Pyrogens are biochemicals or microorganisms that are capable of causing fever in a patient. Many types of pyrogens exist and multiple detection systems are available..
A septic pyrogen is capable of causing infection, typically is a culturable bacterium, and is capable of being grown in culture.
An aseptic pyrogen produces fever yet cultures are negative.
Types of pyrogens:
(1) lipopolysaccharides from Gram-negative bacilli (endotoxins)
(2) exotoxins from Gram-positive bacteria
(3) other biochemical products (cell walls, etc)
(4) bacteria
(5) fungi
(6) viruses
(7) mycoplasma
Pyrogen Test
Detects
May Fail to Detect
rabbit pyrogen test
pyrogens capable of causing fever in rabbits
very low concentration
limulus amoebocyte lysate test
lipopolysaccharides from Gram-negative bacteria
any pyrogen that is not a lipopolysaccharide
culture (bacteria, fungus, virus)
intact micro-organisms
nutritional or thermal requirements outside of culture settings
