HIV Flashcards
How is HIV transmitted?
- **Sexual transmission (most common) (6 transmittable fluids: vaginal, anal, pre-ejaculate, ejaculate, blood, breast milk)
- Transfusion of blood and blood products
- Contaminated needles
- MTCT (mother-to-child transmission) -> in-utero, intra-partum, perinatal period, breastfeeding
What are the viral AIDs defining conditions?
- HSV -> chronic ulceration (> 1 month), bronchitis, pneumonitis, oesophagitis
- CMV -> retinitis, disease other than liver/spleen/LNs
- JC virus -> progressive multifocal leukoencephalopathy (PML)
What are the bacterial AIDs defining conditions?
- MTB -> of any site
- MAC or Mycobacterium kansasii -> disseminated/extrapulmonary
- Recurrent bacterial pneumonia (≥ 2 episodes in 1 year)
- Recurrent Salmonella septicaemia (can seed to bone, vasculature)
What are the fungal AIDs defining conditions?
- Candidiasis -> oesophageal, trachea, bronchi, lungs
- Cryptococcosis -> extrapulmonary (e.g. meningitis)
- Histoplasmosis -> extrapulmonary/disseminated
Aspergillosis - Pneumocystis jirovecii pneumonia (PCP)
What are the protozoa AIDs defining conditions?
- Toxoplasma gondii -> cerebral toxoplasmosis
- Cystoisosporiasis -> chronic intestinal (> 1 month)
What are the AIDs defining malignancy?
- Lymphomas -> primary brain, Burkitt (immunodeficiency variant), immunoblastic
- Kaposi’s sarcoma (HHV-8)
- Invasive cervical cancer
What are the AIDS defining conditions seen in the brain?
Mass lesions
- Toxoplasma vs primary CNS lymphoma (PCNSL)
- Cryptococcus
- TB
Diffuse encephalitis (viral, present with altered mental status AMS): CMV, HSV, VZV
What are the AIDS defining conditions seen in the eye?
CMV retinitis (ask for blurring of vision BOV)
What are the AIDS defining conditions seen in the mouth?
Oesophageal candidiasis (oral candidiasis is not considered, because abx therapy can cause it also)
What are the AIDS defining conditions seen in the neck?
Lymphadenopathy
- NTM
- TB
- Disseminated MAC (bacteraemia as well)
- Lymphoma
What are the AIDS defining conditions seen in the lung?
- Recurrent bacterial pneumonia (especially Streptococcus pneumoniae)
- TB
- PCP – life threatening! Also, is the most common opportunistic infection (OI)
- Mycobacterium avium-intracellulare (MAI)
- CMV
- Histoplasmosis, Blastomyces (endemic fungi)
What are the AIDS defining conditions seen in the gut?
- Salmonella enteritidis (recurrent Salmonella bacteraemia)/Salmonellosis
- Cystoisosporiasis, cryptosporidium (ask for chronic diarrhoea)
What are the AIDS defining conditions seen in the genitals?
Invasive cervical cancer
What are the AIDS defining conditions seen in the skin?
- Kaposi sarcoma (HHV8)
- Disseminated herpes zoster (> 2 dermatomes, or non-contiguous, or cross midline)
What are the clinical features of acute retroviral syndrome?
Acute onset (usually fever -> rash -> pharyngitis -> lymphadenopathy)
- Fever, fatigue, myalgia/arthralgia
- Rash (macular/maculopapular rash of face, neck, upper torso)
- Headache, pharyngitis, lymphadenopathy (especially cervical)
- Gastrointestinal -> N&V, diarrhoea
- Mucocutaneous ulcerations -> painful ulcers on oral mucosa, anus, penis, oesophagus
- Neurological -> aseptic meningitis
What are the differentials for acute retroviral syndrome?
- **Infectious mononucleosis (EBV, CMV) -> do heterophile antibody (Monospot) test
- Other viral illness -> e.g. viral hepatitis
- Bacterial -> syphilis, disseminated gonorrhoeal infection
- Autoimmune -> new-onset SLE
How is HIV diagnosed?
Diagnosis of HIV infection is made by detection of circulating antibodies to HIV. Antibodies are identified by the use of a screening test, usually an enzyme-linked immunosorbent assay (ELISA), followed by definitive diagnosis using a Western Blot assay. HIV antibody is detectable in at least 95% of patients within 3 months after infection
In some situations such as pre-seroconversion or neonatal infection, measurement of HIV antibodies may be unreliable. In these instances, diagnosis of infection may use direct detection of HIV itself such as quantification of plasma HIV RNA, HIV viral DNA, or HIV antigen or by detection and amplification of virus in a tissue culture
What are the lab screening needed for HIV patients
HIV specific
- HIV ag/ ab testing- to confirm diagnosis
- CD4 count
- viral load
- genotypic resistance testing for PI, NRTI, NNRTI
- HLA-B*5701 (for abacavir HSR), G6PD
routine/ generatl
- CBC
- chemistry with BUN/ Cr
- AST, ALT, total bilirubin, ALP
- albumin, total protein
- fasting lipids, CBG, HBA1C
- pregnancy test (if applicable)
- CXR
co- infection
- HAV Ab, total or IgG
- HBsAg, HBsAb, HBcAb
- HCV Ab
- Syphilis
- Gonorrhea, chlamydia NAAT
- trichomonas
- LTBI screening
Screen for OI (CMV IgG, Toxoplasma IgG, VZV IgG, screen eye, Cryptococcal antigen if CD4 < 50)
