Progressive thrombocytopenia as the harbinger of occult invasive candidiasis in a moderate preterm infant.

Invasive fungal infection is among the top causes of late-onset sepsis in preterm infants. Typical signs of infection are often absent, making the recognition of subtler signs critical for diagnosis. We report the case of a moderate preterm infant born to a mother with chorioamnionitis following prolonged preterm premature rupture of membranes and a prolonged course of antenatal antibiotics. On day 6, the infant exhibited recurrent non-specific symptoms which were often attributed to prematurity while the infant remained persistently afebrile. Profound progressive thrombocytopenia in the absence of overt fever prompted evaluation for fungal sepsis. Candida tropicalis was identified by blood culture and plasma targeted next-generation sequencing. A guideline-adherent antifungal regimen led to subsequent improvement.This case underscores that in moderate preterm infants presenting with non-specific symptoms and significant thrombocytopenia, even in the absence of fever, prompt evaluation for fungal sepsis is warranted. It also suggests that incorporating the duration of maternal antenatal antibiotic exposure into risk assessment could potentially help identify moderate preterm infants who might benefit from antifungal prophylaxis.