Acute HIV infection, also known as “primary HIV infection,” is the first stage of HIV.
During the acute period of infection, the level of virus in a person’s blood is very high as their body is not yet able to mount an immune response.
When to see a doctor
The signs of acute HIV infection can be easily mistaken for the symptoms of different illnesses. Conventional HIV tests may not detect acute HIV infection, so misdiagnoses are common.
If a person experiences these symptoms and they think they may have recently been exposed to HIV, they should speak to their doctor about what testing options are available.
How is acute HIV infection diagnosed?
The most common HIV tests are unable to detect HIV at the acute infection stage. This is because the tests are typically designed to detect the HIV-specific antibodies that are produced by the immune system during a process called seroconversion.
It can take as little as a few weeks or as many as a few months for a person’s body to develop these antibodies. This means that someone who has recently been infected with HIV and is tested during the acute infection stage may not be diagnosed as HIV-positive.
However, a screening method called nucleic acid amplification testing or detecting an HIV-viral load (the amount of HIV in the bloodstream) can help to detect HIV infection in people who have been recently infected.
Tests that use p24 antigen detection can also help detect HIV infection before antibodies are produced.
Most people contract HIV after coming into contact with body fluids that contain the virus.
Examples of these fluids include blood, semen, vaginal fluids, and breast milk.
The virus is usually spread from person to person as a result of having sex or sharing needles with someone who has HIV.
HIV can also be transmitted from a mother to a child, both during pregnancy, birth, and through breastfeeding.
Risk and acute HIV infection
It is estimated that up to 50 percent of new HIV infections are unknowingly transmitted from people who have acute HIV infection.
Regardless of gender or sexual preference, HIV transmission is about 7.25 times more likely during acute infection than it is during chronic infection, which is the second stage of HIV infection.
The HIV transmission levels are high during the acute stage of the condition because the blood contains high levels of the virus, but no antibodies. Since acute HIV infection is difficult to diagnose, people with HIV may engage in high-risk behavior without realizing that they pose a risk to other individuals.
Receptive anal sex is the highest-risk type of sex for HIV transmission, followed by insertive anal sex, then vaginal sex, and lastly oral sex.
A 2015 study found that, among men who have sex with men, having unprotected, receptive anal sex was associated with an increase for acquiring HIV infection. This risk became more severe for men have unprotected, receptive anal sex with five or more men.
The study did not report that use of injected or non-injected drugs was significantly associated with increased risk of acute HIV infection. However, some other studies have found that drugs such as methamphetamine seem to drive risky sexual behaviors and increase risk for acute HIV infection among men who have sex with men.
Following acute HIV infection, patients enter the second stage of infection – chronic HIV infection. During chronic infection, HIV continues to multiply in the blood, but at lower levels than in acute infection. Although people with chronic HIV infection may not exhibit symptoms of HIV, they can still transmit the virus.
Without treatment, chronic infection may progress to the final stage of HIV infection within 10 years, on average, which is known as acquired immunodeficiency syndrome, or AIDS.
AIDS develops when a person’s immune system has been so badly damaged by HIV that their body is unable to fight the infections that a healthy immune system might be able to.
People with AIDS who do not receive treatment will usually die within 3 years.
However, current treatment strategies for HIV mean that most people with HIV will not develop AIDS but can continue to live a full life.
Medicines called antiretroviral drugs are commonly used to manage HIV infection. Antiretrovirals do not kill HIV or cure the condition. However, combinations of these drugs are able to prevent the growth of the virus and reduce the viral load to undetectable levels.
People who have an undetectable viral load stay healthier for longer and are significantly less likely to transmit the virus to other people compared to most people with HIV who are not taking antiretroviral medication.
If the viral load is undetectable that does not mean that the virus has gone or that the condition has been cured.
It is worth noting that ART can reduce the level of the virus in the blood to the point where it is no longer detectable. At this level, it is no longer transmissible, according to the Center for Disease Control and Prevention (CDC).
Increasingly, studies are suggesting that if a person begins antiretroviral therapy (ART) within 3 months of being diagnosed with acute phase HIV, progression of the disease is slowed down. It also helps to slow down other possible complications such as inflammation throughout the body.
Experts generally agree that the following steps help reduce risk of HIV infection:
- not injecting drugs
- getting tested for HIV and knowing the status of a partner or partners
- avoiding risky sexual behaviors
- using condoms with every sexual experience
- limiting the number of sexual partners – the more partners someone has, the higher the risk of sexually-transmitted diseases, including HIV
- discussing prevention options with your doctor
One prevention option for people at high risk of HIV is called pre-exposure prophylaxis (PrEP). This method involves taking HIV medication every day. There are also some newer PrEP options in clinical studies, which include receiving an injection every 8 weeks instead of taking a pill every day. However, PrEP is currently appropriate for:
- people who are in a sexual relationship with a partner who has HIV
- men who have sex with men who have had anal sex without a condom in the past 6 months or have been diagnosed with a sexually transmitted disease in the past 6 months
- heterosexual men and women who do not always use condoms during sex with partners who are at high risk of HIV infection
- people that have injected drugs in the past 6 months and have either shared needles or been in a drug treatment
- people with significant, ongoing risk of acquiring HIV-infection
PrEP offers effective protection against HIV infection by building up in tissues where exposure risk is highest, and preventing HIV entry and replication. This mechanism prevents transmission of HIV to a person who is not infected[MD(1] .
Condoms continue to be an important method for reducing the risk of spreading many sexually transmitted diseases.