One of the earliest indications of HIV infection is a fever. This indicates the virus is multiplying rapidly, and the body is trying to fend off the infection.

A fever usually occurs within 2–4 weeks of a person contracting HIV. It can occur alongside other symptoms that people may mistake for the flu or mononucleosis.

This article will explain how to tell if a fever is related to acute HIV infection.

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When a person contracts HIV, their immune system responds by creating antibodies to defend themselves. This stage of acute HIV infection is known as “seroconversion.”

As the body tries to kill off harmful pathogens, its temperature rises, resulting in a fever.

Fever is usually the first of several symptoms that occur after contracting HIV. It can involve a low to high-grade fever. Doctors consider fever to be anything over 100.4°F (38°C).

Around 40–90% of people who contract the virus develop an acute reaction that can include fever. These symptoms can last about 2 weeks. In some cases, the symptoms may go away after just a few days or last for several months.

Conversely, some people may not show symptoms of acute HIV.

A fever is not the only symptom a person may experience when they first contract HIV.

Signs and symptoms of acute infection usually resemble the flu. These include:

  • chills
  • fatigue
  • muscle aches
  • night sweats
  • rashes
  • sore throat
  • swollen lymph nodes
  • ulcers in the mouth

While these symptoms can closely resemble those of other illnesses, people who have had exposure to HIV should speak with a healthcare professional if they experience them.

Some symptoms, such as rash or mouth sores, are more likely to be related to HIV than the flu.

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There are three types of HIV tests. Each test has a specific timeframe, after which the screening will be accurate.

  • Antibody tests: A person can perform these tests at home with a finger prick or oral swab. The tests work by identifying antibodies that occur in response to the virus. These screenings are only accurate at least 23–90 days after a person’s exposure to HIV.
  • Antigen or antibody tests: These tests rely on blood from a vein that a person sends to a lab or from a finger prick involving rapid at-home tests. They look for antibodies and a viral protein called p24 antigen in the blood. These tests are accurate at least 18–90 days following a person’s exposure to HIV.
  • Nucleic acid tests: A healthcare professional conducts these tests and takes blood from a person’s vein before sending it to a lab. A lab test can determine whether the virus is in the blood and how much is present. Health experts consider these tests accurate 10–33 days after exposure to HIV.

Because every HIV test has a different window of accuracy, anyone who receives a negative test result should repeat the test several weeks later. Healthcare professionals can offer more guidance on this.

There are many treatments for people with HIV, and medical professionals consider the infection a chronic condition. However, early detection of HIV helps ensure a better outlook for those who contract it. If they seek treatment early, people with the infection may live just as long as those without the virus.

People who contract HIV but do not get a diagnosis during stage 1, the acute stage, may see their condition proceed to stage 2, the clinical latency stage.

In the clinical latency stage, HIV does not reproduce as rapidly as before. A person may not have a fever or other acute symptoms, but the virus continues to replicate.

Ideally, a person living with HIV should receive a diagnosis during the first two stages and seek treatment. For many people, treatment makes the condition effectively undetectable.

If a person does not receive treatment, the virus continues to replicate in their body and will progress in about 10 years to AIDS, which is stage 3. In some cases, reaching this stage can take a shorter time.

A person with AIDS is more vulnerable to infections because their immune system has weakened and does not work properly. It cannot fend off HIV and other bacteria, viruses, or fungi, exposing someone to life threatening illnesses.

Researchers have not established a cure for HIV, but medication can reduce its levels in the body and halt its progression.

Antiretroviral therapy uses a combination of HIV medications to keep the virus from replicating. When it does that, the body can boost its number of CD4+ cells, the white blood cells in the immune system that fight infection. Over time, a person’s viral load can become undetectable. Their long-term prognosis and overall health usually get better.

Undetectable HIV is also untransmittable, meaning a person cannot spread it to anyone else.

Fever can be one of the first symptoms of an acute HIV infection. A person may also experience other flu-like symptoms for a week to a month.

Anyone who thinks they may have had exposure to HIV should speak with a doctor about getting tested for it, even if they do not have symptoms.

With the latest innovations in medical treatment, HIV has become a manageable health condition. People living with the infection can arrange treatment and go on to live long and healthy lives.