Evaluation of cellulose pads as a method to detect cytomegalovirus DNA in neonatal urine

Background Several approaches exist to screen neonates for congenital cytomegalovirus infection. We here describe a new method using cellulose pads for urine collection and its evaluation in an experimental and a clinical setting. Methods We systematically tested the effect of storage duration of the pads after exposure to cytomegalovirus-positive urine, meconium contamination and specimen handling on the cytomegalovirus load and the detection rate. Further, the method was tested in clinical practice in a cohort of 500 neonates. Results Following exposure of urine pads with cytomegalovirus-positive urine, the viral load decreased after 15 min, 12 h, 24 h, and 7 days to 63.2%, 42.1%, 31.6%, and 9.3% of the baseline value. Cytomegalovirus detection rate after seven days was 100%. Contamination with meconium resulted in a comparable reduction of the viral load. The detection rate for dried urine pads after seven days was 93.3%. In clinical practice, urine collection from pads was successful in 73.6% by the first attempt and in 26.4% by the second attempt. Conclusions Urine collection using cellulose pads seems feasible regardless of a reduction of the cytomegalovirus load due to exposure to the pad itself or to meconium. Drying of the exposed urine pad should be avoided.