What type of virus is HIV?
Enveloped, diploid, single-stranded, positive-sense RNA viruses with a DNA intermediate (which is an integrated viral genome (a provirus) that persists within the host-cell DNA)
How does HIV produce cellular immune deficiency?
- Characterized by the depletion of helper T lymphocytes (CD4+ cells)
- The loss of CD4+ cells results in the development of opportunistic infections and neoplastic processes
By the #s - global estimates for adults and children, 2008 vs. 2016
- People living with HIV – 33.4 million vs 36.7 million
- New HIV infections 2.7 million vs 1.8 million
- Deaths due to AIDS 2.0 million vs 1.0 million
Which age bracket contains the largest % of HIV cases?
20-29 y/o make up 37% of HIV cases
Which modes of transmission have the highest % likelihood?
- Mother-infant 15-35% (*~2%)
- Transfusion 80%
Who should get tested for HIV?
- All patients aged 13-64 in all health-care settings*
- HIV screening should be voluntary
- Opt-out screening: patients are notified that testing will be performed unless they decline
- Separate written consent for HIV testing not recommended; general informed consent is sufficient
- Prevention counseling should not be required
- High-risk patients should be screened at least annually
Who is at highest risk for HIV?
- Unprotected sexual intercourse, especially receptive anal intercourse (8-fold higher risk of transmission)
- A large number of sexual partners
- **Prior or current sexually transmitted diseases (STDs):
- Sharing of intravenous drug paraphernalia
- Receipt of blood products (before 1985 in the United States)
- Mucosal contact with infected blood or needle-stick injuries
- Maternal HIV infection (for newborns, infants, and children)
- Gay and bisexual men (including transgender), particularly young African American, are most affected
Which STDs increase risk for HIV?
Gonorrhea and chlamydia infections increase the HIV transmission risk 3-fold, syphilis raises the transmission risk 7-fold, and herpes genitalis raises the transmission risk up to 25-fold during an outbreak
List the ways to reduce HIV risk
- Consistent, correct condom use
- Screening and tx of STIs in individuals at risk for HIV
- Addiction tx for IV drug users and/or participation in needle exchange programs
- In those with high ongoing risk for infection daily pre-exposure prophylaxis with tenofovir-emtricitabine (Truvada)
- If mucosal or parenteral exposure to HIV within the prior 72 hours, post exposure prophylaxis with ART
Which patients should have HIV screening at least annually?
- Injection-drug users (IDUs)
- Sex partners of IDUs
- Persons who exchange sex for money or drugs
- Sex partners of HIV infected
- Men who have sex with men (MSM)
- Heterosexuals who themselves or their sex partners have had >1 sex partner since last HIV test
- Before new sexual relationship
Diagnosis of HIV
-acute or early infection
Combination antigen/antibody immunoassay and HIV viral load (RT-PCR based)
Diagnosis of HIV
-immunoassay/VL results
(-) immunoassay and (-) VL signifies no HIV infection (if recent exposure repeat in 1-2 weeks)
(-) immunoassay and (+) VL suggests an early infection (VL <1000 copies/ml very rarely represents false positive test, repeat!)
(+) immunoassay and (+) VL, early or established infection
What is the next step in the event of (+) immunoassay?
(+) immunoassay needs a second, antibody-only immunoassay (preferably the HIV-1/HIV-2 differentiation immunoassay) if not already performed
What are the 3 phases of HIV/AIDS?
- Primary HIV infection
- Chronic asymptomatic phase
- Advanced AIDS
Etiology of primary HIV infection
- Symptomatic illness in 40-90%
- Illness is nonspecific and mononucleosis-like
- Appears 2-4 weeks after exposure
- Clinical illness lasts 1-4 weeks
List the acute retroviral syndrome symptoms
- Fever
- Lymphadenopathy
- Pharyngitis
- Rash
- Myalgias
- GI complaints
- Encephalopathy
*Ask your patient if at any point since their last HIV (-) test they’ve experienced these symptoms
Describe the rash seen with primary HIV
- Maculopapular rash affecting face, neck, and trunk
- Usually individual lesions < 1cm
- Confluence rare
What lab values will you see with primary HIV?
- Thrombocytopenia
- Leukopenia
- WBCs drop
- Elevated ALT, AST
- Elevated ESR
- ELISA often negative (window period)
Define the chronic asymptomatic phase
Characterized by a long phase of clinical latency (median 10 yrs)
What is happening with viral replication in chronic asymptomatic phase? Where is the virus replicating?
- Viral replication and CD4+ counts are relatively stable
- Virus is actively replicating in lymphoid tissue causing anatomic and functional deterioration
When should we consider our patient to be in category of chronic asymptomatic phase?
If our patient has no signs/symptoms of OIs (opportunistic infections) and last HIV test was 7 years ago she might be in this category
Etiology of advanced AIDS
- Defines the end stage of HIV infection
- Leads to death in 2-3 years in the absence of therapy (opportunistic infections)
- Characterized by high plasma viral load and low CD4+ count
List common opportunistic infections
- PCP pneumonia
- CMV
- Disseminated/ extrapulmonary MAC
- Wasting syndrome
- Invasive cervical cancer
- Kaposi’s sarcoma
What can you tell your patient about her life expectancy?
- HIV is no longer a ‘death sentence’
- Diabetes mellitus can be a useful analogy
- Chronic, incurable disease
- Requires daily medications
