Welcome to the MAPLE Study

The study objective of the Microbiome and Procalcitonin Long-term outcomes Epidemiology Study is to target emergency department (ED) patients with clinically diagnosed lower respiratory tract infection (LRTI) and determine epidemiology of changes in microbiome and associations with outcome.

  • Aim #1: To determine the epidemiology changes in human microbiome following LRTI.
  • Aim #2: To determine whether microbiome at initial LRTI presentation and changes over time are associated with outcomes.

Inclusion Criteria:

  1. ≥ 18 years old
  2. A primary clinical diagnosis in the ED of acute LRTI (< 28 days duration)

Exclusion Criteria:

  1. Conditions where physicians are unlikely to withhold antibiotics
    1. Systemic antibiotics before ED presentation
      1. All prophylactic antibiotic regimens OR
      2. Received >1 dose within 72 hours prior to ED presentation
    2. Current vasopressor use
    3. Mechanical ventilation (via endotracheal tube)
    4. Known severe immunosuppression
    5. Accompanying non-respiratory infections
    6. Known lung abscess or empyema
  2. Conditions where PCT can be > 0.25 ug/L without infection
    1. Chronic dialysis
    2. Metastatic cancer
    3. cSurgery in the past 7 days (excluding minor surgery such as skin biopsy)
  3. Conditions rendering follow-up difficult:
    1. Incarcerated or homeless
    2. Enrolled in MAPLE in the past 30 days