What are the most common questions asked regarding HIV infection and/or AIDS?

Byadmin

January 17, 2025

1. What is HIV, and how is it different from AIDS?

  • Answer:
    • HIV (Human Immunodeficiency Virus) is a virus that attacks the immune system, specifically targeting CD4+ T cells, weakening the body’s ability to fight infections.
    • AIDS (Acquired Immunodeficiency Syndrome) is the most severe stage of HIV infection, where the immune system is significantly weakened, leading to opportunistic infections and certain cancers. Not everyone with HIV develops AIDS if treated effectively.

2. How is HIV transmitted?

  • Answer:HIV is transmitted through contact with specific body fluids from an infected person, such as:
    • Blood
    • Semen and pre-seminal fluids
    • Vaginal fluids
    • Rectal fluids
    • Breast milkCommon transmission routes include:
    • Unprotected sexual intercourse
    • Sharing needles or syringes
    • Mother-to-child transmission during childbirth or breastfeeding
    • Blood transfusions or organ transplants with infected blood (rare in countries with stringent screening).

3. Can HIV be transmitted through casual contact?

  • Answer:No, HIV is not spread through casual contact such as hugging, shaking hands, sharing food or drinks, using the same toilet, or through mosquito bites. It requires the exchange of specific body fluids.

4. What are the early symptoms of HIV infection?

  • Answer:Early symptoms, also known as acute HIV infection, may appear 2-4 weeks after exposure and can include:
    • Fever
    • Fatigue
    • Sore throat
    • Swollen lymph nodes
    • Rash
    • Muscle and joint painSome people may have no symptoms during this stage.

5. How can HIV infection be prevented?

  • Answer:
    • Use condoms consistently and correctly during sexual intercourse.
    • Get tested and know your partner’s HIV status.
    • Use pre-exposure prophylaxis (PrEP) if at high risk of HIV.
    • Avoid sharing needles or syringes.
    • Ensure blood products are screened before transfusion.
    • Pregnant HIV-positive women can take antiretroviral therapy (ART) to prevent mother-to-child transmission.

6. Can HIV be cured? And Why is HIV difficult to treat?

a) Can HIV Be Cured?

  • Answer:There is currently no cure for HIV. However, antiretroviral therapy (ART) can effectively manage the virus, suppress its replication, and allow people with HIV to live long and healthy lives. Although currently, there is no universal cure for HIV, but significant progress has been made. While a functional cure (long-term control of the virus without therapy) has been achieved in a few rare cases, most treatments focus on controlling the virus rather than eliminating it.

Exceptions:
A few people, like the “Berlin Patient” and “London Patient,” were effectively cured after receiving bone marrow transplants from donors with a CCR5-Δ32 mutation. However, these cases are rare and not practical as a widespread treatment due to the risks and complexities involved.

b) Why Is HIV Difficult to Treat?

HIV is challenging to cure for several reasons related to its biology and interaction with the human immune system:

i. Integration into Host DNA

  • HIV integrates its genetic material into the DNA of infected host cells (primarily CD4+ T cells). This means the virus becomes a permanent part of the host cell’s genome, making it difficult to eliminate without destroying the host cells.

ii. Latent Reservoirs

  • After infection, HIV can establish latent reservoirs in long-lived cells (e.g., memory T cells). In these cells, the virus remains dormant and is not actively replicating, making it invisible to both the immune system and antiretroviral drugs.
  • These reservoirs can “reactivate” at any time, allowing the virus to restart replication if treatment is stopped.

iii. High Mutation Rate

  • HIV has an extremely high mutation rate due to its error-prone reverse transcriptase enzyme. This allows the virus to rapidly evolve and develop resistance to antiretroviral drugs and immune responses.

iv. Hiding from the Immune System

  • HIV attacks and destroys the very cells (CD4+ T cells) that are central to orchestrating immune responses, weakening the body’s ability to fight the virus.
  • It also cloaks itself with the host’s cellular components, reducing its visibility to the immune system.

v. Diverse Viral Strains

  • HIV exists as many genetically diverse strains (quasispecies) within the same individual, making it harder to develop treatments or vaccines that target all variants.

vi. Immune System Exhaustion

  • Chronic HIV infection leads to immune exhaustion, where the immune system becomes less effective over time. This makes it harder for the body to mount a strong defense against the virus.

vii. Challenges with Bone Marrow Transplants

  • While bone marrow transplants have cured a few individuals, this approach is impractical for widespread use due to the risks of graft-versus-host disease, difficulty in finding suitable donors, and the invasive nature of the procedure.

Current Treatment Strategies

  • Antiretroviral Therapy (ART):
    • ART is the mainstay treatment for HIV. It suppresses viral replication, allowing the immune system to recover and preventing disease progression.
    • It does not eradicate the virus but reduces viral load to undetectable levels, which also prevents transmission.
  • Functional Cure Research:
    • Efforts are ongoing to achieve a functional cure by targeting latent reservoirs, boosting the immune response, or using gene-editing techniques like CRISPR to remove HIV from infected cells.

c) Why Is a Cure Still Possible?

Despite these challenges, ongoing research has made breakthroughs that suggest a cure might be achievable in the future, including:

  • Gene-editing tools to delete the virus or modify host genes (e.g., CCR5).
  • Immunotherapy approaches to “wake up” and eliminate latent reservoirs.
  • Novel drugs targeting specific steps in the viral lifecycle.

7. How is HIV diagnosed?

  • Answer:HIV is diagnosed through blood or oral fluid tests, including:
    • Antibody tests: Detect antibodies the body makes against HIV.
    • Antigen/antibody tests: Detect both the virus and the antibodies.
    • Nucleic acid tests (NATs): Detect the virus’s genetic material and are used for early detection.

8. What is the life expectancy of someone living with HIV?

  • Answer:With effective ART, people with HIV can live nearly as long as those without the virus. Early diagnosis and consistent treatment are critical for better outcomes.
  • Studies show:
    • With Effective ART: A person diagnosed at age 20 and treated effectively can expect to live into their 70s or beyond, similar to the general population.
    • Without ART: Untreated HIV progresses to AIDS, and life expectancy is significantly shortened, often to 1-3 years after the onset of AIDS.

Key Takeaway

HIV is no longer a death sentence. With early diagnosis, adherence to ART, and proper medical care, people living with HIV can enjoy long, fulfilling lives. Regular check-ups and a healthy lifestyle further improve outcomes.


9. Can a mother with HIV have a healthy baby?

  • Answer:Yes. a mother with HIV can have a healthy, HIV-negative baby with proper medical care and precautions, including ART during pregnancy and delivery, the risk of mother-to-child transmission can be reduced to less than 1%. Advances in antiretroviral therapy (ART) and strategies to prevent mother-to-child transmission (MTCT) have made this highly achievable.
  • How to Prevent Transmission to the Baby
    1. Start Antiretroviral Therapy (ART) Early
      • The mother should take ART throughout pregnancy, labor, and delivery. ART reduces the viral load to undetectable levels, significantly lowering the risk of transmitting HIV to the baby.
      • ART should ideally begin before conception or as soon as pregnancy is confirmed.
    2. Care During Delivery
      • The method of delivery (vaginal or cesarean) is determined based on the mother’s viral load:
        • Undetectable viral load: Vaginal delivery is generally safe.
        • Detectable viral load: A planned cesarean delivery may be recommended to reduce the risk of transmission.
    3. ART for the Baby
      • After birth, the baby is given ART (usually in syrup form) for 4-6 weeks to further reduce the risk of infection.
    4. Avoid Breastfeeding (if recommended)
      • In some regions, especially where safe alternatives to breastfeeding are available, HIV-positive mothers are advised to use formula instead of breastfeeding to eliminate the risk of transmission through breast milk.
      • In low-resource settings where formula feeding may be unsafe, exclusive breastfeeding combined with ART for the mother and/or baby is recommended.
    5. Regular Monitoring
      • Both the mother and baby should be regularly monitored, including:
        • HIV testing for the baby at multiple intervals (e.g., birth, 6 weeks, and 12 months).
        • Monitoring the mother’s viral load during pregnancy and after delivery.

Success Rates

  • With effective ART and adherence to prevention measures, the risk of transmission can be reduced to less than 1%.
  • Without treatment, the risk of MTCT is significantly higher (15-45%).

Key Takeaway

With proper medical care, adherence to ART, and appropriate delivery and feeding practices, HIV-positive mothers can have healthy, HIV-negative babies. Early and consistent medical intervention is critical for the best outcomes.


10. How does HIV affect the immune system?

  • Answer:HIV infects and destroys CD4+ T cells, which are crucial for immune defense. As the number of CD4+ T cells declines, the body becomes more vulnerable to opportunistic infections and diseases.

11. What is ART, and how does it work?

  • Answer:ART (Antiretroviral Therapy) is a combination of medications that suppress HIV replication in the body. It helps maintain a low viral load, preserves immune function, and reduces the risk of HIV transmission.

12. What does it mean to have an undetectable viral load?

  • Answer:An undetectable viral load means that the amount of HIV in the blood is so low that it cannot be detected by standard tests. This is achieved through consistent ART use and indicates effective treatment. People with an undetectable viral load cannot transmit HIV to others through sexual contact.

13. Can someone get HIV from oral sex?

  • Answer:The risk of acquiring HIV from oral sex is very low but not zero. The risk increases if there are open sores, bleeding gums, or other sexually transmitted infections (STIs) present.

14. Can HIV-positive people have relationships with HIV-negative people?

  • Answer:Yes, this is referred to as a serodiscordant or mixed-status relationship. The risk of transmission can be minimized with ART, PrEP, and safe sexual practices.

15. What is PEP, and when should it be used?

What is PEP?

PEP (Post-Exposure Prophylaxis) is a short-term emergency treatment started within 72 hours of potential HIV exposure to prevent infection. It involves taking antiretroviral drugs for 28 days to prevent HIV infection after potential exposure to the virus. PEP is most effective when started promptly and is not a substitute for regular prevention methods like condoms or PrEP (Pre-Exposure Prophylaxis).

When Should PEP Be Used?

PEP should be used in the following situations:

1. Occupational Exposure

  • Healthcare workers or others exposed to HIV-contaminated blood or body fluids through needlestick injuries or mucous membrane exposure.

2. Non-Occupational Exposure

  • Unprotected sexual intercourse with a person who is HIV-positive or whose HIV status is unknown.
  • Sharing needles, syringes, or other injecting equipment.
  • Sexual assault survivors exposed to a risk of HIV.

3. Other High-Risk Situations

  • Any other accidental exposure to blood or body fluids that might carry HIV.

Key Takeaway

PEP is an emergency tool to prevent HIV infection after potential exposure. It must be started promptly (within 72 hours), taken consistently for 28 days, and accompanied by follow-up care. If you think you might need PEP, seek medical attention immediately.


16. Are there individuals who are resistant to HIV? Why?

Yes, some individuals are resistant to HIV infection. This resistance is mainly due to genetic factors, specifically mutations in genes that affect how HIV enters human cells. The most well-known example involves the CCR5 gene, which encodes a protein used by HIV to infect immune cells.

 

Key Factors Behind HIV Resistance

a) CCR5-Δ32 Mutation

  • What is it?
    This is a specific mutation in the CCR5 gene, where 32 base pairs are deleted (hence “Δ32”).

    • Individuals with two copies (homozygous) of this mutation do not produce functional CCR5 protein on their cells, making them highly resistant to HIV strains that use CCR5 to enter cells.
    • Individuals with one copy (heterozygous) produce less CCR5 protein, leading to delayed disease progression if they become infected.
  • Why does this mutation confer resistance?
    HIV uses the CCR5 receptor as a “doorway” to enter CD4+ T cells. Without functional CCR5 receptors, HIV cannot efficiently infect the cells.
  • How common is the CCR5-Δ32 mutation?
    The mutation is most common in people of European descent, with about 1% being homozygous and 10-15% being heterozygous. It is rare in other populations.

b) CXCR4-Using HIV Strains

  • Some HIV strains use a different receptor, CXCR4, instead of CCR5 to infect cells. People with the CCR5-Δ32 mutation are not resistant to these strains, although CXCR4-using strains are less common in the early stages of infection.

c) HLA Variants

  • Certain variants of HLA (Human Leukocyte Antigen) genes, which regulate immune responses, are associated with slower progression of HIV infection. For example:
    • HLA-B*57 and HLA-B*27 are linked to better control of HIV replication and delayed disease progression.

c) Innate Immune Factors

  • TRIM5α Protein: In some primates, this protein blocks HIV replication. While less effective in humans, variations in the TRIM5α gene may influence susceptibility.
  • APOBEC3G Enzyme: This enzyme interferes with HIV replication by inducing mutations in the virus’s genome. HIV counters this with a protein called Vif, but variations in APOBEC3G may still impact resistance.

Why Did the CCR5-Δ32 Mutation Evolve?

The exact reason is unclear, but it is hypothesized that the mutation may have provided protection against other historical diseases, such as the bubonic plague or smallpox, which exerted strong selective pressure on populations in Europe.

 

Implications for HIV Treatment and Prevention

  • The discovery of the CCR5-Δ32 mutation has inspired treatments like CCR5 inhibitors (e.g., Maraviroc), which block the CCR5 receptor to prevent HIV entry.
  • Gene-editing technologies like CRISPR-Cas9 are being explored to mimic the effects of the CCR5-Δ32 mutation in people without it.

Why can Anopheles mosquitoes transmit malaria but not HIV/AIDS?

    • disease progression.

17. Why can Anopheles mosquitoes transmit malaria but not HIV/AIDS?

Anopheles mosquitoes can transmit malaria but not HIV/AIDS due to several biological and physiological factors related to the mosquito, the malaria parasite, and the HIV virus:

a) Suitability of the Mosquito as a Host

  • Malaria parasite (Plasmodium): Anopheles mosquitoes serve as both a biological host and a vector for the Plasmodium parasite. The parasite undergoes part of its lifecycle in the mosquito’s midgut and salivary glands, enabling transmission to humans when the mosquito feeds.
  • HIV: The mosquito is not a suitable host for the HIV virus. HIV cannot replicate within the mosquito’s body, as the virus requires specific host cells (human CD4+ T cells) to multiply. Mosquitoes lack these cells.

b) HIV Digestion in the Mosquito Gut

When a mosquito feeds on the blood of an HIV-positive individual, the virus is ingested into the mosquito’s gut. However, the digestive enzymes in the mosquito’s stomach quickly destroy the virus, preventing it from surviving or replicating.

c) No Transmission Pathway

Malaria parasites develop in the mosquito’s salivary glands, making them transmissible when the mosquito bites another host. In contrast:

  • HIV remains in the mosquito’s gut and does not reach the salivary glands.
  • A mosquito does not inject blood from a previous host into a new host during feeding. It injects saliva, which contains anticoagulants, but not blood or viruses like HIV.

d) HIV Concentration and Survival

  • HIV concentrations in human blood are typically low compared to the number of parasites involved in malaria transmission.
  • Even if an HIV-infected mosquito were to bite another person, the amount of virus potentially transferred would be too small to establish an infection.

e) Lifecycle Compatibility

  • The lifecycle of Plasmodium parasites is well-adapted to the mosquito as an intermediate host, requiring both the mosquito and human hosts to complete its cycle.
  • HIV does not have any stage of its lifecycle that can occur in a mosquito.

In summary, Anopheles mosquitoes are specialized vectors for malaria due to the compatibility of their biology with the Plasmodium lifecycle. However, they cannot transmit HIV because the virus cannot replicate, survive, or reach transmissible levels within the mosquito.


 

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