HIV and Opportunistic Infections Flashcards
How is the diagnosis of AIDS made
CD4+ count <200 and/or presence of any AIDS-defining conditions
What are the highest risk activities associated with HIV transmission
Receptive anal sex >> insertive anal sex > receptive vaginal sex > insertive vaginal sex
What is the first HIV test to be positive and at what point is it positive?
HIV RNA PCR/ HIV NAAT/ Viral load
Positive during acute HIV (10-33 days after exposure)
What is the 2nd HIV test to be positive
HIV p24 antigen
Usually positive during acute HIV
What is the last HIV test to be positive
HIV antibody test
May be negative during acute HIV
What is the window period of HIV diagnosis
Period in early HIV infection before HIV antibody tests become positive
What is the 4th generation HIV test
- HIV-1/2 antigen/antibody combination immunoassay (p24 antigen + HIV antibody)
- HIV-1/2 antibody differentiation immunoassay
- HIV-1 NAT (HIV RNA PCR/ Viral load)
What conditions are HIV+ individuals at higher risks for?
Cardiovascular disease (MI, stroke)
Cervical cancer
What does U = U mean
Undetectable = Untransmittable
People living with HIV with undetectable levels of virus in blood on treatment cannot transmit HIV through sex
What is the timeline for U = U
1- 6 months to become undetectable after starting treatment
6 months to stay undetectable after first undetectable test result
What is PrEP
Pre-Exposure Prophylaxis
Medication given to HIV-negative people at risk of HIV to help prevent them from acquiring HIV. Taken daily.
Whaat is the most common AIDS-associated opportunitic infection and how does it present
Pneumocycstis Jirovecii Pneumonia
CD4 < 200
Fever, non-productive cough, pleuritic chest pain, dyspnea
Extertional hypoxia
How is Pneumocycstis Jirovecii Pneumonia (PJP) diagnosed
Elevated lactate dehydrogenase (LDH)
Analysis of sputum or bronchoalveolar lavage
CT scan shows ground-glass infiltrates
How does Mycobacterium tuberculosis present in those with HIV
- CD4 < 500
- Fever, cough, dyspnea, weight loss, night sweats
- X ray shows apical cavitary lesion in upper lung lobes
How does TB from Mycobacterium tuberculosis often present in advanced HIV individuals with CD4 < 200
Disemminated disease affecting lungs in milary pattern. Can also affect GI tract, bone, brain and lymph nodes
What is the most common HIV associated pulmonary infection
Community aquired pneumonia
At what CD4+ count is community acquired pneumonia seen
At any CD4+ count
How does community acquired pneumonia present in those with HIV
Fever, cough, SOB, infiltrate on chest x-ray (white cloud)
What is the pathophysiology of CNS toxoplasmosis
Reactivation of latent tissue cysts in patients with prior toxoplasma infection
At what CD4+ count does CNS Toxoplamosis occur
CD4 < 100
What is the usual presentation of CNS Toxoplasmosis & how is it diagnosed?
Presentation: Fever, headache and focal neuro deficits ( seizure, aphasia, hemipareisis)
Diagnosed: MRI finding of multiple ring-enhancing lesions. Brain biopsy needed to definitely diagnose
Primary CNS Lymphoma
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
What is the leading cause of meningitis in patients with AIDS
Cryptococcal meningitis
What is the CD4+ count in those with Cryptococcal meningitis
CD4 < 100
