HIV/AIDS Johns Flashcards
What is HIV and how was it discovered?
- Etiologic agent of Acquired Immunodeficiency Syndrome (AIDS)
- Discovered independently by Luc Montagnier of France and Robert Gallo of the US In 1983-84
What are other former names of HIV?
- Human T cel lymphotrophic virus (HTLV-III)
- Lymphadenopathy associated virus (LAV)
- AIDS associated retrovirus (ARV)
How was HIV-2 discovered?
It was discovered in 1986 as an antigenic ally distinct virus endemic in West Africa
How does Viral Replication happen in HIV?
- First step, HIV attaches to susceptible host cell.
- Site of attachment is the CD4 antigen found on a variety of cells:
- –Helper T cells
- –Macrophages
- –Monocytes
- –B cells
- –Microglial brain cells
- –Intestinal cells
- T cells infected later on - After a period of latency lasting up to 10 years, viral replication is triggered and occurs at high rate
- CD4 cell may be destroyed in the process
- Destruction of large numbers of CD4 cause symptoms of HIV to appear
About how long can HIV be latent?
10 years
How is the HIV virus transmitted?
- Sexual transmission, presence of STD increases likelihood of transmission
- Exposure to infected blood or blood products
- Use of contaminated clotting factors by hemophiliacs
- Sharing of contaminated needles (IV drug users)
- Transplantation of infected tissues or organs
- Mother to fetus, perinatal transmission variable, dependent on viral load and mother’s CD4 count
What are the symptoms of Primary HIV Syndrome?
Mononucleosis-like, cold or flu-like symptoms may occur 6 to 12 weeks after infection
- lymphadenopathy
- fever
- rash
- headache
- fatigue
- diarrhea
- sore throat
- neurological manifestations
- no symptoms may be present
What is Primary HIV Syndrome like?
- Symptoms are relatively nonspecific
- HIV antibody tests often negative but becomes positive within 3 to 6 months, this process is known as seroconversion
- Large amount of HIV in the peripheral blood
- Primary HIV can be diagnosed using viral load titer assay or other tests
- Primary HIV syndrome resolves itself and HIV infected person remains asymptomatic for a prolonged period of time, often years.
How long is the ‘window’ period of HIV-1 infection?
About three weeks after primary infection.
When do the primary symptoms appear for HIV-1 infection?
Weeks 2-5
When do the secondary symptoms appear for HIV-1 infection?
Years 6-8
When does the HIV-1 p24 antigen spike?
Between weeks 3-4
When is the HIV viral load spike? Where does it decrease? Where does it increase?
Spike: Between weeks 3-4
Decreases: Week 4-Year 2
Increases: Year 2-10 (forever)
Where do HIV antibodies peak?
Around week 5-6, then they slowly decline over many years
When does HIV proviral DNA get really high?
Around week 3 and it stays around the same level for the rest of the disease
What happens during the Clinical Latency Period?
- HIV continues to reproduce, CD4 count Gradually declines from its normal value of 500-1200
- Once CD4 count drops below 500, HIV infected person at risk for opportunistic infections!!
What diseases are predictive the progression to AIDS?
- Persistent herpes-zoster infections (shingles)
- Oral candidiasis (thrush) - a lot of white in back of throat
- Oral hairy leukoplakia
- Kaposi’s sarcoma (KS)
Why do those with HIV get Oral Hairy Leukoplakia?
Being that HIV reduces immunologic activity, the intraoral environment is a prime target for chronic secondary infections and inflammatory processes, including OHL, which is due to the Epstein-Barr virus under immunosuppressed conditions
What is Kaposi’s sarcoma (KS)?
Kaposi’s sarcoma (shown) is a rare cancer of the blood vessels that is associated with HIV. It manifests as bluish-red oval-shaped patches that may eventually become thickened. Lesions may appear singly or in clusters.
What makes HIV advanced/when is HIV considered AIDS?
When CD4 counts drop below 200 the person is considered to have advanced disease
What is an HIV patient at risk for if preventative mediations are not started?
- Pneumocystis carinii pneumonia (PCP)
- Cryptococcal meningitis
- Toxoplasmosis
What are AIDS patients at risk for if their CD4 count drops below 50?
- Mycobacterium avium
- Cytomeglovirus infections
- Lymphoma
- Dementia
- Most deaths occur with CD4 counts below 50
What are opportunistic infections associated with the respiratory system in HIV patients?
- Pneumocystis Carinii Pneumonia (PCP)
- Tuberculosis (TB)
- Kaposi’s Sarcoma (KS)
What are opportunistic infections associated with the Gastro-intestinal system in HIV patients?
- Cryptosporidiosis
- Candida
- Cytomegalovirus (CMV)
- Isosporiasis
- Kaposi’s Sarcoma
