Acquired Immune Deficiency Syndrome Flashcards
HIV 1
More common type of HIV
HIV 2
Mainly seen in Western Africa, one gene difference that makes HIV 2 less virulent than HIV 1 and less transmitted
HIV transmission
Blood born pathogen
Transmitted via contact with blood
IVDU, blood or blood products (1 in 2 million chances now)
Sexual encounters and from Mother to baby
HIV virus anatomy
HIV has a viral envelope with the gp120 surface protein (specific protein)
Has enzymes used for replication reverse transcriptase, integrase, and protease
All enzymes are in case in a capsid
Target CD4 cells of the immune system
Pathogenesis
HIV gp120 protein binds to CD4 T-helper cells and use as host for replication
Binds to two receptors via CD4 receptor and CXCR4 or CCR5 receptors
After fusion CD4 cell is injected with viral RNA (reverse transcriptase) —> viral DNA
Viral DNA —integrase—> become part of host DNA and uses host for replication
After replication viral RNA buds out via protease and infects more cells
Overall decrease in CD4 cells
CD4 cells
CD4 cells function (t-helper cells)
Main cell which recognizes antigens and triggers the immune response
Leave host susceptible to opportunistic infections
Drug Classes
Nucleoside reverse transcriptase inhibitors
Non-nucleoside reverse transcriptase inhibitors
Protease inhibitors
CCR5 inhibitors
Fusion inhibitors
Integrase inhibitors
HIV vs AIDS
HIV positive is total CD4 count is equal or above 200 and HAS NEVER DROPPED BELOW 200
AIDS is a CD4 count less than 200 at any point in time
-can also have signs of an OI or asymptomatic
HIV screening test for…
HIV antibodies or the HIV p24 antigen
3rd generation immunoassay (HIV EIA) or ELISA w/ western blot
OG test of choice
Assesses for presents of HIV antibodies
Can use urine, saliva or serum (serum most accurate result)
Takes 12 weeks to measure HIV antibodies
After 12 weeks —> very accurate
After EIA is positive a Western blot to confirm
If western blot is negative —> person not HIV positive
Oraquick
EIA only test
Rapid HIV test that can be completed in 20 minutes on whole blood
Used as a screening tool
If positive —> additional testing to confirm DX
4th generation combination immunoassay
Gold standard
Test designed to detect HIV antibodies and P24 antigen
P24 antigen can be detected as early as 10 days post-infection (faster than 3rd gen)
Dx acute HIV infection and minimize window period
If test is positive —> HIV 1/HIV 2 test should be done
If HIV 1/HIV 2 test is negative/indeterminate—> HIV viral load test
Signs of HIV/OI
Thrush
Cervical dysplasia (+ Pap smear)
Cervical carcinoma in situ
Fever greater than 38.5 C (101.3 F)x 1 month
Oral hairy leukoplakia (Epstein-Barr virus) white patchy tongue
Herpes Zoster (shingles)
Immune thrombocytopenia purpura (ITP) red blood spots
Pelvic inflammatory disease (PID) bacterial infection in vagina —> uterus, ovaries etc.
Peripheral neuropathy
Frequent vaginal yeast infections
Kaposi Sarcoma (KS) soft tissue lesions (skin, mouth, lymph, internal organs, mucosa)
And OI
Opportunistic Infections (OI)
Persons with HIV can be susceptible to OI
Usually when CD4 count is less than 200
-PCP pneumocystis jiroveci/carnii pneumonia
-MAC mycobacterium avium complex
-CMV cytomegalovirus
Pneumocystis Jiroveci Pneumonia (PCP)
Organism is consider to be a fungi
PCP has a slow and progressive disease
CC: dyspnea and gradual onset that is progressive and slowly gets worse over weeks
SS: fatigued and will likely experience night sweats, wt loss and poor appetite
CXR: butterfly pattern of infiltrates that extend from the center of the chest
Treatment: Bactrim
Disseminated Mycobacterium Avium Complex (MAC)
Acid fast bacillus and results in a system infection
SS: fevers, night sweats, wt loss, anorexia and lymphadenopathy
Treatment: Clarithromycin and Ethambutol for 6-12 months
Extended treatment because of nature of bacteria
AFB grows slowly because of the thick cell wall
Nutrients and medication have a hard time penetrating its cell wall
Cytomegalovirus (CMV)
Herpes Virus
Person with HIV and low CD4 count typically infects the retina and causes CMV retinitis
—> blindness
Most at risk are people with a CD4 count less than 50
People with a CD4 count less than 50 —> must have regular eye exams
CMV is resistant against medications —> no prevention
HIV complications
Multisystem disease
Affects many body organs over time
AA with HIV are at greatest risk of developing HIV related nephropathy must be monitored closely
Anemia, peripheral neuropathy, lymphoma, HIV dementia, Kaposi Sarcoma, diarrhea, pancytopenia, cardiomegaly and prone to many dermatologic issues.
Pediatric HIV infection
Neonates infected via placenta from mothers
Incidence of infection low considering antiretroviral therapy
Without prenatal treatment neonate will show symptoms within 6 months of life
Life expectancy is typically no more than 3 years
Due to OI development usually within 1st year of life
DX of HIV during post-natal period —> HIV viral load test
Mother’s antibodies to HIV cross the placenta and makes it difficult to DX with regular testing methods
Baby HIV viral load testing
2 weeks and 4 weeks old —> presumptive uninfected
1 and 4 months —>definitive uninfected state
Antiretrovirals —> decrease infant mortality 76%
Antiretroviral therapy complications
—> insulin resistance and dyslipidemia
HIV causes chronic inflammation increased CV disease, CNS problems —> encephalopathy
Loss of developmental milestones, intellectual ability, impaired brain growth —> poor prognostic factor
