Sepsis is the commonest cause of neonatal mortality and is probably responsible for 30-50% of the total neonatal deaths each year in developing countries. Diagnosis of neonatal sepsis remains a major challenge, as early signs of sepsis are often non-specific and the laboratory criteria are also not fully reliable. This leads to unnecessary exposure to antibiotics before the presence of sepsis has been proven with potentially poor outcomes. Several attempts have been made to use physiologic parameters, hematologic indices, and cytokine profiles, at the time of onset of the suspected sepsis episode to identify accurately neonates with sepsis. Elevated serum level of neopterin has been shown to be an early specific and sensitive marker responsible for activation of the cellular immune system and has also been proposed to aid in the diagnosis of bacterial infection

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