Opportunistic Infections of HIV Flashcards
What kinds of cells does HIV infect?
All cells expressing the CD4 antigen
-Generally infects helper T lymphocytes
What do the immunologic deficits of HIV stem from?
Lower quantity of CD4 cells and qualitative changes in cell function
What are two remarkable features of HIV immunodeficiency?
- Low incidence of certain infections such as listeriosis and aspergillosis
- Frequent occurrence of certain neoplasms such as lymphoma or Kaposi sarcoma
What is the relationship between HIV-infected individuals and allergic reactions?
-HIV infected peeps have a higher rate of allergic reactions to unknown allergens (eg. “itchy red bump syndrome”) and an increased rates of hypersensitivity reactions to medications
When does HIV become AIDS?
- Opportunistic infections/malignancies that rarely occur in the absence of severe immunodeficiency
- Several nonspecific conditions, including dementia and wasting in the presence of a positive HIV serology
- When the CD4 cell count falls below 200/mm3 regardless of the presence or absence of symptoms
What are some major conditions that define an AIDS diagnosis?
- P.carinii pneumonia (PCP): 42%
- Esophageal candidiasis: 15%
- Wasting: 11%
- Kaposi’s sarcoma: 11%
What is the median time from onset of severe immunosuppression (CD4 count<200/mm3) to an AIDS-defining diagnosis?
12-18 months w/o antiretrovirals
What improves dramatically after the initiation of antiretroviral therapy?
Humoral immunity
What classifies advanced HIV infection?
A CD4 count under 50 cells/microL
What defines a chronic nonprogressor with HIV?
HIV-seropositive with high levels of CD4 cells
What defines an elite controller with HIV?
HIV-seropositive with no evidence of viremia
What is included i the clinical spectrum of HIV infection?
- Primary infection
- Asymptomatic infection
- Early symptomatic infection
- Late symptomatic infection
What kinds of symptoms present during primary infection of HIV?
Acute retroviral syndrome
What kinds of symptoms present during asymptomatic latency of HIV?
Clinical latency - no accompanying symptoms
What kinds of symptoms present during early symptomatic infection of HIV?
Constitutional symptoms
What kinds of symptoms present during late symptomatic infection of HIV?
Advanced immunodeficiency with opportunistic infections/cancers
What kinds of infections present in the early stage of HIV (CD4>500 cells/microL)?
- Pneumococcus
- VZV
- HSV
What kinds of infections present in the middle stage of HIV (CD4 250-500 cells/microL)?
- Mycobacterium TB
- Bartonella
- Salmonella
- Candida
- Syphilis
- Kaposi sarcoma
What kinds of infections present in the late stage of HIV (CD4<200 cells/microL)?
- PCP
- Cryptococcus
- Histoplasma
- Coccidiodes
- Toxoplasma
- Rhodococcus equi
What kinds of infections present in the very late stage of HIV (CD4<100 cells/microL)?
- MAC
- Cryptosporidiosis
- PML
- CMV
What are some opportunistic infections of the lungs that can occur with HIV?
- Community acquired pneumonia
- PCP pneumonia
- Tuberculosis
What are some opportunistic infections of the skin that can occur with HIV?
- Fungal cutaneous (anywhere)
- Kaposi sarcoma
- Herpes zoster/Herpes simplex
- KMolluscum contagiosum
- Stevens-Johnson/Toxic epidermal necrolysis
What are some opportunistic infections of the HEENT that can occur with HIV?
- Cytomegalovirus retinitis
- Oral candidiasis
- Oral hairy leukoplakia
- Sinusitis
- Uveitis
What are some opportunistic infections of the central nervous system that can occur with HIV?
- AIDS dementia complex
- Cryptococcal meningitis
- HIV myelopathy
- Progressive multifocal leukoencephalopathy
- CNS lymphoma
- Toxoplasmosis
What are some opportunistic infections of the peripheral nervous system that can occur with HIV?
- Mononeuropathies
- Polyneuropathies
- Sensory neuropathies
What are some opportunistic infections of the GI tract that can occur with HIV?
- Anal carcinoma
- Cryptosporidiosis
- Entrocolitis
- Esophageal candidiasis
What are some opportunistic infections of the GU tract that can occur with HIV?
- Cervical cancer
- Vaginal candidiasis
What are the signs and symptoms of pneumocystitis carinii pneumonia?
- -Non specific
- Fever, cough, SOB
- Varying degrees of severity
- Hypoxia may be severe (PO2 under 60%)
How do you diagnose PCP?
Chest radiograph: the foundation of diagnosis
-Definitive diagnosis: Wright-Giemsa stain or direct fluorescent antibody test on induced sputum
What is the prophylaxis for PCP and when might you give it?
Prophylaxis: BactrimSS or DS qd When to give it: - CD4 count under 200 -Undiagnosed fever, night sweats, thrush, unintentional weight loss -History of a previous PCP
What is the treatment for PCP?
-2 TMP-SMX DS tabs q 8 hours for 10-21 days
What do Kaposi sarcoma look like?
- Purplish, non-blanching lesions that can appear anywhere, especially on gums
- Can be papular or nodular
What does candidiasis look like in HIV patients?
- Often esophageal, but can be oral, vaginal, or dermal
- Usually seen with CD4 count under 100 cells/microL
What is the prophylaxis for candidiasis?
- Systemic prophylaxis not recommended
- Itraconazole, fluconazole
What is the most common space-occupying CNS lesion in HIV infected persons?
-Toxoplasmosis
What are the signs and symptoms of toxoplasmosis in a patient w HIV?
- Headache
- Focal neurologic deficits
- Altered mental status
How is diagnosis of toxoplasmosis in an HIV patient made?
Diagnosis is presumed based on characteristic lesions on MRI
What is the prophylaxis for toxoplasmosis in HIV patients?
- One DS Bactrim tab daily
- Avoid undercooked meats and avoid the cat’s litter box
What is the treatment for toxoplasmosis in HIV patients?
-Pyrimethamine + sulfadiazine + leucovorin
What is progressive multifocal leukoencephalopathy and how does it present?
PML is a viral infection in the white matter of the brain
-S/Sx: aphasia, hemiparesis, cortical blindness
What is the classic radiographic finding in HIV patients with PML?
Non-enhancing white matter lesions without “mass effect” (means a mass is not actually taking up space and pushing brain matter over)
What is the treatment for HIV patients with PML?
SOME patients stabilize or improve on antiretroviral therapy (ART)
What is mycobacterium avium complex (MAC) and who does it infect?
MAC is a cousin of TB, and infects late-stage HIV patients with CD4 counts under 50 cells/microL
How is MAC diagnosed?
Blood culture or PCR
What is the treatment for MAC?
Clarithromycin 500 mg bid OR azithromycin 600 mg qd
What is enterocolitis?
- A very common complication of HIV
- Characterized by profuse, watery, recurrent diarrhea
What are the pathogens responsible for enterocolitis in patients with HIV?
Bacterial (campylobacter, salmonella, shigella)
Viral (cytomegalovirus, adenovirus)
Protozoal (cryptosporidium, entamoeba, giardia, isospora)
What is the prophylaxis for enterocolitis in those w HIV?
Proper hygiene, avoid raw oysters
How do you diagnose enterocolitis?
Stool culture, o & p
How do you treat enterocolitis in those w HIV?
- Treat based on the organism cultured
- Hydration
- There is no effective treatment for cryptosporidium
What is the most common result of a cytomegalovirus infection in those with late stage HIV?
Progressive retinitis (blurred vision, loss of central vision, can lead to retinal detachment) -HAART has had great effects on preventing this
How is progressive retinitis due to CMV diagnosed?
Fundoscopic exam
What is the prophylaxis for progressive retinitis due to CMV?
IF the CD4 count is under 50 cells/microL
-oral ganciclovir 1000 mg TID
How is CMV treated in those w HIV?
Oral valganciclovir 900 mg BID w food x 21 days THEN 900 mg daily maintenance