INFECTION

Infections are counted from the most popular diseases
over the world .





"Infectious disease" redirects here.

 For the medical specialty
, see Infectious disease (medical specialty).
For other uses
, see Infection (disambiguation).
Infectious disease
Malaria.jpg
A false-colored electron micrograph shows a malaria
 sporozoite migrating through the midgut epithelia.
Classification and external resources
Specialty Infectious
 disease
ICD-10 A00-B99
ICD-9-CM 001-139
DiseasesDB 28832
MeSH D003141
[edit on Wikidata]
Infection is the invasion of an organism's body
 tissues by disease-causing agents, their multiplication, and the reaction of host tissues to these organisms and the toxins they produce.[1][2] Infectious disease, also known as transmissible disease or communicable disease, is illness resulting from an infection.

Infections are caused by infectious agents
 including viruses, viroids, prions, bacteria, nematodes such as parasitic roundworms and pinworms, arthropods such as ticks, mites, fleas, and lice, fungi such as ringworm, and other macroparasites such as tapeworms and other helminths.

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.[3]

Specific medications used to treat infections include antibiotics, antivirals, antifungals, antiprotozoals, and antihelminthics. Infectious diseases resulted in 9.2 million deaths in 2013 (about 17% of all deaths).[4] The branch of medicine that focuses on infections is referred to as infectious disease.[5]