HIV and Opportunistic Infections

Question 1

How is the diagnosis of AIDS made

Answer 1

CD4+ count <200 and/or presence of any AIDS-defining conditions

Question 2

What are the highest risk activities associated with HIV transmission

Answer 2

Receptive anal sex >> insertive anal sex > receptive vaginal sex > insertive vaginal sex

Question 3

What is the first HIV test to be positive and at what point is it positive?

Answer 3

HIV RNA PCR/ HIV NAAT/ Viral load

Positive during acute HIV (10-33 days after exposure)

Question 4

What is the 2nd HIV test to be positive

Answer 4

HIV p24 antigen

Usually positive during acute HIV

Question 5

What is the last HIV test to be positive

Answer 5

HIV antibody test

May be negative during acute HIV

Question 6

What is the window period of HIV diagnosis

Answer 6

Period in early HIV infection before HIV antibody tests become positive

Question 7

What is the 4th generation HIV test

Answer 7

1. HIV-1/2 antigen/antibody combination immunoassay (p24 antigen + HIV antibody)
2. HIV-1/2 antibody differentiation immunoassay
3. HIV-1 NAT (HIV RNA PCR/ Viral load)

Question 8

What conditions are HIV+ individuals at higher risks for?

Answer 8

Cardiovascular disease (MI, stroke)

Cervical cancer

Question 9

What does U = U mean

Answer 9

Undetectable = Untransmittable

People living with HIV with undetectable levels of virus in blood on treatment cannot transmit HIV through sex

Question 10

What is the timeline for U = U

Answer 10

1- 6 months to become undetectable after starting treatment

6 months to stay undetectable after first undetectable test result

Question 11

What is PrEP

Answer 11

Pre-Exposure Prophylaxis

Medication given to HIV-negative people at risk of HIV to help prevent them from acquiring HIV. Taken daily.

Question 12

Whaat is the most common AIDS-associated opportunitic infection and how does it present

Answer 12

Pneumocycstis Jirovecii Pneumonia

CD4 < 200

Fever, non-productive cough, pleuritic chest pain, dyspnea

Extertional hypoxia

Question 13

How is Pneumocycstis Jirovecii Pneumonia (PJP) diagnosed

Answer 13

Elevated lactate dehydrogenase (LDH)

Analysis of sputum or bronchoalveolar lavage

CT scan shows ground-glass infiltrates

Question 14

How does Mycobacterium tuberculosis present in those with HIV

Answer 14

• CD4 < 500
• Fever, cough, dyspnea, weight loss, night sweats
• X ray shows apical cavitary lesion in upper lung lobes

Question 15

How does TB from Mycobacterium tuberculosis often present in advanced HIV individuals with CD4 < 200

Answer 15

Disemminated disease affecting lungs in milary pattern. Can also affect GI tract, bone, brain and lymph nodes

Question 16

What is the most common HIV associated pulmonary infection

Answer 16

Community aquired pneumonia

Question 17

At what CD4+ count is community acquired pneumonia seen

Answer 17

At any CD4+ count

Question 18

How does community acquired pneumonia present in those with HIV

Answer 18

Fever, cough, SOB, infiltrate on chest x-ray (white cloud)

Question 19

What is the pathophysiology of CNS toxoplasmosis

Answer 19

Reactivation of latent tissue cysts in patients with prior toxoplasma infection

Question 20

At what CD4+ count does CNS Toxoplamosis occur

Answer 20

CD4 < 100

Question 21

What is the usual presentation of CNS Toxoplasmosis & how is it diagnosed?

Answer 21

Presentation: Fever, headache and focal neuro deficits ( seizure, aphasia, hemipareisis)

Diagnosed: MRI finding of multiple ring-enhancing lesions. Brain biopsy needed to definitely diagnose

Question 22

Primary CNS Lymphoma

Answer 22

CD4 < 50

Presentation similar to CNS toxoplasmosis with focal neurologic deficits but MRI shows single ring-enhancing lesions (though may have multiple)

Diagnose: CSF may show malignany lymphoid cells in up to 40% of patients but brain biopsy needed for definite diagnosis

Question 23

What is the leading cause of meningitis in patients with AIDS

Answer 23

Cryptococcal meningitis

Question 24

What is the CD4+ count in those with Cryptococcal meningitis

Answer 24

CD4 < 100

Question 25

What is the presentation of those with Cryptococcal meningitis

Answer 25

Fever, altered mental status, headache, (fever, weigh loss, nigh sweats)

Question 26

How is Cryptococcal meningitis diagnosed

Answer 26

Lumbar puncture with CSF showing elevated opening pressure & positive cryptococcal antigen

Question 27

How does Mycobacterium avium intracellulare (MAI) infection present and how is it diagnosed?

Answer 27

Late complication of AIDS

CD4 < 50 (mean CD4 at diagnosis ~10)

Presents with fever, weight loss, night sweats, abdominal pain, lymphadenopathy

Diagnosied: positive mycobacterial blood culture

Question 28

How does Cytomegalovirus (CMV) infection present with those in AIDS

Answer 28

CD4 < 50

CMV retinitis: Floaters, flashing lights, visual field cut, region of opacified discolored retina

CMV colitis: diarrhea, abdominal pain, weight loss, biopsy w/ classic “owl eyes”

Cyt = sight = see = retinitis

Question 29

How does Candidiasis in HIV present

Answer 29

CD4 < 200

Oropharyngeal candidis: White plaques on an erythematous mucosa that easily scrapes off

Question 30

Oral hairy leukoplakia

Answer 30

Similar to HIV Candidiasis but is EBV associated

White plaques that should not be scraped off

Question 31

What prophylaxus should be given to prevent opportunitsic infections in those with HIV & what pathogens are being prevented

Answer 31

Daily Trimethoprim-sulfamethoxazole (TMP-SMX)

Penumocystis jirovecii (CD4 <200)

Toxoplasmosis (CD4 < 100)

Too Much Prophylaxis - Stop MedX