[Screening for cytomegalovirus infection in very low birth weight infants]

Introduction: Cytomegalovirus (CMV) is the most common congenital and acquired vertically transmitted viral infection in humans. The aim of the study is to determine the clinical relevance of this infection in very low birth weight (VLBW) infants in our area.

Patients and method: Preterm infants (gestational age ≤ 31 weeks) with a birth weight ≤ 1500g treated between March 2006 and December 2010 were included. They underwent the screening protocol for diagnosing CMV infection. CMV serology was performed on the mothers. When it was positive, their breast milk was frozen at -20°C for 72hours from the 7th day of birth. At 5 weeks, the urine of the newborn was tested for CMV-DNA. In case of a positive result, CMV-DNA was performed in breast milk and in the dry blood sample from metabolic screening.

Results: A total of 342 preterm infants were studied, with 53 (15.5%) infected by CMV: 8 (2.3%) with congenital infection, 35 (10.2%) with acquired infection, and 10 (2.9%) in which it was impossible to determine precisely. IgM-CMV+in the mother was found in two congenital infections and two acquired infections. Newborns affected by congenital CMV infection showed a lower birth weight, more intrauterine growth restriction, thrombopenia, need for platelet transfusions, early sepsis (including clinical sepsis), and cerebral ultrasound anomalies. Late sepsis was more frequent in cases of acquired CMV infection.

Conclusions: Congenital or acquired CMV infections are frequent in VLBW infants, and our protocol enables them to be diagnosed and probably prevents some acquired CMV infections by selecting which patients should freeze the breast milk.