Infection is the invasion of a host organism's bodily tissues by disease-causing organisms, their multiplication, and the reaction of host tissues to these organisms and the toxins they produce. Infections are caused by microorganisms such as viruses, prions, bacteria, and viroids, and larger organisms like macroparasites and fungi.
Hosts can fight infections using their immune system. Mammalian hosts react to infections with an innate response, often involving inflammation, followed by an adaptive response. Pharmaceuticals can also help fight infections.
The branch of medicine that focuses on infections and pathogens is infectious disease medicine.
Famous quotes containing the word infection:
“What, then, was war? No mere discord of flags
But an infection of the common sky
That sagged ominously upon the earth”
—Robert Graves (18951985)
“No science is immune to the infection of politics and the corruption of power.”
—Jacob Bronowski (19081974)
“This royal throne of kings, this sceptred isle,
This earth of majesty, this seat of Mars,
This other Eden, demi-paradise,
This fortress built by nature for herself
Against infection and the hand of war,
This happy breed of men, this little world,
This precious stone set in the silver sea,
Which serves it in the office of a wall,
Or as a moat defensive to a house
Against the envy of less happier lands;
This blessèd plot, this earth, this realm, this England.”
—William Shakespeare (15641616)