This is a cross-sectional study to evaluate the utilities of a panel of biomarkers (Procalcitonin, Interleukin-6, Serum Amyloid A and Apolipoprotein C2) versus the gold standard blood culture result diagnosing late-onset neonatal sepsis (LONS) and/or necrotizing enterocolitis (NEC). Neonates who meet the initial screening criteria for suspected LONS or NEC will be recruited into the study. A group of 50 neonates who are clinically well, admitted to the nursery or general ward for reasons other than neonatal sepsis or NEC will also be recruited into the study.

The diagnosis of neonatal sepsis is challenging especially the very low birth weight infants as the signs and symptoms of sepsis are nonspecific and can be attributed to non-infected aetiologies including exacerbation of bronchopulmonary dysplasia, apnoea of prematurity and gastroesophageal reflux. Blood culture remains the gold standard for diagnosing septicaemia (either bacteremia or fungemia). However, its effectiveness in the population of preterm infants is compromised.Given the dire consequences of not treating the sepsis early, clinicians tend to have a low threshold for treatment. This leads to overuse of antimicrobials, promotion of antimicrobial resistance, exposure of infants to avoidable side effects from the antimicrobial treatment, prolonged hospitalisation and increased healthcare costs. Hence, there is a need for a clearly defined algorithm for diagnosing LONS and NEC. This study aims to examine the diagnostic utilities of a panel of sepsis biomarkers and explore if they can be incorporated into a diagnostic algorithm which hopefully, can be translated into clinical practice in the future.

Neonates with suspected LONS/NEC

Inclusion Criteria:

• Infants with signs and symptoms suggestive of sepsis and/or NEC and requiring full sepsis screening and start of intravenous antibiotic(s), or a change of antibiotics (if already on)
• Infants with postnatal age greater than 72 hours and less than 28 days of life, of all gestation
• Parents of potential neonates who are willing to give written informed consent

Healthy subjects

Inclusion Criteria:

• Clinically well infants admitted to Sibu Hospital for reasons other than neonatal sepsis or NEC
• Infants with postnatal age greater than 72 hours and less than 28 days of life, of all gestation

Exclusion Criteria:

• Infants who have lethal or life-threatening congenital abnormalities
• Infants who have chromosomal abnormalities
• Infants who have hypoxic ischemic encephalopathy
• Infants who are on steroid treatment
• Infants who received blood transfusions
• Post-operative infants

Neonates suspected of LONS and/or NEC admitted to the Neonatal Intensive Care Unit (NICU), Special Care Nursery (SCN) or Paediatric Medical 27 (PM27) wards in Sibu Hospital, Malaysia during the period of 1 July 2018 and 31 May 2020 will be screened for their eligibility. Apart from that, neonates admitted to Sibu Hospital for reasons other than neonatal sepsis or NEC will also be recruited into the study during the period of 1 June 2018 and 31 May 2020.