Table 1

Characteristics of an ideal infection marker

NICU, Neonatal intensive care unit.
Clinical characteristics
  1. A well defined optimal cut off that is comparable between different NICUs

  2. Favourable diagnostic utilities:

    • sensitivity (approaching 100%)

    • specificity (>85%)

    • positive predictive value (>85%)

    • negative predictive value (approaching 100%)

  3. Detects infection at an early stage

  4. Differentiates between different types of pathogen (viral v bacterial)

  5. Guides antibiotic use (type and duration)

  6. Monitors progress of treatment

  7. Prognostication

Laboratory characteristics
  1. Stable compound

  2. Adequate time window for specimen sampling (sustained increase or decrease in level for at least 48 h after the onset of clinical manifestations)

  3. Quantitative measurement

  4. Small volume of specimen

  5. Easy method of measurement

  6. Quick laboratory turnover time

  7. Results comparable between laboratories

  8. Low cost