Exam 5 lecture 2 (pt 1) Flashcards
what are some risk factors for infection in immunocompromised host
Neutropenia
Immune system defects
Destruction of protective barriers
environmental contamination/alternation of microbial flora
What ANC is neutropenia?
less than 1000 cells
high risk<500
Higest risk<100
What are the two types of immune system defects
Defects in cell mediated immunity
Defects in humoral immunity
Link between duration and rapidity of decline and risk for patient
Increased rapidity and duration leads to increased risk
Highest risk patients have neutropenia lasting how long
7-10 days
What are common bacterial pathogens seen in infections seen in immunocompromise dhosts
S aureus
enterobacterales
pseudomonas aeruginosa (top 3 highest fatality)
S. epidermidis
Streptococci
Enterococcus
what are fungi seen in immune compromise dpatients
Candida
Aspergilis
Zygomycetes
What are viruses seen in immune compromised patients
HSV
VZV
CMV
What are cell mediated immuntity (cells involved and intra/extracellular)
T lymphocytes
Primary defense against intracellular pathogens
What is humoral immuntity (cells involved and intra/extracellular)
B lymphocytes
Primary defense against extracellular pathogens
defects in T lymphocyte and macrophage function relay on 2 things
Underlying disease (hodgkins lymphoma)
Immunosuppressive drugs (tacrolimus and sarolimus, steroids)
Defects in B lymphocyte function and macrophage function relay on 2 things
Underlying disease (MM, CLL, splenectomy)
Immunosuppressive drugs
Common pathogens seen in skin destruction of protective barriers
- Venipuncture/lines
- Common pathogens
-S. Aureus
- S. Epidermis
- Candida spp
What are common pathogens seen in mucous membranes
chemotherapy, radiation
Common pathogens
bacteria
- s. aureus
- s epidermis
- streptococci
- enterobacterales
- P. aeruginosa
- Bacteroides spp
Fungi
- candida spp
Virus
-HSV
compare pathogens seen in mucous membranes and surgery
same except no streptococci in surgery
what happens to oropharyngeal flora in hospitalized pts
They rapidly change to gram negative bacilli in hospitalized pts
What is the number 1 cause of death in neutropenic cancer pts
Infection
profound neutropenia (ANC<500)= greatest risk of infection
febrile episodes are attributed to microbiologically documented infection how often
30-40%
(we grow something only 20-40% of the time)
what % of infections in neutropenic cancer patients are gram positive
45-75%
What are gram positive and gram negative bacterial infections seen in neutropenic cancer patients
Gram Positive
staph
- MSSA, MRSA
Viridians strep
- mucositis
Gram negative
Enterobacterales
- E coli, klebsiella spp
P. Aeruginosa
- high morbidity and mortality
What type of fungal infections do we see with neutropenic cancer patients
- Candida spp (60%)
- aspergillus spp
WHo is at highest risk for invasive fungal infections
Prolonged neutropenia + broad spectrum antibiotics and/or steroids
who is at risk for aspergillus spp
Heme and HSCT patients- prolonged neutropenia
What are other infections that attack neutropenic cancer patients
viruses
- HSV
Protozoan
- Pneumocystitis jirovecci (PJP)
- toxoplasma gondii
- TMP/SMX