV tests — which are ELISA tests — can only detect HIV 3 months after exposure to the virus.

This is because it generally takes 3 months for the body to produce a detectable number of antibodies.

Fourth-generation HIV tests, which look for antibodies and the antigen p24, can detect HIV 1 month after transmission. Antigens are substances that cause an immune response in the body.

According to Columbia University’s Go Ask Alice!, 97 percent of people with HIV produce a detectable number of antibodies within 3 months. Although it may take 6 months for some to produce a detectable amount, this is rare.

If a person thinks they’ve been exposed to HIV, they should tell their healthcare provider. A viral load test that directly measures the virus can be used to detect whether someone has recently acquired HIV.

If a person has received an HIV diagnosis, it’s important for them to monitor their condition on an ongoing basis.

Their healthcare provider can use several tests to do this. The two most common measures for assessing HIV transmission are CD4 count and viral load.

CD4 count

HIV targets and destroys CD4 cells. These are a type of white blood cell found in the body. Without treatment, the CD4 count will decrease over time as the virus attacks the CD4 cells.

If a person’s CD4 count decreases to fewer than 200 cells per cubic millimeter of blood, they’ll receive a diagnosis of stage 3 HIV, or AIDS.

Early and effective treatment can help a person maintain a healthy CD4 count and prevent the development of stage 3 HIV.

If treatment is working, the CD4 count should remain level or increase. This count is also a good indicator of overall immune function.

If a person’s CD4 count drops below particular levels, their risk of developing certain diseases increases substantially.

Based on their CD4 count, their doctor may recommend prophylactic antibiotics to help prevent these infections.

Viral load

Viral load is a measure of the amount of HIV in the blood. A healthcare provider can measure the viral load to monitor the effectiveness of HIV treatment and the status of the disease.

When a person’s viral load is low or undetectable, they’re less likely to develop stage 3 HIV or experience its associated immune dysfunction.

A person is also less likely to transmit HIV to others when their viral load is undetectable.

People with undetectable viral loads should still continue to use condoms and other barrier methods during sexual activity to prevent transmission to others.

Drug resistance

A healthcare provider may also order tests to learn if a strain of HIV is resistant to any medications used in treatment. This can help them decide which anti-HIV drug regimen is most appropriate.

Other tests

A healthcare provider may also use other tests to monitor someone for common complications of HIV or side effects of treatment. For example, they may perform regular tests to:

They may also perform physical exams and tests to check for other illnesses or infections associated with HIV, such as:

A CD4 count below 200 cells per cubic millimeters isn’t the only sign that HIV has progressed to stage 3 HIV. Stage 3 HIV can also be defined by the presence of certain opportunistic illnesses or infections, including:

As testing advances, researchers are hoping to find pathways to a vaccine or a cure in the coming years.

As of 2020, there are over 40 approved antiretroviral drugs on the market with new formulations and methods being researched all the time.

Current testing only detects markers of the virus as opposed to the virus itself, but research is finding ways the virus can hide in immune system cells. This discovery is allowing for better understanding and more insight into an eventual vaccine.

The virus mutates rapidly, which is one of the reasons it’s a challenge to suppress. Experimental therapies such as a bone marrow transplant to treat lymphoma using stem cells are being tested for treatment potential.

If a person has received an HIV diagnosis, it’s important for them to monitor their health closely and report any changes to their healthcare provider.

New symptoms may be a sign of an opportunistic infection or illness. In some cases, it may be a sign that their HIV treatment isn’t working properly or that their condition has progressed.

Early diagnosis and effective treatment can improve their frame of mind and lower the risk of HIV progression.