Is pneumonia diagnosed 2 months after hospital discharge considered hospital-acquired pneumonia (HAP) or community-acquired pneumonia (CAP)?

From the Guidelines

Pneumonia diagnosed 2 months after hospital discharge is considered community-acquired pneumonia (CAP), not hospital-acquired pneumonia (HAP). Hospital-acquired pneumonia is generally defined as pneumonia that develops 48 hours or more after hospital admission 1. The 2-month timeframe in this scenario is well beyond that window. By 2 months post-discharge, the patient's microbiome and risk factors have usually returned to their baseline community state. However, it's essential to note that some risk factors from hospitalization can persist for weeks to months after discharge, such as weakened immune function or residual lung damage, which may increase susceptibility to community-acquired pneumonia 1. When evaluating such cases, clinicians should consider:

• The patient's current living situation and exposures
• Any ongoing medical treatments or devices (e.g., feeding tubes)
• Recent antibiotic use
• The patient's overall health status and immune function Treatment should follow community-acquired pneumonia guidelines unless there are specific risk factors for resistant organisms, as outlined in the guidelines for the management of adults with hospital-acquired, ventilator-associated, and healthcare-associated pneumonia 1. This typically includes antibiotics like:

• Amoxicillin 1g three times daily for 5-7 days, or
• Doxycycline 100mg twice daily for 5-7 days, or
• A macrolide such as azithromycin 500mg once daily for 3 days Always assess the patient's individual risk factors and local resistance patterns when selecting treatment, taking into account the principles of avoiding excessive antibiotics and tailoring therapy to the results of lower respiratory tract cultures 1.

From the Research

Definition of Hospital-Acquired Pneumonia (HAP) and Community-Acquired Pneumonia (CAP)

• HAP is defined as radiologically confirmed pneumonia occurring ≥48h after hospitalization, in non-intubated patients 2
• CAP is traditionally categorized as pneumonia occurring outside of the hospital setting, but can also be associated with health care risk factors, in which case it is classified as health care-associated pneumonia (HCAP) 3

Health Care-Associated Pneumonia (HCAP)

• HCAP is a category of nosocomial pneumonia defined by the 2005 American Thoracic Society/Infectious Diseases Society of America (ATS/IDSA) guidelines to include any patient who has been hospitalized in an acute care hospital for 2 or more days within the past 90 days 4
• HCAP also includes residents of a nursing home or long-term care facility, recipients of recent intravenous antibiotic therapy, chemotherapy, or wound care within the past 30 days, or patients who have attended a hospital or hemodialysis clinic 4

Diagnosis of Pneumonia 2 Months After Hospital Discharge

• Based on the definitions above, pneumonia diagnosed 2 months after hospital discharge would not be considered HAP, as it does not occur during hospitalization or within 48 hours of hospitalization 2
• However, if the patient has been hospitalized in an acute care hospital for 2 or more days within the past 90 days, it could be considered HCAP 4
• The diagnosis of pneumonia in this scenario would depend on the specific risk factors and circumstances of the patient, and would likely be classified as either CAP or HCAP 3, 4, 5

Key Factors in Determining the Type of Pneumonia

• Time of onset of pneumonia in relation to hospitalization 2
• Presence of health care risk factors, such as recent hospitalization, residence in a nursing home, or receipt of intravenous antibiotic therapy 3, 4
• Underlying medical conditions and comorbidities 5