Infectious Diseases - Pre-reading Flashcards
What are transmissible spongiform encephalopathies (TSEs)?
a group of progressive, invariably fatal, conditions that are associated with prions and affect the brain (encephalopathies) and nervous system of many animals, including humans, cattle, and sheep.
What are prions?
An infectious agent made of misfolded proteins with the ability to transmit their misfolded shape onto normal variants of the same protein. They characterize several fatal and transmissible neurodegenerative diseases in humans and many other animals e.g. TSEs
What is “positive” in the bacterial gram testing?
Pepticoglycan wall - a massive, thick wall will stain positive.
What are the 3 types of fungi?
- Yeasts - single cells but many form biofilms, reproduce by budding, some can can form elongated filament like buds
- Moulds - grow as filaments (hyphae), produce spores
- Dimorphic fungi
What is the infectious cause of otitis externa?
Why is it difficult to treat?
Psuedomonas aeruginosa
Forms a protective biofilm, resistant to many abx
What is this organism?
Gram positive and in pairs = strep. pnuemoniae
Which is the most haemolytic and most virulent strep?
Give examples of each
Beta-haemolytic - strep pyogenes
Alpha-haemolytic - strep pneumoniae
What are the common colonisers of the upper airways, skin and urinary tract?
- Pharyngitis
- Pneumonia
- Skin and soft tissue infections
- Urinary tract infections
- Pharyngitis: Group A strep
- Pneumonia: S. pneumoniae
- Skin and soft tissue infections: Beta-haemolytic streptococci (especially Group A Strep)
- Urinary tract infections: Group B strep, enterococci
what gram positive cocci causes UTI in young women?
Staphylococcus saprophyticus
Name 3 invasive fungal infections from environmental fungi (collonise airway etc only transiently)
- Invasive aspergillosis
- Pneumocystis jiroveci pneumonia
- Cryptococcal meningitis
How many blood cultures do you need to take?
2 sets (of 2 bottles) from 2 different sites
Total blood volume 10-20ml
What is a test that if negative rules out candidaemia?
Beta-D-glucan test
What test is used to diagnose some resp viruses?
NAAT
What is the HIV window period?
how long is it nowadays?
The window period is time between potential exposure to HIV infection and the point when the test will give an accurate result.
2-3 weeks
What is initiation of treatment prior to determination of a firm diagnosis • typically broad-spectrum (wide wild guess) abx?
Empiric therapy