HIV SG Flashcards
When was AIDS first published
1981
What is HIV
a retrovirus; uses reverse transcriptase to turn RNS into DNA, integrate it’s genetic material into host DNA, and new virus is produced
What does HIV target
T cells (esp CD4 helper cells) Also, B lymphocytes and macrophages
What do lymphocytes do
WBC that defend against VIRUSES, fungi, some bacteria, and protozoa
What are B and T cells
- B cells make Abs to attack antigens
- CD4 T cells enhance immune response and tell B cells to make Abs
- CD8 killer cells destroy foreign agents
How does HIV replication occur
HIV particle fuses to CD4 component HIV incorporated into host cell by reverse transcriptase New copies of HIV released
How is HIV transmitted
Sexually: exchange of body fluids IVDU Needlestick injuries (occupational) Blood products (extremely low risk now) HIV infected mom to infant -Basically, requires infectious body fluid and portal of entry! Not spread via casual contact!
What is the risk of transmission
Insertive vaginal sex: 1/10K Receptive vaginal sex: 1/1K Needle stick: 1/300 Shared drug needle: 1/150 Receptive anal: 1/50
What is acute HIV
2-6 weeks after exposure, HIV initiates the attack and CD4 cells drop rapidly You develop mono or flu-like Sx that ;ast about 2 weeks, then resolve (this indicates your body initially fighting back at the disease) Patient is highly infectious
What do labs show in acute HIV
HIV antibody test is usually negative! it is too early for your body to have developed antibodies HIV RNA (viral load) is measurable, and extremely high (>100K) -Providers often only order the Ab test, which comes back negative, they tell the pt they are negative, and then they go infect others. -Elevated LFT’s, Leukopenia, anemia, thrombocytopenia
What does catching acute HIV allow
To stop the spread of disease to others But, once you have HIV, you can’t stop the disease progression
What are common manifestations of acute HIV
Fever adenopathy sore throat rash* upper trunk, neck, face Mucocutaneous ulcers myalgias arthralgias HA diarrhea N/V
What is clinical latency
It begins as immune system responds to infection (acute illness resolves)- lasts appx 10 years Patient seroconverts (serum becomes HIV antibody +) around 3 months after infection Viral load decreases to a set point and slowly rises over time (HIV is active in lymph nodes this whole time) CD4 slowly declines Patient is ASx usually
What happens during a symptomatic infection
Lymph nodes and tissue are damaged (burnt out) Virus may mutate and be more pathogenic Body fails to keep up with replacement of CD4 cells Viral load (HIV RNA) increases CD4 count decreases
What are HIV Sx
fever, night sweats LAD fatigue, malaise arthralgias weight loss *Hairy leukoplakia prolonged diarrhea cervical dysplasia (HPV) Molluscum, dermatophyte infection, seborrheic dermatitis *Kaposi Sarcoma recurrent HZV ITP
What is a normal CD4 count
600-1200 (then she says 500-1400)
What is usually the first Sx of HIV
Tuberculosis! immune system fails revealing TB Sx
What is AIDS
CD4 count <200 OR HIV + 1 of 27 AIDS defining conditions
What occurs at different CD4 counts
<200: P. jiroveci PNA, <100: Toxoplasmosis <50: MAC, CMV Any: Kaposi, Candida
What is pneumocystic jiroveci pneumonia
airborne fungus that reactivates when CD4 count is <200 Common opportunistic infx associated w/ AIDS Presents w/ nonspecific Sx (fever, cough, SOB) =/- hypoxemia CXR shows diffuse perihilar infiltrates
How do you diagnose and treat P. jirovecii PNA
Sputum sample; can also get LDH (elevated) Tx: Bactrim DS*** and supportive care
What is Toxoplasmosis
Parasite (toxoplasma gondii) that reactivates when CD4 <100 Causes encephalitis, IC lesions Acquired via cat feces, contaminated raw food or utensils If immunocompetent, you rarely show Sx
How does toxoplasmosis present in HIV
HA FND seizures AMS Retinitis Pneumonitis
How do you diagnose Toxoplasmosis
CT/MRI will show contrast enhancing lesions on brain Seropositive for toxoplasmosis
What is MAC
Mycobacterium avium/intracellulare, found in soil and dust, is inhaled or ingested Can cause pulmonary infections in immunocompetent In AIDS, can cause systemic disease, night sweats, weight loss, abdominal pain, diarrhea, anemia
How do you diagnose MAC
Sputum acid fast bacillus (+) Positive sputum sultures Positive blood cultures
What is CMV retinitis
MC retinal infections in AIDS! herpes virus (CMV) transmitted by blood, sex, or perinatally, causes visual disturbances that may lead to blindness
How do you diagnose CMV retinitis
Perivascular hemorrhages and white fluffy exudates on fundoscope (cotton wool spots, infiltrates, and hemorrhages) Seropositive (+ Abs) for CMV
How is CD count related to candidiasis
The more invasive the esophageal or vaginal candidiasis, the lower the CD4 count
What is Kaposi’s sarcoma
Vascular neoplasm that can occur at any T cell count MC in older eastern european and mediterranean males MC in homosexual men Lesions are multifocal and widespread, w/ associated LAD
How do you treat Kaposi sarcoma
Many Tx available, like Thalidomide (teratogen that causes short limbs)
HIV is…
a CHRONIC disease, not a terminal disease!
Who should be screened for HIV at LEAST once
everyone 13-64 (can opt out) anyone who is starting TB Tx At each STD presentation Annually for at risk patients (MSM) Pregnant women -Not providers, because we generally can not transmit HIV to our patients
Who should get more frequnt HIV testing
Opportunistic infections TB Sx of established HIV: weight loss, fever, tiredness, LAD, diarrhea >1 week, sores of mouth, anus, genitals, PNA, unexplained neuro Sx Sx associated w/ acute HIV
What is the HIV antibody test
Detects the antibody our bodies make 4-12 weeks after infection, after patient seroconverts
What is a rapid HIV test
another HIV antibody test done by saliva or blood If positive, you need a confirmation test Will not show positive if acute HIV
What is preferred testing for HIV
Combination HIV antibody&antigen testing! WILL detect acute HIV (viral load will be high)
If a combination HIV Ab/Ag test comes back positive…
Must differentiate between HIV 1 & 2 thru the differentiation immunoassay (In US, MC is: HIV1 +, HIV2 -)
What is your pt has no insurance/is very young
Maricopa county STD clinic: $20 but, only the rapid test is available Minors can get STD testing w/o parents, but HIV is not explicitly included. Send minors to county
What treatment is recommended in ALL HIV patients (esp. acute/early infection)
Antiretroviral Therapy (ART) The earlier you treat, the more immunologic and virologic benefits you experience
If you diagnose someone with HIV, how do you proceed
Call the HIV clinic, set up an appointment for the NEXT DAY Get them on Tx ASAP!
How do you select ART
Based on genotypic drug resistance preformed at referral
How long do you treat HIV
Lifelong! they must be willing to commit They can postpone Tx if they will not be compliant and CD4 is higher, around 400ish, because being non-compliant is dangerous. it can lead to resistance
What are Tx goals for HIV
Suppress plasma HIV RNA levels to undetectable
Possible HIV exposures include
Unprotected sex Condom broke or fell off Rape or sexual assault Work related injury Sharing needles for drugs
What is post-exposure prophylaxis
Reduces risk of you acquiring HIV once you have been exposed! MUST start within 72 hours of exposure
What is pre-exposure prophylaxis
Daily medication (Truvada) that may be prescribed by HIV specialist or PCP
What Sx do you see at different CD4 levels
Normal (500-1400): thrush, Kaposi sarcoma (people do well usually if 350+) 200: opportunistic infections <200= AIDS (or any CD4 with a opportunistic AIDS infx)
What meds do you give to patients based on CD4 counts
<200: Bactrim (prophylaxis for PJP) <100: Bactrim (prophylaxis for toxoplasma) CD4 <50: Azithromycin (prophylaxis for MAC)
- Is the incidence of HIV increasing or decreasing?
- Which sex has higher rates?
- What age group has highest rates of NEW infection?
- Increasing slightly
- Men
- 20-29
- Which 2 races are “disporportionately affected” by HIV?
- Which 3 categories of people are at highest risk?
- African Americans
- Hispanic/Latino
- Male to Male sex
- Heterosexual sex
- IV drug use
- What are the 2 types of HIV and which one is MC in the United States?
- Which is MC in West Africa?
- HIV 1: US
- HIV 2: Africa
