Opportunistic illnesses Flashcards
What type of infections usually create more complications with HIV infections?
Opportunistic illnesses (OIs)
How are OIs suppressed?
with antimicrobial prophylaxis regimens in HIV and other immunocompromised patients
What is CD4 cell levels in AIDS?
<200/uL
T/F; A patient with >500/ul CD4 cells is generally not at a risk for an AIDS-defining OI
True
What pathogen causes primary or reinfection of latent infection TB?
M. Tuberculosis
What effect does Rifamycins have on CYP450?
Inducers
What does Rifamycin do to ART drugs?
decrease the plasma levels of ART drugs
What drugs replace rifampin in HIV patients; and why?
Rifabutin and Rifepentine; due to weaker CYP450 inducers
What Pathogen disseminates MAC in AIDS?
M. Avium
What does M. Intracellulare causes?
Pulmonary disease
What is the coverage of MAC infections?
Clarithromycin or Azithromycin + anti- TB drugs
T/F; Cytomegalovirus usually is activated in as a latent infection (Subacute) in AIDs pts?
True
When does CMV disease arises?
when CD4 count drops
How is CMV manifested?
Retinitis: Lesions occur near or on the retina; It causes irreversible blindness
What Medications cover CMV?
Ganciclovir, Valganciclovir, Foscarnet, Cidofovir
What pathogen reactivation cause Progressive Multifocal Leukoencephalopathy?
Papovavirus JC (JCV)
What organ is infected by JCV?
Gi tract and it remains latent
What is the pathogenesis of PML?
Virus reactivated in HIV pts
JCV destroys what part of body?
White matter of the brain
What pathogen causes Kaposi Sarcoma?
Human herpesvirus 8 (HHV8)
What immune cell is infected by HHV8?
infects B-cells
what is pathogenesis of of Kaposi’s Sarcoma?
Promote B-cells growth and prevent apoptosis
What effect does Kaposi’s Sarcoma have on skin cells?
cells from benign tumors (Skin cancer)
What causes Pneumocystis Pneumonia?
Pneumocystis Jirovecii pneumonia (PCP)
Is Pneumocytis pneumniea active in healthy patient, Why?
No, Suppressed by immune system via CD4 cells in healthy persons
When does PCP in AIDS patients arises?
when immune system can no longer contain of latent organisms
What is pathogenesis of PCP?
P. Jirovecii is a yeast-like fungi. the fungi are able to colonize and grow causing damage to alveoli
How is PCP manifested?
reactivated latent infections in the lungs give rise to pneumonia (Fluid in the lungs)
What is the coverage of PCP?
Bactrim and trimetrexate;
Pentamidine and atovaquone
How do Bactrim and Trimetrexate work?
Bactrim and trimetrexate (used with leucovorin to reduce drug toxicity) inhibit folic acid synthesis in P. jirovecii.
How do Pentamidine and atovaquone work?
inhibit electron transport (respiration = ATP synthesis) in P. jirovecii
What is Cryptococcosis?
Cryptococcus neoformans is an opportunistic yeast
Cryptococcosis occurs primarily in what patients?
in HIV pts
How is Cryptococcosis transmitted?
by aerosol inhalation
What is the pathogenesis of Cryptococcosis
Yeast spores germinate in alveoli. In AIDS pts, the CD4+ T-cells deficiency allows the disease to disseminate into the bloodstream and CNS
What is the manifestation of of Cryptococcosis?
Occurs as meningoencephalitis in AIDS pts.
Causes pulmonary (Pneumonia) and Cryptococcal CNS disease
What is Cryptococcal CNS disease?
Usually disseminates from lungs; Most common cryptococcosis presentation and it causes CNS lesions
What is the coverage of Cryptiococcosis?
Amphotericin B,
Flucytosine,
Fluconazole
How does Amphotericin B work? (Cryptococcosis)
causes leaks in ergosterol-rich fungal membranes; ADR = Nephrotoxic
How does Flucytosine work? (Cryptococcosis)
given with amphotericin B; disrupts nucleic acid synthesis; ADR = Bone marrow suppression
How does Fluconazole work? (Cryptococrossing)
Inhibits ergosterol synthesis; CYP3A4 inhibitor
what is the most frequent OI occurring in nearly all AIDS pts that are not on anti fungal prophylaxis?
Candidiasis
What is Candida?
commensal yeast of skin, genitals, and GI tract
Describe the Pathogenesis of Candidiasis?
Candidiasis occurs when CD4 cells are depleted and candida can colonize mucocutaneous surface
How is Candidiasis manifests?
Oropharyngeal and esophageal candidiasis
What is the coverage for Candidiasis?
Azole antifungals (Fluconazole = Diflucan)
Echinocandins (caspofungin, micafungin)
What are Protozoan infections?
Toxoplasmosis, Cryptosporidosis, Cystoisosporiasis
What protozoa causes toxoplasmosis?
Toxoplasma gondii
How does toxoplasmosis gets reactivated?
when CD4 count drops
What does Toxoplasmosis looks like?
CNS mass lesions in AIDS pts
Toxoplasmosis usually arises when?
When CD4 count drop
How is Toxoplasmosis transmitted?
contact with cat feces (pregnant woman should avoid little box)
What is the coverage of Toxoplasmosis?
Pyrimethamine + Sulfadiazine; Bactrim
What causes Cryptosporidiosis?
Protozoan GI pathogen
What is the epidemiology of Cryptosporidiosis?
Chronic diarrhea in HIV patients
How is Cryptosporidiosis transmitted?
Fecal-oral, waterborne
What medications cover Cryptosporidiosis?
Nitazoxanide
What is Cystoisosporiasis epidemiology?
Cause diarrheal disease in HIV pts
How is Cystoisosporiasis transmitted?
fecal-oral, waterborne
What is the coverage of Cystoisosporiasis?
Bactrim
T/F; HIV pts can also develop malignant B cell cerebral lymphoma that often present tumors containing cancerous cells infected with Epstein-Barr virus (human herpesvirus 4)
True
