Related Experiment Video
Updated: Jul 6, 2026
Neonatal Murine Cochlear Explant Technique as an In Vitro Screening Tool in Hearing Research
Published on: June 8, 2017
Hearing loss in congenital toxoplasmosis detected by newborn screening
Gláucia Manzan Queiroz de Andrade1, Luciana Macedo de Resende, Eugênio Marcos Andrade Goulart
1Depto. Pediatria, FM, UFMG, Belo Horizonte, MG, Brazil.
Insights
Congenital toxoplasmosis, a common infection in Brazil, significantly impacts newborn hearing, with over 20% experiencing sensorineural deficits. Early detection and treatment are crucial for improving outcomes in affected infants.
Area of Science:
- Otolaryngology
- Infectious Diseases
- Pediatrics
Background:
- Congenital toxoplasmosis affects up to 20% of patients with sensorineural deficits.
- Early treatment improves prognosis for congenital toxoplasmosis.
- The impact of congenital toxoplasmosis on hearing impairment in Brazil is not well understood.
Purpose of the Study:
- To evaluate the hearing of newborns diagnosed with congenital toxoplasmosis through newborn screening.
- To assess the prevalence of hearing impairment in infants with congenital toxoplasmosis in Brazil.
Main Methods:
- Prospective study of newborns screened for congenital toxoplasmosis (IgM anti-T. gondii) in Belo Horizonte (2003-2004).
- Case definition included IgM/IgA within 6 months or IgG at 12 months.
- Hearing tests (behavioral audiometry, otoacoustic emissions, brainstem evoked responses) conducted at diagnosis and 12 months.
Main Results:
- 20 cases of congenital toxoplasmosis identified among 30,808 screened infants (0.065%).
- 19 infants underwent hearing evaluations; 4 (21.1%) presented sensorineural impairment.
- Three infants with impairment had no risk factors other than toxoplasmosis; two treated infants still had hearing loss.
Conclusions:
- Congenital toxoplasmosis is identified as a significant risk factor for hearing impairment in Brazilian newborns.
- The study highlights the need for further research into the impact of congenital toxoplasmosis on hearing loss.
- Findings suggest current treatment protocols may not fully prevent hearing deficits in all cases.
Unlabelled:
Congenital toxoplasmosis may cause sensorineural deficit in up to 20% of the patients and proper treatment in the first year improves prognosis. In Brazil, this infections impact on hearing impairment is unknown.
Aim:
To evaluate hearing of newborns with congenital toxoplasmosis identified by the newborn screening service.
Method:
This prospective study analyzed children with congenital toxoplasmosis identified by newborn screening (IgM anti-T.gondii) in Belo Horizonte during 2003/2004. The presence of IgM and/or IgA in the first 6 months or IgG at 12 months-of age in serology was used as case definition. Hearing tests were carried out at the time of diagnosis and 12 months later, including behavioral audiometry, evoked otoacoustic emission and brainstem evoked responses audiometry.
Results:
Among 30.808 screened children (97% of live births), 20 had congenital toxoplasmosis, 15 (75%) were asymptomatic at birth. Nineteen children were evaluated by hearing tests. Four had sensorineural impairment (21.1%). One child had other risk factors for hearing impairment; the other three had no other risk factors but toxoplasmosis. Two properly children treated still had hearing loss, in disagreement with current literature.
Conclusion:
Results suggest that congenital toxoplasmosis, common in Brazil, is a risk factor for hearing impairment and its impact on hearing loss deserves further studies.
More Related Videos
14:05Behavioral Assessment of Hearing in 2 to 4 Year-old Children: A Two-interval, Observer-based Procedure Using Conditioned Play-based Responses
Published on: January 23, 2017
06:59Intrathecal Application of a Fluorescent Dye for the Identification of Cerebrospinal Fluid Leaks in Cochlear Malformation
Published on: February 29, 2020
Related Concept Videos
01:28Toxoplasmosis
01:07Teratogenicity
01:31Hearing