28. Opportunistic Infections Flashcards
(23 cards)
Opportunistic infections are caused by pathogens that always cause disease. Is this statement True or False?
False
What is a common opportunistic pathogen associated with device-related infections?
Staph epidermidis
What is an opportunistic pathogen?
Has low intrinsic virulence but can cause serious infections in immunocompromised or foreign body
Which endogenous bacteria are common opportunistic pathogens?
Staph epidermidis
Staph aureus
E.coli
Enterococci
Which exogenous bacteria are common opportunistic pathogens?
Staph aureus and MRSA Enterobacteriaecae Pseudomonas Listeria TB
Which viruses are common opportunistic pathogens?
Herpes viruses
Polyomaviruses
Parvovirus B19
Hep B
Which fungi are common opportunistic pathogens?
Candida
Aspergillus
Cryptococcus neoformans
PCP
Which protozoa are common opportunistic pathogens?
Toxoplasma gondii
Cryptosporidium parum
Which infections are neutropaenic patients more at risk of?
BSI and RTI
What are the sources of bacterial entry in a neutropaenic patient?
Chemo-induced mucositis
Breaks in GI lining
IV lines
Define neutropaenia?
Neutrophil count less than 500 cells/mm3
What pathogens commonly cause neutropaenic sepsis?
Gram + cocci
Gram - bacilli
Aspergillus and candida
What are the immune deficiencies in a post-transplant patient?
Lymphopaenia
Impaired cytokine release
What are the common infections in renal transplant patients?
UTIs
BSIs
CMV 2-4 months after
PCP after 4 months
What are the causes of immunodeficiency in a premature neonate?
Low body weight
Low antibody levels
Impaired migration of neutrophils
Impaired response to interferon
What are the common opportunistic pathogens in a premature neonate?
E.coli Group B strep Listeria Candida Herpes simplex
Which bacteria are most likely to colonise in wounds?
Staph aureus
Pseudomonas
What investigations should be done if there is suspicion of an opportunistic infection?
Blood cultures
CT for aspergillosis
PCR for CMV
BAL for PCP
What test might be a false negative in an immunosuppressed patient?
Serology
What are the steps in treating a neutropaenic fever?
- Antibiotic with activity against pseudomonas (piperacillin and gentamicin)
- Add vancomycin to cover gram +
- Add anti-fungal
- Add anti-viral
What are possible causes of ongoing pyrexia?
Occult abscess IV catheter infection Antibiotic resistant organism Profound neutropaenia Invasive fungal disease
What is the empiric treatment for invasive pulmonary fungal disease?
Amphotericin B
What is the treatment for confirmed aspergillosis?
Voriconazole
