Clinical Study Of Breast Milk-acquired Cytomegalovirus Infection In Extremely Preterm Infants

Objective:To assess transmission of Cytomegalovirus(CMV)to extremely preterm infants via contaminated breast milk and the prognosis of the infected infants.Methods:A total of 61 extremely preterm infants admitted by the neonatal intensive care unit(NICU)of the affiliated hospital of medical college of Qingdao University from January 2019 to December 2019 were selected for this study.These infants were born before 32 weeks of pregnancy,and were fed with breast milk that was positive for CMV DNA.Their fresh urine samples were collected at 3 days,2 weeks,3 weeks,4 weeks and then every other week to test for CMV DNA.1.According to the urine CMV test results,extremely preterm infants were divided into an infected group(N=15)and a non-infected group(N=46).General information such as gestational age,birth weight,gender,and small for gestational age(SGA)of the two groups,as well as their ways to get breast milk,clinical manifestations,and incidence of complications were collected and compared between the two groups.2.The infected group was further divided into a symptomatic group and an asymptomatic group,and clinical manifestation,rates of complications,auto-Auditory Brainstem Response(aABR)results,way to get breast milk,and use of antiviral treatment of the symptomatic subgroup were recorded.3.The infected infants were also divided according to the ways they receive breast milk into 2 groups: a mixed-feeding group(receiving both frozen and untreated fresh breast milk)and a mono-feeding group(receiving only frozen breast milk),and general conditions,clinical manifestation were compared between the two groups.Result : 1.Among the 61 extremely premature infants,15(24.6%)had breast milk-acquired CMV infection.No significant differences in gestational age,birth weight,gender,presence of twins,SGA,way of delivery,or use of blood transfusion were detected between the infected and uninfected infants(P>0.05).Mothers of the infected infants had higher virus load compared to those of the uninfected(P<0.05),but the 2groups showed no significant differences in their way to feed breast milk,breast milk consumption,or length of time on breast milk(P>0.05).No significant difference in incidence of neonatal sepsis,necrotizing enterocolitis(NEC),bronchopulmonary dysplasia(BPD),retinopathy of prematurity(ROP),or Periventricular Leukomalacia(PVL)were observed between the two groups(P>0.05).2.The symptomatic infants had an average gestational age of 27.3 ± 1.1 weeks and an average birth weight of 846 ± 141 g,both were significant lower than the asymptomatic ones,while no significant difference in amount of breast milk consumption,virus load in breast milk,or length of time on breast milk(P>0.05).Five of the infected infants weresymptomatic,manifested as thrombocytopenia,neutropenia,and liver injury in 4 of them and only thrombocytopenia and neutropenia in 1 of them.One of the symptomatic infants received antiviral therapy for persistent thrombocytopenia.3.Six of the infected infants were fed with both frozen and fresh breast milk(the mixed-feeding group),the other 9 of the infected infants were fed on only frozen breast milk(the mono-feeding group),rate of CMV infection was slightly lower in the mixed-feeding group,which was correlated lower virus load in the breast milk,but the differences were not statistically significant(P>0.05).Indicators for CMV infection,such as NEC,BPD,ROP and PVL also showed no significant differences between the two groups(P>0.05).Conclusion:1.Among the extremely preterm infants fed on CMV-contaminated breast milk,24.6% were infected,and a third of the infected showed symptoms,manifested mostly as changes in blood system and damage to the liver.No cases of serious infection were observed.2.Extremely preterm and low birth weight infants showed higher rates of symptomatic CMV infection,and high virus load in breast milk is a high-risk factor for acquired CMV infection in extremely preterm infants.3.Acquired CMV infection in extremely preterm infants increases the risk of sepsis,NEC,BPD,ROP,and PVL.Feeding frozen breast milk instead of fresh milk doesn't reduce the risk of acquired CMV infection in extremely premature infants.