Eradication of Cytomegalovirus from Human Milk by Microwave Irradiation: A Pilot Study

Background: Cytomegalovirus (CMV)-infected human milk (HM) can lead to significant CMV morbidity and mortality in preterm very-low-birth weight infants. The eradication of CMV in HM while preserving its properties poses a major clinical challenge. Objective: We aimed to compare two methods used to neutralize the virus in HM, one recognized as partially effective (freezing) and another not tested to date (microwave exposure). Materials and Methods: We sampled HM from 31 CMV-seropositive mothers whose infants were hospitalized at the Lis Maternity Hospital. Fifteen samples that were positive for CMV antigen were divided into five 5 mL aliquots: the first a control, the second was frozen at -20°C for 1 day, the third was frozen at -200°C for 3 days, and the fourth and fifth aliquots were exposed for 30 seconds to microwave radiation at a low-power setting (500 W) and high-power setting (750 W), respectively. Results: Only microwave radiation at a high-power setting led to complete neutralization of CMV in all samples. Low-power microwave irradiation had a 13% failure rate while 3-day freezing and 1-day freezing had failure rates of 7% and 20%, respectively. Conclusion: It is possible to eradicate CMV successfully in HM by using microwave radiation at a high-power setting. Further studies are needed to evaluate the effect of microwave heating on breast milk properties.