Risk factors for hearing impairment induced by cytomegalovirus infection

Objective To investigate the risk factors for hearing impairment induced by cytomegalovirus(CMV) infection in children. Methods One hundred and fifty-eight children diagnosed with CMV infection were enrolled as subjects. Based on the results of the brainstem auditory evoked potential(BAEP) test, patients were classified into normal hearing group(n=117; BAEP ≤35) and abnormal hearing group(n=41; BAEP 35). A retrospective analysis was performed on the general information, routine blood indices, liver function, copy number of CMV-DNA in urine and breast milk. The receiver operating characteristic(ROC) curve was used to predict the copy number of CMV-DNA resulting in abnormal BAEP. The Spearman rank correlation analysis was used to test the correlations of the copy number of CMV-DNA in urine with the degree of hearing impairment and platelet count. Results The incidence rates of platelet abnormality and abnormal liver function and the copy number of CMV-DNA in urine were significantly higher in the abnormal hearing group than in the normal hearing group(P0.01). According to the ROC curve, the copy number of CMV-DNA in urine had a sensitivity of 46.3% and a specificity of 93.2% in predicting hearing impairment when it reached 1.415×106 per m L. The results of correlation analysis showed that the degree of hearing impairment was positively correlated with the copy number of CMV-DNA(r=0.382, P0.01); the platelet count was negatively correlated with the copy number of CMV-DNA in urine(r=-0.233, P=0.003). Conclusions An increased copy number of CMV-DNA in urine might be a risk factor for hearing impairment induced by CMV infection. Children are likely to have hearing impairment when the copy number of CMV-DNA reaches 1.415×106 per m L. The monitoring of hearing should be strengthened in CMV-infected children with a decreased platelet count.