Congenital toxoplasmosis in southeastern Brazil: results of early ophthalmologic examination of a large cohort of neonates.
OBJECTIVE
To report results of early ophthalmologic examinations in a large cohort of newborns with congenital toxoplasmosis (CT) after neonatal screening.


METHODS
Cross-sectional analysis of a cohort.


METHODS
A total of 178 newborns with confirmed CT from 146,307 screened babies (95% of live births) from Minas Gerais state, southeastern Brazil.


METHODS
From November 2006 to May 2007, newborns underwent neonatal screening by immunoglobulin (Ig)M capture of dried blood samples. On all positive or suspected cases, confirmative serology was performed on babies and their mothers. Congenital toxoplasmosis was confirmed in newborns who had IgM and/or IgA and IgG, or IgG associated with suggestive ocular lesions (with IgM and IgG in the mother). Ophthalmologic evaluation consisted of indirect ophthalmoscopy with a lid speculum. Pediatric examination and radiologic studies of the central nervous system were also performed. In selected cases, biomicroscopy of the anterior segment, fundus photographs, or ultrasonography (B-scan) was performed.


METHODS
Prevalence of retinochoroidal lesions, either cicatricial or active, and their location and associated findings, such as vascular sheathing, hemorrhage, vitreous opacities, and retinal detachment, were evaluated. The occurrence of cataract, microphthalmia, microcephaly, intracranial calcification, and hydrocephalus was also recorded.


RESULTS
Of 146,307 neonates screened, 190 had CT, yielding a prevalence of 1 in 770 live births, of whom 178 (93.7%) underwent standardized ophthalmologic examination at an average age of 55.6+/-16.6 days. Of these 178 infants, 142 (79.8%) had retinochoroidal lesions consistent with CT in at least 1 eye. Bilateral involvement was noted in 113 patients (63.5%). Macular involvement was seen in 165 eyes (46.3%) of 111 patients (62.4%). Active lesions were observed in 142 eyes (39.9%) of 85 patients (47.8%). These lesions were located in the macula of 75 eyes (21.1%) and were associated with retinal vascular sheathing in 44 eyes (12.4%).


CONCLUSIONS
A high prevalence of CT was encountered (1/770) with high rates of early retinochoroidal involvement ( approximately 80%) and many active lesions (in approximately 50%), indicating a possibly more severe ocular involvement by CT in Brazil than in other parts of the world. The hypotheses of higher parasite virulence and increased individual susceptibility are being currently investigated.
Vasconcelos-Santos
Daniel Vitor
DV
Uveitis Unit, Hospital São Geraldo/HC-Universidade Federal de Minas Gerais, Belo Horizonte, Brazil. dvitor@ufmg.br
Machado Azevedo
Danuza O
DO
Campos
Wesley R
WR
Oréfice
Fernando
F
Queiroz-Andrade
Gláucia M
GM
Carellos
Ericka V Machado
EV
Castro Romanelli
Roberta M
RM
Januário
José Nelio
JN
Resende
Luciana Macedo
LM
Martins-Filho
Olindo Assis
OA
de Aguiar Vasconcelos Carneiro
Ana Carolina
AC
Almeida Vitor
Ricardo W
RW
Caiaffa
Waleska Teixeira
WT
D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D001938:Brazil / Q000453:epidemiology; D015862:Choroid Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000276:immunology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D015997:Neonatal Screening; D009887:Ophthalmoscopy; D015995:Prevalence; D012164:Retinal Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000276:immunology; D014122:Toxoplasma / Q000276:immunology; D014125:Toxoplasmosis, Congenital / Q000175:diagnosis / Q000453:epidemiology* / Q000276:immunology; D014126:Toxoplasmosis, Ocular / Q000175:diagnosis / Q000453:epidemiology* / Q000276:immunology
D000913:Antibodies, Protozoan; D007074:Immunoglobulin G; D007075:Immunoglobulin M