Congenital cytomegalovirus infection and the risk of hearing loss in childhood A PRISMA-compliant meta-analysis

Background: Congenital cytomegalovirus (cCMV) infection is the most common cause of childhood hearing loss (HL), although the strength of this association remains limited and inconclusive. Thus, the purpose of this study was to summarize evidence regarding the strength of the relationship between cCMV and childhood HL and to determine whether this relationship differs according to patient characteristics. Methods: The PubMed, EmBase, and Cochrane Library databases were searched for studies evaluating the relationship between cCMV and HL from inception to September 2019. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were used to calculate the investigated outcomes in a random-effects model. Sensitivity, subgroup, and publication bias analyses were also performed. Results: A total of 15 studies involving 235,026 children met the inclusion criteria and were included in the final analysis. The summary results indicated that cCMV infection was associated with an increased risk of HL (odds ratio [OR]: 8.45; 95% confidence interval [CI]: 3.95-18.10; P < .001), irrespective of whether studies reported sensorineural HL (OR: 5.42; 95% CI: 1.98-14.88; P = .001), or did not evaluate HL types among their patients (OR: 11.04; 95% CI: 3.91-31.16; P < .001). However, in studies conducted in the United States (P < 0.001) and published in or after 2000 (P = 0.026), the study populations included <60% males (P < 0.001). Moreover, studies of high quality (P < .001) demonstrated a significantly greater risk of HL with cCMV infection than that in the corresponding subgroups. Conclusions: The study results suggest that cCMV infection increases the risk of HL. Further studies are required to investigate the association of cCMV infection with the risk of specific subtypes of HL.