Communityacquired

Community-acquired refers to infections contracted outside hospital or long-term care facilities or diagnosed in the community shortly after exposure. It distinguishes illnesses arising in otherwise healthy individuals from those acquired in healthcare settings. Common community-acquired infections include pneumonia, urinary tract infections, skin and soft tissue infections, meningitis, gastroenteritis, and influenza.

Hospital-acquired (nosocomial) infections develop after hospital admission, typically after 48 to 72 hours. Healthcare-associated infections describe patients with recent healthcare exposure, such as recent hospitalization, dialysis, or residence in a long-term care facility, which can influence likely pathogens and resistance patterns.

Pathogens vary by age and geography. Typical bacteria include Streptococcus pneumoniae, Escherichia coli, and Staphylococcus aureus, while viruses such as influenza and RSV are common causes of respiratory illness. Atypical agents and community-acquired MRSA also occur. Empiric therapy is guided by the probable pathogens and local resistance data; treatment is adjusted as results become available, with emphasis on antibiotic stewardship.

Public health relevance includes vaccination, hygiene, and timely access to care. The term informs diagnostic workups and empiric treatment in community settings.