Congenital Cytomegalovirus Infection and Permanent Hearing Loss in Rural North Indian Children
Congenital cytomegalovirus infection (cCMV) is a leading nongenetic cause of permanent congenital or early-onset hearing loss (PCEHL). Although cCMV rates are high despite near-universal seroimmunity, the contribution of cCMV to PCEHL in the developing world is unclear.Methods:
Neonates at a rural North Indian hospital were screened for cCMV by saliva polymerase chain reaction and hearing by distortion-product otoacoustic emission testing. Cytomegalovirus (CMV)-positive infants and those not passing newborn hearing screening (NHS) were evaluated by auditory brainstem response to confirm PCEHL. Infants with cCMV and those with PCEHL were tested for mutations within the GJB2 gene.Results:
Of the 1720 infants screened, 40 (2.3%) did not pass NHS and 20 (1.2%) were CMV positive. Auditory brainstem evoked response testing confirmed unilateral or bilateral PCEHL in 11 (0.64%) children who either did not pass NHS or CMV positive. PCEHL was 20-fold higher in neonates with cCMV (2/20, 10%) than those without (9/1700, 0.5%; P < 0.01). None of 11 infants with PCEHL had connexin 26 mutations.Conclusion:
PCEHL incidence is high in India, with cCMV contributing significantly despite near-universal seroimmunity. Our findings also demonstrate the feasibility and the utility of simultaneous newborn screening for both cCMV and hearing loss in a resource-limited setting.