Hearing loss in congenital toxoplasmosis detected by newborn screening.
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.


OBJECTIVE
To evaluate hearing of newborns with congenital toxoplasmosis identified by the newborn screening service.


METHODS
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.


CONCLUSIONS
Results suggest that congenital toxoplasmosis, common in Brazil, is a risk factor for hearing impairment and its impact on hearing loss deserves further studies.
Andrade
Gláucia Manzan Queiroz de
GM
Depto. Pediatria, FM, UFMG, Belo Horizonte, MG, Brazil.
Resende
Luciana Macedo de
LM
Goulart
Eugênio Marcos Andrade
EM
Siqueira
Arminda Lucia
AL
Vitor
Ricardo Wagner de Almeida
RW
Januario
José Nelio
JN
D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D002675:Child, Preschool; D005260:Female; D034381:Hearing Loss / Q000175:diagnosis / Q000209:etiology*; D006320:Hearing Tests / Q000379:methods; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D015997:Neonatal Screening / Q000379:methods*; D011446:Prospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D014122:Toxoplasma / Q000276:immunology; D014125:Toxoplasmosis, Congenital / Q000150:complications* / Q000175:diagnosis
D000913:Antibodies, Protozoan; D007074:Immunoglobulin G; D007075:Immunoglobulin M