Infection is defined as the 'invasion of tissue by pathogenic organisms'. It is clinically manifested by inflammation (redness, pain, swelling, and heat) and/or the formation of pus. 

Community-acquired infection is any infection that is either apparent at the initial examination on admission to a facility, or that begins less than 48 hours after admission, or has an incubation period exceeding the interval between admission and the onset of clinical symptoms.

Infections evident on admission to the facility must be reported and documented.

Healthcare-associated Infections (HAIs) are acquired due to a facility stay. Several factors may cause them

Micro-organisms in the facility environment

Compromised or weakened status of the host

Chain of transmission in the facility

An HAI is an infection that becomes apparent more than 48 hours after admission when the known incubation periods are less than the interval between admission and the onset of clinical symptoms. 

Residents with established HAIs may develop new HAIs when

Clinical infections with the organism causing the original infection manifest at a new and different site (this may represent self-contamination)

Culture of a known site of HAIs results in the growth of new and different organisms, and the resident's condition has failed to improve or has deteriorated

Clinical signs indicate a new, different HAI

Documentation of any HAI must be made, and control measures must be implemented to prevent the occurrence of HAIs.

For these reasons, it is important to reduce the number of pathogens residents are exposed to by using the following

Frequent and conscientious hand hygiene

Standard precautions and implementing transmission-based precautions when indicated

Aseptic technique principles include careful handling of contaminated materials