Term
| Which opportunistic pathogens are associated with barrier impairment? |
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Definition
1) Coagulase-negative staph (epidermitis or saprophyticus)
2) Pseudomonas (often in wounds/burns)
3) Acinetobacter (gram - branching anaerobe)
4) Candida |
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Term
| Which pathogens are associated with Splenectomy and why? |
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Definition
Complement deficiency, antibodies and loss of phagocytic function
1) Strep pneumo
2) Haemophilus |
|
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Term
| Which type of infections are common in the context of B-cell or CD4 T cell deficiencies? |
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Definition
Extracellular pathogens- often Pyogenic and Encapsulated
1) Strep pneumo
2) Staphylococcus
3) Haemophilus |
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Term
| When do you most commonly see opportunistic fungal and viral infections? |
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Definition
| T-cell deficiencies such as HIV. |
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Term
| What types of opportunistic infections do you most commonly see in phagocytic deficiencies such as Neutropenia or CGD? |
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Definition
1) Aspergillis
2) All catalase-positive staph, Strep, Enterococcus
3) |
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Term
| What types of infections are important in the context of Complement deficiency? |
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Definition
Neisseria
Meningiditis and Gonorrhea. |
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Term
| Which infections are associated with AIDS? |
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Definition
1) Oral- Candia, EBV-related, HSV
2) Skin- Kaposi's sarcoma (HHV8)
3) Ocular- CMV, VZV, Toxoplasma gondii
4) Pulm- TB, Pneumocystis, Staph, Histoplasma, ect.
5) Neuro- Toxoplasma, CMV |
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Term
| What are the primary predisposing risk factors to opportunistic infections? |
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Definition
1) Young or elderly
2) Stress or malnutrition
3) Hodkin's disease, AIDS, or other immunosupressive diseases |
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Term
| What pathogens are prone to re-activation in the context of immunosuppression? |
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Definition
1) HSV
2) M. tuberculosis
3) VZV (shingles)
4) CMV (PTLS)
5) Toxoplasma gondii |
|
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Term
| What is the pathogenesis of Toxoplasma gondii? |
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Definition
Obligate intracellular parasite from cat feces and uncooked meat
1) Reactivation of latent infection in brain occurs in AIDS leading to cysts
2) Cell-mediated immune response (can destroy Tachyzoites in macrophages) |
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Term
| What is the pathogenic lifestyle of T. gondii? |
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Definition
Remember, brain cysts and eye symptoms in AIDS patients.
1) Sporozoites from feces are ingested, go to intestines and penetrate, entering Macrophages
2) Tachyzoites replicate in macrophages and lead to HOST IMMUNE response and/or dissemination to the brain or fetus
3) Bradyzoites can lye dormant in brain until immunosuppresion leads to re-activation and replication, leading to inflammation. |
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Term
| How do you prevent/diagnose Toxiplasma gondii infections? |
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Definition
1) Pregnant women should be very careful (cats!)
2) Serological testing (Ab titer) or CT (ring-like structure in brain)
3) Congenital can be asymptomatic at first, and then presents with ocular or CNS abnormalities |
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Term
| How do you diagnose fungal infections? |
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Definition
1) ***Gomori methenamine silver stain
2) PAS for polysacharides |
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Term
| Which fungi are pathogenic vs. opportunistic? |
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Definition
Pathogenic) Histoplasma (Pulm), Blastomyces (Sys) and Coccidioides (Pulm)
Opportunistic) Candida (yeast infection and thrush), Aspergillis (deep fungal infection) and Cryptococcus (CNS and pulm) |
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Term
| What is the life cycle of Coccidioides immitus? |
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Definition
Dimorphic fungus with mycelial phase in soil (INFECTIOUS) that is endemic to Southwest and Northern Mexico (Arizona most)
1) Barrel-shaped (arthroconidia) hyphae are disrupted by wind and become airborne spores
2) In humans mycelial form convert to Spherules, which reproduce by forming internal endospores
3) Spherules rupture and release endospores, which form more spherules (not infectious HUMAN TO HUMAN) |
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Term
| What disease is Coccidioides immitus infection similar to? |
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Definition
| TB pathologically and symptomatically |
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Term
| What is the pathogenesis of Coccidioides immitus? |
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Definition
1) 60% are asymptomatic and 40% develop primary disease 1-3 weeks after
2) Small percentage of 40% develop cavities in lungs (more likely in immunocompromised)
Treat with anti-fungals like Amphoterocin B |
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Term
| What clinical manifestations are associated with C. albicans infections? |
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Definition
1) Vaginal yeast infection (75% of women in lifetime)
2) Thrush in newborns and people with AIDS/cancer
3) Esophagus and GI tract in AIDS/cancer
4) Disseminated in immunocompromised with multi-organ involvement |
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