An Epidemiology Survey On The Prevalence And Associated Risk Factors Of Hearing Loss In China

WHO estimated that in2005, about278million deaf people with disabilities in theworld, accounting for4.6%of the world’s population. It has become a worldwidepublic health problem, which bring heavy burden to family and society. As theworld’s most populous country, the problem of dumb caused by hearing loss isparticularly acute in China. Early diagnosis, early intervention and early interventionof deafness had been the focus of the hearing loss. As a basis for the correspondingstrategies and measures to formulate, the correlation data is particularly important,which accurately reflect the hearing loss epidemiology characteristics andenvironmental and genetic risk factors and.This study is an epidemiology survey on the prevalence and associated risk factors ofhearing loss in China, based on the newborn hearing concurrent gene screening. Weselected newborns as the general population and NICU newborns as high-risk groupsto conducte a large-scale deaf disease epidemiological studies of genetic andenvironmental risk factors. And we researched the epidemiological charactors and andhigh risk factors in patients with auditory neuropathy spectrum disorder (ANSD).ANSD is a kind of hearing loss with special phenotypic neuropathy. At the same timewe established the Chinese heating loss gene bank, based on Professor Wang Qiujuproject team, who has set up deaf disease genetic resources collection network anddynamic monitoring system. It laid the foundation for further genetic research andrisk related research among genetic and the environment factors.The thesis is divided into four parts:PART1: Hearing loss high risk factors and epidemiological characteristics ofnewborn hearing concurrent gene screening There were118106babies who had undergoing the newborn hearing concurrent genescreening from December2006to March2014. Then we analyzed the epidemiologycharacteristics of newborn hearing concurrent gene screening, both on the overall andregional level. At the same time we analyzed the correlation and differences betweenthe screening results and the genetic and environmental factors.We gained the prevalence data of newborn hearing concurrent gene screening in13provinces and municipalities. There were100740cases passed the screening, among118106newborns. The passing rate was about85.30%. While about17366cases werereferring in the screening, the referal rate was about14.70%. Among them,867casesdidn’t pass in both the hearing and gene screening,2215cases pass the hearingscreening but did not pass the gene screening, and14284babies did not pass hearingscreening but pass the gene screening. The referal rate of hearing screening inprovinces south of the Changjiang River is significantly higher than those in the North.The referal rate was from0%to25.72%in13provinces and municipalities in thefirst-step of the hearing screening,12.83%on average. The referral rate was from1.32%to19.20%after the second-step screening by OAE between seven provinces,2.40%on average. Comparison between13provinces and cities, deaf children withincidence of risk factors, NICU hospitalization rate, newborn hearing screening andearly after screen failed, GJB2gene mutation rate, SLC26A4gene mutation rate hadobvious regional difference (P <0.01). Have found by chi-square test and correlationanalysis, the proportion difference of newborns with high risk factors, abnormal genecarriers, GJB2and SLC26A4mutation is one of the main reason for the differentscreening results between provinces.This study found that DPOAE joint AABR, hearing concurrent gene screening weresuperior to simple hearing screening, which can obviously increase the detection rate（P<0.01）. According to the result of screening,118106newborns were dividedinto four groups with different follow-up and intervention strategies.(1)100740caseswere followed-up from0to6years old with hearing screening, accounts for about 85.30%of all newborns.(2)867cases were diagnosed by the audiology joint clinic,and genetics process, accounting for about0.73%of all newborns.(3)2215cases needa lifetime high alert, accounting for about1.88%of all newborns.(4)14284cases needaudiological diagnosis, accounting for about12.09%of all newborns, who were thefocus crowd for new hearing loss gene research.This study found that the referral rate in the babies with hearing loss risk factors weresignificantly higher than those without high risk factors. The referral rate of hearingscreening was33.68%:10.29%in two groups separately. And it was4.25%:2.41%ofgenetic screening separately. We analyzed13kinds of deafness high-risk factors byLogistic regression analysis. At last we found8kinds of risk factors closely related todeafness. According to the increased risk multiples, it was clinically exist or suspectedsyndrome or genetic disorders associated with hearing impairment (2.978times), highblood bilirubin meeting the requirements of change blood (1.879times), intrauterineinfection caused by cytomegalovirus, measles virus, herpes, syphilis or toxoplasmosis(1757times), length of neonatal intensive care unit (NICU) stay for more than fivedays (1.122times), respiratory distress syndrome in preterm neonates (0.928times),family history of childhood permanent hearing impairment (0.770times), neonatalasphyxia with Apgar score0to4in1minutes or0to6points in5minutes (0.659times), craniofacial malformations (0.659times), genetic abnormalities (0.279times).At the same time we found that4kinds of factors may be risk factors, such as birthweight below1500g, viral or bacterial meningitis, extracorporeal membraneoxygenation therapy, as well as mechanical ventilation more than48hours.PART2: China NICU newborns at high risk for deafness multicenter studyThe newborn with live-birth neonatal NICU experience were screened by hearingconcurrent gene screening. At the same time we randomly selected newborns innormal delivery for comparison creening by the same way. This study is a multicenter,prospective controlled clinical research, in order to obtain the epidemiologicalcharacteristics of the combination of genetic in the Chinese deaf high-risk groups NICU newborns, and the difference of deafness onset characteristics between thenewborns of NICU and those in normal delivery.Study found: The referral rate of newborn in NICU is significantly higher than thosein ordinary room. Four common deafness gene20hot-spot mutation genetic screeningprogram is better than the four loci improving detection rate.In the first-step of the hearing screening, the referral rate in NICU newborn wasabout14.92%by DPOAE screening, and it was8.90%in ordinary delivery. Thedifference between the rates in two groups was statistically significant (P <0.05). Inthe second-step of the hearing screening, the referral rate in NICU newborn wasabout8.06%with AABR screening, and in ordinary maternity ward neonatal referalrate was0.05%. The difference between them was statistically significant (P <0.01).It was161.2times comparing NICU newborns and those in normal delivery. NICUnewborn genetic screening mutation detection rate of about11.32%.The GJB2,SLC26A4, GJB3, MTRNR1mutation detection rate was5.83%,3.77%,0.51%,0.69%seperately. Mutations detection rate of ordinary maternity ward neonatalscreening was about4.45%. Among them, The GJB2, SLC26A4, GJB3, MTRNR1mutation detection rate was1.93%,1.98%,0.43%,0.11%seperately. The carryingrate of GJB2mutations, SLC26A4mutations were significant differences betweenNICU newborns and normal delivery newborn (P <0.01). While carrying rate ofGJB3and MTRNR1mutations had no difference between the two groups (P>0.05).PART3: An epidemiological characteristics and risk factors analysis of patientswith auditory neuropathy spectrum disorder.This is a retrospective analysis on10093patients (16993ears) with sensorineuralhearing loss,5134newborns, and1406infants and young children requiredaudiological diagnosis. We retrospectively analyzed epidemiological characteristics,and its related factors of auditory neuropathy spectrum disorder (ANSD) in thosegroups. Study found: Morbidity of ANSD was highest in patients with sensorineural deafness,followed by infants and young children, the newborn. It was2.259%,1.067%,0.156%separately in three group (P<0.01).ANSD patients were from3months to73years old, average17.7years old in patientswith sensorineural deafness crowd, Course of the disease were from1month to20years, average3.4years. Morbidity between men and women had no difference (P>0.05). Bilateral ANSD incidence was about3.043%, one side was about0.564%. Theincidences have significant difference between patients with unilateral and bilateralANSD, and between the left and right (P<0.01). ANSD incidence was about4.900%in0to6years old group, about2.222%of the7to12years old group, about3.297%in aged13to18, about5.432%in19to30years old, about0.705%in31to60yearsold. And it was about0.168%in patients more than60years of age. Morbidity ofANSD had very significant difference between different age groups (P<0.01).Incidence was about2.246%in mild hearing loss patients, about2.750%in moderatecases, and about4.738%in severe patients, and1.682%in very severely cases.Morbidity of ANSD between patients in four groups had statistically significantdifference (P<0.01). Low-frequency pure tone hearing curve type was the mostcommon type in ANSD patients (P<0.01). Tympanum figure curve is given priority towith type A among different tympanum figure (P<0.01). Elicit rate of CM was about57.895%. Age and course of respectively significantly associated with PTA, ASSRthreshold, speech recognition rate (P<0.01).In the same course level, the meanbetween PTA and ASSR had significant difference (P<0.05).Deafness risk factorsexist rate was about11.842%, with high bilirubin hematic disease, family history,premature birth.In the newborn population, ANSD incidence was about0.156%. There was nosignificant difference between different gender and different childbirth way (P>0.05).ANSD incidence was about0.087%in the babies who pass the DPOAE screening,and it was about0.765%in those did not pass screening. There were very significantdifferences between them (P<0.01). It was about10.127%in those passing AABRscreening, and about0.160%referring in AABR. The difference between them was very significant (P <0.01). Refer in DPOAE first-step screen and in AABRsecond-step screen is risk factors for neonatal ANSD (P<0.01).ANSD incidence was1.067%in the infants and young children who need toaudiological diagnosis. Morbidity of ANSD had no difference between male andfemale (P>0.05). Their hearing loss levels were all severe and very severe, whichseverely deaf accounted for about5.263%, about6.686%in very severely cases. Thedifference was statistically significant between them (P<0.05). Incidence of infantsand young children without history of NICU hospitalization was about0.394%, whilecases had a history of NICU hospitalization was about1.136%. It’s about0.933%incases without deaf risk factors, and about2.469%in those with high risk factors. It’sabout5.882%in infant who were low birth weight,2.326%in children with highblood bilirubin. History of NICU, low birth weight, high bilirubin levels, prematurehad no significant correlation with ANSD (P>0.05).PART4: The establishment of the Chinese heating loss gene bank and samplemanagementThis study based on professor Wang Qiuju project team set up deaf disease geneticresources collection network and dynamic monitoring system, established the Chinesehearing loss gene bank, implements the deaf disease information and sampleresources informatization and automation management.Total deafness andaudiological examination data of580778cases, save the audiology data in212951cases, blood samples of241405, DNA32371.Among them, the hearing disorder sizefamily and sporadic cases8028cases,331listen to mental derangement spectrumdisorders, is the field in the world hearing-impaired genetic resources one of the mostabundant research team.At the same time, a collection of118106cases with neonatalhearing and genetic screening, turn on1406cases of infantile audiological diagnosisinformation and sample resources, genetic screening for2880cases of deaf collegestudents, collect sensorineural deafness in15588cases,1120cases of sudden deafness,and more than400000cases of cochlear deafness patients clinical data, for furthergenetic research and genetic hearing loss complex do with each other and theenvironment at risk related research lay the foundation.