Postnatally acquired cytomegalovirus infection in preterm infants: an update on diagnosis, management and outcomes

Postnatally acquired cytomegalovirus infection (pCMV) in very preterm and/or very low-birth-weight infants (GA<32w/VLBW) is increasingly recognised as a cause of acute and longer-term morbidity. This review presents a narrative synthesis of evidence published between April 2019 and October 2025, with expert commentary on diagnosis and management.Across study designs, there is growing evidence linking pCMV to prolonged hospitalisation, respiratory, gastrointestinal and ophthalmic morbidity. Prospective surveillance data reveal pCMV as a frequently underdiagnosed cause of sepsis-like presentations, cardiorespiratory instability and necrotising enterocolitis, often occurring without typical signs such as thrombocytopenia or liver derangement. A lower threshold for early CMV testing in symptomatic infants may identify candidates for timely targeted treatment and support antibiotic stewardship.Emerging evidence suggests that viral dynamics in pCMV differ substantially from congenital CMV (cCMV) because viral shedding in urine and saliva can be delayed or intermittent in acute disease, blood PCR may be the most pragmatic diagnostic modality for early symptomatic presentations. Targeted CMV screening of all GA<32w/VLBW infants at birth helps distinguish pCMV from cCMV, which is essential for management.Antiviral treatment with ganciclovir or valganciclovir is considered in infants with severe or sustained end-organ disease. Therapy is informed by clinical response, blood viral load, emerging pharmacokinetic data and therapeutic drug monitoring to balance efficacy with haematological toxicity. Larger-scale collaborative research is needed to ascertain the burden of pCMV disease and support future randomised controlled trials evaluating prevention and treatment strategies.