The term “HTLV-3” is an outdated and inaccurate designation for what is now scientifically known as Human Immunodeficiency Virus Type 1, or HIV-1. This article clarifies the terminology and provides information about HIV-1, covering its nature, transmission, progression, diagnosis, management, and prevention.
Understanding HTLV-3 and HIV-1
In the early 1980s, scientists raced to identify the cause of Acquired Immunodeficiency Syndrome (AIDS). Different research groups used various names for the causative agent. Dr. Robert Gallo’s team called it “HTLV-III” due to similarities with other Human T-lymphotropic Viruses (HTLVs). A French team named it “LAV” (lymphadenopathy associated virus), and another group used “ARV” (AIDS associated retrovirus).
These were later determined to be the same virus. In 1986, the International Committee on the Taxonomy of Viruses renamed it Human Immunodeficiency Virus (HIV) to avoid confusion. HIV-1 is a retrovirus that primarily targets and infects CD4+ T cells, which are immune cells. CD4 cells are crucial for coordinating the body’s immune response, and their progressive destruction by the virus weakens the immune system over time.
How HIV-1 Spreads
HIV-1 transmission occurs through direct contact with specific bodily fluids from a person with a detectable viral load. These fluids include blood, semen, pre-seminal fluid, rectal fluids, vaginal fluids, and breast milk. For transmission to occur, the virus in these fluids must enter the bloodstream of an HIV-negative person, typically through mucous membranes (rectum, vagina, mouth, or tip of the penis) or open cuts or sores.
The most common modes of transmission are unprotected sexual contact, particularly anal or vaginal sex, and sharing injection drug equipment like needles or syringes. Mother-to-child transmission can also occur during pregnancy, childbirth, or breastfeeding. While rare, HIV can also be transmitted through contaminated blood transfusions or organ transplants, though blood screening significantly reduces this risk. HIV-1 is not spread through casual contact such as hugging, sharing food utensils, or mosquito bites.
Stages of HIV-1 Infection
Without treatment, HIV-1 infection typically progresses through distinct stages, progressively weakening the immune system. The first stage, acute HIV infection, usually develops within 2 to 4 weeks after exposure. Some individuals may experience flu-like symptoms such as fever, headache, rash, muscle aches, or swollen lymph nodes, though not everyone develops noticeable symptoms. The virus multiplies rapidly in this stage, leading to a high viral load and increased transmission risk.
Following the acute stage, the infection progresses to chronic HIV infection, also known as asymptomatic HIV infection or clinical latency. In this stage, the virus continues to multiply at very low levels, and individuals often experience no HIV-related symptoms for many years, sometimes a decade or longer without treatment. Despite the lack of symptoms, the virus remains active and continues to damage immune cells.
The final and most severe stage is Acquired Immunodeficiency Syndrome (AIDS), which develops when the immune system is severely compromised. An AIDS diagnosis is made when a person’s CD4 cell count drops below 200 cells per cubic millimeter, or when certain opportunistic infections or cancers indicative of severe immunosuppression appear. Without treatment, the average survival time after an AIDS diagnosis is approximately three years.
Diagnosing and Managing HIV-1
Diagnosing HIV-1 involves tests that detect either the virus or the body’s immune response. Antigen-antibody tests, often using blood from a vein, detect both HIV antigens (viral proteins) and antibodies, typically showing a positive result within 2 to 6 weeks after exposure. Antibody tests, which look for HIV antibodies in blood or saliva, are common for rapid and at-home tests, with positive results usually appearing within 3 to 12 weeks. Nucleic acid tests (NATs) directly detect the virus’s genetic material (viral load) in the blood and can become positive earliest after exposure, often recommended if recent exposure is suspected.
Once diagnosed, HIV-1 is managed with Antiretroviral Therapy (ART), a combination of medicines from different drug classes. ART works by stopping the virus from replicating, reducing the viral load to very low or undetectable levels. Maintaining an undetectable viral load through consistent ART improves the health and life expectancy of people with HIV-1 and prevents sexual transmission of the virus to partners. Early initiation of ART is recommended for all individuals diagnosed with HIV-1, regardless of their CD4 count or symptoms, to strengthen the immune system and reduce the risk of infections.
Preventing HIV-1
Several strategies prevent HIV-1 transmission, reducing risk for individuals and communities. Consistent and correct condom use during sexual activity provides a barrier against the virus. Pre-Exposure Prophylaxis (PrEP) involves HIV-negative individuals taking specific anti-HIV medications daily or every other month via injection to prevent infection. When taken as prescribed, PrEP can reduce the risk of sexually acquired HIV by about 99% and from injection drug use by at least 74%.
Post-Exposure Prophylaxis (PEP) is an emergency measure for individuals potentially exposed to HIV-1. PEP must start within 72 hours (3 days) of potential exposure and is taken daily for 28 days. Avoiding shared needles, syringes, or other drug injection equipment significantly reduces transmission risk among people who inject drugs. For pregnant individuals with HIV-1, antiretroviral medications effectively prevent mother-to-child transmission during pregnancy, childbirth, and breastfeeding.