HIV and AIDS: Understanding the Virus and Disease

Human immunodeficiency virus, commonly known as HIV, remains one of the most significant global health challenges of our time. Despite decades of research and medical advances, this virus continues to affect millions of people worldwide. Understanding what HIV is, how it works, and how it progresses to AIDS is essential for healthcare professionals and communities alike.

What makes HIV a retrovirus? 🔗

HIV belongs to a unique category of viruses called retroviruses. Unlike most viruses that use DNA as their genetic blueprint, retroviruses carry their genetic information as RNA. This fundamental difference is what makes HIV particularly challenging to combat.

When HIV enters a human cell, it performs a remarkable biological trick. The virus uses an enzyme called reverse transcriptase to convert its RNA genome into DNA. This process is the reverse of normal cellular function, which is exactly why these viruses are called “retroviruses.” Once the viral RNA becomes DNA, another enzyme called integrase permanently inserts this viral genetic material into the host cell’s own DNA.

This integration is what makes HIV infection lifelong. The viral DNA, now called a provirus, becomes a permanent part of the infected cell’s genetic code. The cell then unknowingly produces new virus particles as if they were its own proteins, spreading the infection throughout the body.

How HIV attacks the immune system 🔗

HIV specifically targets CD4-positive T cells, which are white blood cells crucial for coordinating the body’s immune response. These cells act as commanders in the immune system, directing other immune cells to fight infections and diseases. By attacking these cells, HIV systematically weakens the body’s ability to defend itself.

As the virus replicates, it destroys more CD4 cells. A healthy immune system typically has between 500 and 1,600 CD4 cells per cubic millimeter of blood. When HIV remains untreated, this count gradually declines. The lower the CD4 count, the more vulnerable a person becomes to infections and diseases that a healthy immune system would normally fight off easily.

The progression from HIV to AIDS 🔗

When people living with HIV don’t receive treatment, the infection typically progresses through three distinct stages. The first stage, acute HIV infection, occurs within 2 to 4 weeks after infection. During this phase, people have large amounts of virus in their blood and are highly contagious. Many experience flu-like symptoms including fever, headache, rash, and sore throat, though some have no symptoms at all.

The second stage, called chronic or asymptomatic HIV infection, can last a decade or longer without treatment. During this time, the virus continues reproducing but at lower levels. People may not feel sick or show symptoms, but they can still transmit HIV to others. This is why testing is so critical, as many people don’t know they have HIV until later stages.

AIDS, or acquired immunodeficiency syndrome, represents the most advanced stage of HIV infection. A person receives an AIDS diagnosis when their CD4 count drops below 200 cells per cubic millimeter of blood, or when they develop certain opportunistic infections. These infections, such as pneumocystis pneumonia, tuberculosis, or certain cancers like Kaposi’s sarcoma, take advantage of the severely weakened immune system. Without HIV treatment, people with AIDS typically survive about three years.

How HIV spreads between people 🔗

HIV transmission occurs through specific body fluids: blood, semen, pre-seminal fluid, rectal fluids, vaginal fluids, and breast milk. The virus is not spread through casual contact such as kissing, hugging, shaking hands, or sharing food and water. Understanding these transmission routes helps dispel myths and reduce stigma.

The most common transmission routes include unprotected anal or vaginal sex and sharing needles or syringes for drug injection. The virus can also pass from mother to child during pregnancy, childbirth, or breastfeeding. However, medical interventions have dramatically reduced this risk.

Several factors can increase transmission risk. Having other sexually transmitted infections like syphilis, herpes, or gonorrhea can increase viral load and make transmission more likely. Similarly, a person’s viral load, the amount of virus in their blood, significantly affects transmission risk. This is why treatment is not only beneficial for the person living with HIV but also crucial for prevention.

Preventing mother-to-child transmission 🔗

One of the most significant victories in the fight against HIV has been the dramatic reduction in mother-to-child transmission. Without intervention, transmission rates range from 15% to 45% during pregnancy, labor, delivery, or breastfeeding.

With proper treatment, this risk drops dramatically. When HIV medicines are taken consistently throughout pregnancy, childbirth, and breastfeeding, the likelihood of transmission drops to less than 1%. This remarkable achievement requires early HIV testing during pregnancy, immediate treatment initiation, and continued medication adherence.

Babies born to mothers with HIV also receive antiretroviral medicines for several weeks after birth as an additional protective measure. This comprehensive approach has virtually eliminated mother-to-child transmission in many countries with strong healthcare systems.

Treatment transforms HIV into a manageable condition 🔗

While there is currently no cure for HIV, antiretroviral therapy has transformed the disease from a death sentence into a manageable chronic condition. ART involves taking a combination of HIV medicines daily to suppress the virus and prevent it from multiplying in the body.

The goal of treatment is to achieve an undetectable viral load, meaning the amount of virus in the blood is so low that standard tests cannot detect it. This has profound implications: people with HIV who maintain an undetectable viral load cannot sexually transmit the virus to their partners. This principle, known as U=U (Undetectable equals Untransmittable), has revolutionized both treatment and prevention strategies.

Today’s antiretroviral medications are more effective and have fewer side effects than earlier treatments. Many people can take just one pill once a day. With consistent treatment and medical care, people living with HIV can expect to live long, healthy lives comparable to those without HIV.

Global impact and current statistics 🔗

The global HIV epidemic continues to be a major public health concern. An estimated 40.8 million people were living with HIV at the end of 2024, with 65% in the WHO African Region. In 2024, approximately 630,000 people died from HIV-related causes, and about 1.3 million people acquired HIV.

However, there is reason for hope. Progress has been substantial in recent decades. HIV-related deaths have decreased by 54% since 2010, and new infections have dropped by 40% since that time. This improvement reflects expanded access to testing, treatment, and prevention services worldwide.

The global community has set ambitious targets known as the 95-95-95 goals: by 2025, 95% of people living with HIV should know their status, 95% of those diagnosed should receive treatment, and 95% of those on treatment should achieve viral suppression. In 2024, these figures stood at 87%, 89%, and 94% respectively, showing both progress and the work still needed.

Prevention strategies that work 🔗

Multiple effective prevention methods are now available. Consistent and correct condom use during sex significantly reduces transmission risk. Pre-exposure prophylaxis (PrEP) allows HIV-negative people at high risk to take medication that prevents infection. Post-exposure prophylaxis (PEP) provides emergency medication within 72 hours after potential exposure.

For people who inject drugs, using sterile needles and syringes every time and never sharing injection equipment is critical. Harm reduction programs that provide clean needles and drug treatment services have proven effective in reducing HIV transmission.

Perhaps most importantly, people living with HIV who take their medications as prescribed and maintain an undetectable viral load protect their sexual partners from infection. This makes treatment itself a powerful prevention tool.

Looking toward the future 🔗

Research continues on multiple fronts. Scientists are developing long-acting injectable medications that could replace daily pills, making treatment more convenient. New prevention options, including long-acting injectables and vaginal rings, offer more choices for people at risk. While a cure remains elusive, advances in gene therapy and immune system modification show promise.

The fight against HIV requires more than medical advances. Addressing stigma, ensuring equitable access to healthcare, and supporting vulnerable populations remain essential. Education, testing, and treatment must reach everyone who needs them, regardless of geography, economic status, or social circumstances.

What do you think? How can healthcare professionals better support early HIV testing and treatment adherence in their communities? What role does reducing stigma play in ending the HIV epidemic?

References

1. https://clinicalinfo.hiv.gov/en/glossary/retrovirus
2. https://www.cdc.gov/hiv/about/index.html
3. https://www.who.int/news-room/fact-sheets/detail/hiv-aids
4. https://www.who.int/teams/global-hiv-hepatitis-and-stis-programmes/hiv/prevention/mother-to-child-transmission-of-hiv
5. https://hivinfo.nih.gov/understanding-hiv/fact-sheets/preventing-perinatal-transmission-hiv-during-pregnancy-and-childbirth