HIV Disease Stages and Classification

HIV Disease Stages and Progression

• HIV disease progresses through stages, from acute infection to death.
• Without treatment, the time from infection to death is approximately 12 years.
• In resource-limited countries, this time is about 5 years.
• Comorbidities like malnutrition, TB, and malaria shorten survival time.

History of HIV/AIDS Recognition

• June 1981: CDC reported the first cases of PCP in gay men, leading to the term AIDS.
• 1985: Antibody test for HIV became available, revealing HIV infection without AIDS symptoms.
• 1986: CDC created a disease classification system based on HIV infection stages.
• Stages include acute, asymptomatic, symptomatic HIV infection, and AIDS.

Current HIV Classification

• Adults are categorized into three stages based on:
  • CD4+ lymphocyte count.
  • CD4+ percentage of total lymphocytes.
  • Presence/absence of AIDS-defining conditions.
• If an individual has an AIDS-defining condition, they have AIDS, regardless of their CD4+ count.
• Infant/child classifications differ from adult classifications.
• Severity progression is one-way; reclassification to a less severe stage isn't possible.

Global HIV Statistics (2020)

• Approximately 37.7 million people globally were living with HIV.
• Approximately 1.5 million new HIV infections occurred.
• 680,000 deaths related to HIV occurred.

HIV Epidemiology in the U.S. (2016 & 2019)

• Approximately 2 million adults/children infected since the epidemic's start, and 600,000 fatalities.
• 1.1 million Americans currently live with HIV.
• 15% unaware of their infection.
• 2019 gay men had the highest rate of new infections (66%).
• African Americans are the most affected racial/ethnic group.
• New infections decreased by 8% from 2015-2019.
• District of Columbia, Georgia, and Florida have the highest HIV incidence currently.

HIV Transmission

• Primarily a sexually transmitted disease, but also transmitted through:
  • Injection drug use (sharing equipment).
  • Blood transfusions (rare).
  • Occupational exposure (rare).
  • Pregnancy and breastfeeding.

HIV Pathophysiology

• HIV compromises immune system functions (targeting CD4+ cells).
• Chronic destruction of CD4+ cells due to HIV replication.
• CD4+ cells (T helper cells) release cytokines to fight infections.
• HIV targets, disables, and destroys CD4+ cells.
• Untreated HIV infection leads to opportunistic infections (OIs).

Opportunistic Infections (OIs)

• Infections like TB, toxoplasmosis, candidiasis, PCP, CMV, HSV, histoplasmosis, Kaposi’s sarcoma, MAC, etc., are more severe in people with weakened immune systems.
• These pathogens exploit the weakened immune system.

HIV Viral Replication

• Acute viral infection:
  • Inflammatory reaction upon infection.
  • Virus enters CD4+ cell, converting RNA to DNA.
  • Viral DNA integrates into host DNA.
  • New viral proteins are assembled and released, destroying the CD4+ cell.
  • Rapid decrease in CD4+ lymphocytes and increase in viral load.
  • Flu-like symptoms may occur, followed by antibody development (seroconversion).

Asymptomatic Chronic Infection

• Immune system controls viral replication, but not elimination.
• CD4+ count rises to near normal, viral load decreases.
• Viral replication and CD4+ cell loss both continue slowly.

Symptomatic Chronic Infection

• Reduced immune control of viral replication as CD4+ count declines.
• Symptoms develop due to impaired immunity.
• Respiratory infections, skin problems, lymphadenopathy, weight loss.
• CD4+ declines rapidly, viral load increases.
• Average time to AIDS once symptomatic: 2 years.

Acquired Immune Deficiency Syndrome (AIDS)

• Declining CD4+ count results in a severely weakened immune system.
• Infections become harder to control, may reactivate.
• AIDS occurs when a person has a CD4+ count less than 200 cells/mcL and/or AIDS-defining illnesses.

Clinical Manifestations (HIV/AIDS)

• Common signs/symptoms: fever, cough, weakness, nausea/vomiting, diarrhea, difficulty swallowing, forgetfulness, skin lesions, shortness of breath, headache, vision changes, pain, night sweats, swollen lymph nodes.
• Urgent attention required for: new cough, increased fatigue, temperature over 102°F, night sweats, new headaches/vision changes/mental status problems, new skin lesions, new diarrhea, weight loss of over 10%.

Interprofessional Management

- **Medical Management:**  Diagnostic testing, prophylaxis, and antiretroviral therapy (ART).
- **Diagnostic Testing:** 
    - Annual HIV screening for adolescents and adults (15–65).  Higher-risk individuals may need more frequent testing (every 3 months).
    - Pregnant person screening.
    -  Screening for HIV antibodies (rapid tests, ELISA/EIA, Western Blot, PCR). 
    -  Genotype, viral load, and CD4+ testing.
    -  Co-infection screening (TB, other STIs).
- **Prophylaxis:** Treating OIs (e.g., toxoplasmosis, PCP) if CD4+ count is low. The prophylaxis can be discontinued as the immune count improves.
- **Antiretroviral Therapy (ART):** Suppressing viral load through lifelong medication adherence; initiating ART is recommended for all HIV-positive people.
- **Treatment Preparation:** Explaining advantages/disadvantages of therapy, explaining the necessity of lifelong adherence to treatment, why a certain combination of medications was selected, how and when to take medications, side effects, reducing potential side effects, and the effect of medications on the immune system.

Immunizations

• Vaccination maintenance is essential for PLWH.
  • Vaccines recommended for PLWH: Tdap, Streptococcus pneumoniae, seasonal influenza, hepatitis A/B, meningococcal, HPV, zoster,
• Specific recommendations for pneumococcal vaccines: PCV13 and then PPSV23, with PPSV23 given every 5 years.
• Influenza vaccine annually.
  • Tetanus, diphtheria, and pertussis every 10 years.
  • Herpes zoster RV using non-live recombinant vaccine at age 50 (CD4+ over 200).

Prevention

• Routine HIV testing (opt-out) for adults (15–65).
• Annual testing for high-risk individuals.
• ART for PLWH reduces transmission.
• Maintaining viral suppression is key in the cascade of care to reduce transmission.

Explore the various stages and progression of HIV disease from acute infection to AIDS. This quiz covers the historical recognition of HIV/AIDS, the development of classification systems, and current criteria based on CD4 counts and conditions. Test your knowledge on this significant topic in public health.