Virology B1: Presentation And Diagnosis Of Hiv Infection

Front 1

1) What mode of transmission has the highest risk of HIV infection?
2) Lowest?
3) Prolonged breast feeding can account for what % of new infant cases worldwide?
4) What is infection highly correlated with?

Back 1

1) Blood transfusion
2) Oral intercourse
3) 40%
4) HIV RNA plasma levels of source patient

Front 2

1) Is the oral cavity a common site of HIV transmission?
2) What prevents transmission?

Back 2

1) NO
2a) Low concentrations of infectious virus
2b) Endogenous salivary anti-HIV facotrs like mucins, thrombospondins, PrP, lactoferrin, salivary agglutinin
2c) Hypotonicity of saliva
2d) Antibodies to HIV found in saliva (IgG>IgA), origin of IgG unclear

Front 3

1) 5-10 days post infectious virus, what two factors are detectable?
2) When does this factor's concentration peak? When is it detectable until?
3) What can happen 10-20 days post infection?

Back 3

1) Viral mRNA and soluble p24.
2) p24 (gag) concentration peaks 10-20 days post infection, remains detectable until seroconversion
3) Some individuals can eliminate infection

Front 4

How might the following factors influence infection:

1) Host genetics (HLA B27, B57) HLA allele concordance, CCR5 mutation)
2) Mucosal exposure to low viral dose
3) Infection with less pathogenic strain
4) Vaginal colonization with lactobacillus
4) Other

Back 4

1) HLA B27 and B57 associated with low viral load, prolonged asymtomatic phase. HLA allele concordance may increase risk of transmission, CCR5 mutation can resist infection.

2) Mucosal exposure to low viral dose associated with resistance

3) Infection with less pathogenic strain associated with long-term survival

4) Significantly reduces cervicovaginal HIV viral load

Front 5

CCR5delta32:

1) Who carries it?
2) Where is the mutation absent?
3) What is heterozygosity associated with?
4) Is abscence of CCR5 tolerated? Reduced risk and increased risk of what diseases?
5) How big is the deletion?

Back 5

1) 5-10% of European whites
2) Africa, East Asia
3) Slow progression of HIV
4) Yes - resists infection with R5 strain, reduces RhA, increased severe West Nile infection
5) 32bp deletion

Front 6

What are the five clinical stages of HIV infection?

Back 6

1) Acute retroviral infection - mono like syndrome

2) Asymptomatic - except lymphadenopathy (follicular hyperplasia)

3) Early symptomatic - non life-threatening situations

4) Late symptomatic - increasingly severe infections, life threatening, malignancies

5) Advanced - high frequency of opportunistic infections, high mortality risk

Front 7

Acute HIV infection:

1) What is the incubation time?
2) What % of patients will be symptomatic?
3) Symptoms?
4) Patient progress from initial symptoms?

Back 7

1) 2-4 weeks
2) 40-90%
3) Mono-like symptoms - fever, pharyngitis, myalgias, headache, nausea, diarrhea, maculopapular rash, **ORAL ULCERS** (painful, superficial ulcers)
4) Most patients recover completely from initial symptoms

Front 8

Asymptomatic HIV infection:

1) Manifestations?
2) How long does it last?
3) What should patient be monitored for?
4) What other diseases should they be evaluated for?
5) Women should receive?
6) Vaccines? What vaccines are contraindicted?

Back 8

1) Seropositive, lymphadenopathy
2) 10 years on average
3) Viral load, CD4+ T cell numbers
4) **Syphilis, TB, HBV**
5) Biannual pap smears
6) Where indicated. NO LIVE VACCINES - live attenuated influenza, varicella or zoster if CD4<200 mm^3

Front 9

Early symptomatic infection:

1) Symptoms?
2) What other organism is it associated with?

Back 9

1) Candidiasis (oral, vaginal) - frequent and recurring, diarrhea and weight loss due to **cryptosporidium**, generalized lymphadenopathy, fever, night sweats, fatigue

Front 10

What is another name for HIV?

Back 10

Wasting disease

Front 11

How is weight associated with HIV?

Back 11

Wasting disease, cachexia and stunting in children

Front 12

What are the five main fungal infections seen in AIDS defining conditions in late symptomatic and advanced HIV infection?

Back 12

1) Candidiasis of esophagus, trachea, bronchi or lungs
2) Coccidioidomycosis, extrapulmonary
3) Cryptococcosis, extrapulmonary
4) Histoplasmosis, extrapulmonary
5) Pnuemocystis jirovecii, pneumonia

Front 13

What are the three main viral infections seen in AIDS defining conditions in late symptomatic and advanced HIV infection?

Back 13

1) CMV of any organ other than liver, spleen, lymph nodes

2) Herpes simplex with mucocutaneous ulcer for >1 month or bronchitis, pneumonitis, esophagitis

3) JC virus - progressive multifocal leukoenchalopathy (PML)

Front 14

What are the 4 main bacterial infections seen in AIDS defining conditions in late symptomatic and advanced HIV infection?

Back 14

1) Mycobacterium avium, disseminated
2) Mycobacterium tuberculosis, disseminated or pulmonary
3) Pneumonia, recurrent bacterial with + HIV serology
4) Salmonella septicemia (non-typhoid), recurrent with + HIV serology

Front 15

What are the 2 main parasitic infections seen in AIDS defining conditions in late symptomatic and advanced HIV infection?

Back 15

1) Cryptosporidiosis
2) Isosporosis

Front 16

What are the 4 types of neoplasias seen in AIDS defining conditions in late symptomatic and advanced HIV infection?

Back 16

1) Invasive cervical cancer
2) Kaposi's sarcoma - patient younger than 60 (or older than 60 with + HIV serology)
3) Lymphoma of brain in patient <60, or >60 with + serology
4) Lymphoma, non-Hodgkins

Front 17

What are the three other AIDS defining conditions seen in late symptomatic and advanced HIV infection?

Back 17

HIV associated dementia - interferes with daily activities

HIV associated wasting - involuntary weight loss of >10% of baseline + chronic diarrhea

3) Chronic weakness, documented enigmatic fever or >30 days

Front 18

In primary HIV disease, what 4 things present in the CNS?

Back 18

1) AIDS dementia complex (encephalopathy) - demyelination, deep white matter lesions
2) Vacuolar myelopathy (spinal cord)
3) Peripheral neuropathy
4) Meningitis (acute/chronic)

Front 19

HIV is present in the brains of almost all affected individuals. Where is it found?

Back 19

1) Microglial cells/blood derived macrophages (CD4+)
2) Astrocytes, neurons (CD4-?), not sure what receptor is used

Front 20

What is the characteristic of AIDS dementia complex in primary HIV disease?

Back 20

Deep white matter lesions, ** multinucleated macrophage derived giant cells **

Front 21

What are the 4 methods for diagnosis of HIV infection?

Back 21

1) Hx/exam
2) ELISA for HIV antibody
3) Western Blot
4) Viral RNA detection by PCR

Front 22

ELISA for HIV antibody diagnosis for HIV infection

1) How many times do you do it?
2) What antibodies are usually detected first?
3) What antibodies are detected later?

Back 22

1) Screening test, repeat if +, confirm with Western blot
2) gp120, gp41
3) p24

Front 23

1) What is the gold standard of HIV diagnosis?
2) When is it considered positive?

Back 23

1) Western blot (immunoblot)
2) If antibodies to structural proteins, enzymes, envelope proteins detected simultaneously

Front 24

What is the accuracy of the ELISA + Western blot test in diagnosis of HIV infection?

Back 24

>99.5%

Front 25

Viral RNA detection by PCR for diagnosis of HIV infection:

1) What is its advantage?
2) When do you use it?

Back 25

1) Rapid diagnosis
2) Use in babies of infected moms

Front 26

ELISA:

1) What do colored wells mean?
2) How does it work?

Back 26

1) Reactivity
2) HIV coated well, add antibody, add anti-human enzyme conjugate, chromogenic substrate -> color

Front 27

How many weeks does it normally take before HIV antibody appears following exposure?

Back 27

4-6 weeks

Front 28

HIV viral antigen detection, viral load: RT-PCR:

1) When can it be used?
2) Does viral load have a good prognostic value?
3) What is it also used to monitor the response of?
4) Is CD4 cell a good predictor of disease progression?

Back 28

1) Early diagnosis in babies born from HIV + moms
2) Yes
3) Response to antiviral chemotherapy
4) NO

Front 29

CDC recommendations: routine testing for HIV:

Back 29

Routine voluntary testing not based on risk, repeat testing at discretion of provider, based on risk (high risk at least annually, new partner, high risk pregnancy repeat in third trimester)

All persons 13-64, routine prenatal testing, no separate consent required, pretest counseling not required