HIV is a virus that attacks the immune system. The virus specifically attacks a subset of T cells. These cells are responsible for fighting infection. When this virus attacks these cells, it reduces the overall number of T cells in the body. This weakens the immune system and can make it easier to contract certain illnesses.

Unlike other viruses, the immune system can’t get rid of HIV completely. This means that once a person has the virus, they’ll have it for life.

However, a person living with HIV who’s on regular antiretroviral therapy can expect to live a normal life span. Regular antiretroviral therapy can also reduce the virus to undetectable levels in the blood. This means that a person with undetectable levels of HIV can’t transmit HIV to a partner during sex.

Transmission through sex

One way HIV is transmitted is through condomless sexual intercourse. This is because the virus is transmitted through certain bodily fluids, including:

  • pre-seminal fluids
  • semen
  • vaginal fluids
  • rectal fluids

The virus can be transmitted through condomless oral, vaginal, and anal intercourse. Sex with a condom prevents exposure.

Transmission through blood

HIV can also be transmitted through blood. This commonly occurs among people who share needles or other drug injection equipment. Avoid sharing needles to reduce the risk of HIV exposure.

Transmission from mother to child

Mothers can transmit HIV to their babies during pregnancy or delivery through vaginal fluids. Mothers who have HIV can also transmit the virus on to babies through their breast milk. However, many women who are living with HIV have healthy, HIV-negative babies by getting good prenatal care and regular HIV treatment.

Healthcare providers typically use an enzyme-linked immunosorbent assay, or ELISA test, to test for HIV. This test detects and measures HIV antibodies in the blood. A blood sample via a finger prick can provide rapid test results in less than 30 minutes. A blood sample through a syringe will most likely be sent to a lab for testing. It generally takes longer to receive results through this process.

It usually takes several weeks for the body to produce antibodies to the virus once it enters the body. The body typically generates these antibodies three to six weeks after exposure to the virus. This means that an antibody test may not detect anything during this period. This is sometimes called the “window period.”

Receiving a positive ELISA result doesn’t mean that a person is HIV-positive. A small percentage of people may receive a false-positive result. This means the result says they have the virus when they don’t have it. This can happen if the test picks up on other antibodies in the immune system.

All positive results are confirmed with a second test. Several confirmation tests are available. Typically, a positive result must be confirmed with a test called a differentiation assay. This is a more sensitive antibody test.

HIV tests are highly sensitive and may result in a false positive. A follow-up test can determine whether a person truly has HIV. If the results from a second test are positive, a person is considered to be HIV-positive.

It’s also possible to receive a false-negative result. This means the result is negative when in reality the virus is present. This generally happens if a person recently contracted HIV and gets tested during the window period. This is the time before the body has started producing HIV antibodies. These antibodies typically aren’t present until four to six weeks after exposure.

If a person receives a negative result but has reason to suspect that they’ve contracted HIV, they should schedule a follow-up appointment in three months to repeat the test.

If a healthcare provider makes an HIV diagnosis, they will help determine the best treatment. Treatments have become more effective over the years, making the virus more manageable.

Treatment can start right away to reduce or limit the amount of damage to the immune system. Taking medication to suppress the virus to undetectable levels in the blood also makes it virtually impossible to transmit the virus to someone else.

If a person receives a negative test result but isn’t sure if it’s accurate, they should get retested. A healthcare provider can help determine what to do in this situation.

It’s recommended that people who are sexually active take the following precautions to reduce the risk of contracting HIV:

  • Use condoms as directed. When used correctly, condoms prevent bodily fluids from mixing with a partner’s fluids.
  • Limit their number of sexual partners. Having multiple sexual partners increases the risk of exposure to HIV. But sex with a condom can reduce this risk.
  • Get tested regularly and ask their partners to get tested. Knowing your status is an important part of being sexually active.

If a person thinks they’ve been exposed to HIV, they can go to their healthcare provider to get post-exposure prophylaxis (PEP). This involves taking HIV medication to reduce the risk of contracting the virus after possible exposure. PEP must be started within 72 hours of potential exposure.