Lecture 20: HIV/AIDS and Opportunistic Infections (Exam 2) Flashcards
What group of people does HIV infection most commonly occur in, and what two ethnicities have higher rates of diagnosis?
- gay and bisexual men
- African Americans and Latinos
majority of HIV infections happen in the GENERAL POPULATION
What is the mean time of development of AIDS from infection?
10 years
What are 3 common physical exam findings specific for HIV infection? (HKB)
- HAIRY leukoplakia of tongue, disseminated KAPOSI sarcoma, cutaneous BACILLARY angiomatosis
physical exam findings can be entirely normal, with abnormal findings ranging from completely nonspecific to high specific for HIV infection
What three tests are used to diagnose a patient suspected of HIV infection?
- HIV 1/2 Ag/Ab combination assay
- positive? –> go to HIV 1/2 Ab differentiation assay
- negative? –> no HIV
- HIV 1/2 Ab Differentiation Immunoassay
- if negative, use HIV-1 NAAT
- Nucleic Acid Amplification Test
- Nucleic Acid Amplification Test (NAAT)
- if positive w/negative Ab = ACUTE HIV
- if Positive on combo, but negative for other two
- FALSE POSITIVE TEST
What is the most widely used marker to provide prognostic information and guide HIV therapy?
CD4 LYMPHOCYTE COUNTS
TREND is more important than a SINGLE determination, as dec. counts inc. risk of opportunistic infections
What are 4 infections that can be experienced at a CD4 count > 300? (P, TB, HZ, C)
- Pnuemococcal pneumonia
- Pulmonary TB
- Herpes Zoster
- Candidiasis (oral and vaginal)
also fatigue
What 5 things can be experienced at a CD4 count < 300? (OHL, T, F, WL, D)
- Oral Hairy Leukoplakia
- Thrush
- Fever
- Weight Loss
- Diarrhea
What are 5 things that can be experienced at a CD4 count < 200?
- Pneumocystis jirovecii pneumonia
- Disseminated Histoplasmosis
- Karposi Sarcoma
- Extrapulmonary TB
- non-Hodgkins/CNS lymphoma
What are 3 infections that can be experienced at a CD4 count < 100?
- Cryptococcus (meningitis)
- Esophageal Candidiasis
- Toxoplasmosis
What are 3 infections that can be experienced at a CDR count < 50?
- Mycobacterium-avium Complex
- Cytomegalovirus
- primary CNS lymphoma
When should CD4 counts be measured in pts on antiretroviral treatments? What test can assess the level of viral replication in a patient?
- check every 3-6 months (measures immune dysfunction)
- used HIV Viral Load Tests to assess level of viral replication
Pneumocystis jirovecii pneumonia, Karposi Sarcoma, Lymphoma, CMV, Histoplasmosis, Coccidioidomycosis, Cryptococcosis, and Mycobacterium Tuberculosis are all considered what?
AIDS DEFINING ILLNESSES
What is the most common opportunistic infection associated with AIDS?
Pneumocystis jirovecii
- causes pulmonary problems such as cough/shortness of breath, as well as hypoxemia (more severe)
How is Pnemocystis jirovecii diagnosed? What should you think of if pleural effusions are present? (3)
- use chest radiograph to see DIFFUSE or PERIHILAR infiltrates (66%)
- pleural effusions are uncommon for PJP infection –> think Bacterial Pneumo, TB, or Pleural Kaposi
What two tests give definitive diagnoses of PJP and what can be used if they come back negative?
- used Wright-Giemsa stain or Direct Fluorescence Ab (DFA) test on sputum
- if sputum exam is negative in pt. still suspected of having PJP, use Bronchoalveolar Lavage (BAL) –> establishes diagnosis in > 95% of cases
What two tests findings are positive in PJP patients and what two findings are usually indicative of NOT having PJP?
(+) tests: serum lactate (LDH) and serum beta-glucan
- SBG is MORE sensitive/specific for PJP than LDH
(-) test: normal diffuse carbon dioxide/high res CT scan showing NO lung disease OR CD4 count > 250 within 2 months of prior evaluation for respiratory symptoms
What is the most common cause of pulmonary disease in HIV-infected persons?
Community Acquired Pneumonia
- bacterial, mycobacterial, viral pneumonias
- recurrent infection is AIDS DEFINING
What is the most common space-occupying lesion in HIV, where is it seen, and what does it commonly cause in AIDS patients?
TOXOPLASMOSIS
- multiple subcortical lesions in the BASAL GANGLIA
- common cause of FOCAL ENCEPHALITIS in AIDS pts (CD4 count < 100)
What is the most sensitive test for identifying Toxoplasmosis infections?
MRI (more sensitive than contrast-enhanced CT)
- typically shows MULTIPLE ring-enhancing lesions with surrounding areas of edema
What is the SECOND most common cause of space-occupying lesions in HIV and what does it look like?
PRIMARY CNS LYMPHOMA
- typically single ring-enhancing lesion but can be multiple
How can Cryptococcal Meningitis be diagnosed? (2)
- positive latex agglutination test of serum at detects its antigen (CRAG) OR having a positive culture from CSF
70-90% of pts. with CM have a positive serum CRAG
What is Primary CNS Lymphoma, when does it usually occur, and what are common symptoms it presents with?
- Diffuse, large B cell malignancy highly associated with EBV (use CSF PCR)
- occurs when CD4 count < 50
- headaches, confusion/disorientation, altered gait and balance, falls, local deficits
What are 3 gastrointestinal problems that HIV patients can experience?
Enterocolitis, Liver Disease, and Candidal Esophagitis
- usually occur due to opportunistic infections
What is a MAJOR problem that CMV can cause in HIV patients? What are 4 other things it can cause? (C, E, E, P)
- most frequently causes RETINITIS
- then colitis, esophageal ulceration, encephalitis, and pneumonitis
What is Kaposi Sarcoma, how does it present, and what can be used to diagnose pulmonary involvement?
- vascular tumor associated with HHV-8
- extracutaneous spread to oral cavity, GI, and respiratory tracts
- skin lesions usually on lower extremities, face (NOSE), oral mucosa, and genitalia
- diagnosis of pulmonary KS can be confirmed with BRONCHOSCOPY (asymptomatic chest X-Ray)
What 3 things should cause you to treat Pneumocystis jirovecii? What pharmaceutical should you give?
- CD4 count < 200, Oropharyngeal candidiasis, prior bout of PCP
- give TMP-SMX (Trimethoprim-sulfamethoxazole)
- 1 double strength table daily PO
What kinds of vaccines should be AVOIDED if treating HIV patients prophylaxtically for infections?
LIVE VACCINES
