Opportunistic infection Flashcards
Pathogen
Disease causing microorganism
Commensal
Uses food supplied in the internal or external environment of the host
Virulence
Severity of the disease
Microbial latency
Microbe is dormant
Opportunistic infection
More severe in people with weak immune systems
Example of opportunistic infections
TB, PCP, toxoplasmosis, candida
What are the two types of ID
Inherited or acquired
Body response to extracellular microorganism
Phagocytes/complement/B cells/ABs
Body response to intracellular microorganism
Cytotoxic T cells, NK cells
Pathogenic bacteria
Staph aureus, strep pneumonia, listeria, haemophiliac, neisseria
Pathogenic fungi
Cryptococcus neoformans, pneumocystis jirovecii, candida
Pathogenic viruses
Cytomegalovirus, varicella-zoster, HSV, EBV
Signs of ID
- Unusual infection patterns - frequency, duration, severity
- Unusual symptoms (wound that won’t heal, mycobacterial infection with no granulomas)
- Microorganism not normally associated with that infection
- Pt not responding to antimicrobial therapy
- Negative serology test results
CD4 and HIV
- <200 is AIDS
- CD4 cells release cytokines to activate macrophages, up-regulate NK and CD8 cells, co-ordinate B cell differentiation
