Congenital Toxoplasmosis 2
The primary aim of the study was to determine the birth prevalence of symptomatic congenital toxoplasmosis to inform decisions about neonatal screening for congenital toxoplasmosis. Additionally, it aimed to determine the severity of clinical manifestations and age at first diagnosis in children with symptomatic toxoplasmosis according to whether infection was likely to be congenital or acquired postnatally. It also aimed to describe the management of children with suspected symptomatic congenital toxoplasmosis in the British Isles and determine the feasibility of testing for specific IgM/IgA antibodies using stored Guthrie card blood samples in children with suspected congenital toxoplasmosis.
Lead investigator
Dr R Gilbert
About the study
The primary aim of the study was to determine the birth prevalence of symptomatic congenital toxoplasmosis in order to inform decisions about neonatal screening for congenital toxoplasmosis.
To obtain an accurate estimate of the birth prevalence of symptomatic congenital toxoplasmosis, it was important to ascertain children with congenital toxoplasmosis who first presented with retinochoroiditis in childhood. Such children needed to be distinguished from the much larger number of children who acquired toxoplasma infection postnatally and developed retinochoroiditis. Retinochoroidal lesions due to congenital and postnatally acquired toxoplasmosis were indistinguishable. To differentiate between congenital and postnatal acquired infection, the study classified children based on other findings indicative of the timing of infection.
Children with probable and definite retinochoroiditis who presented with early childhood signs (history of squint in the affected eye, hydrocephalus, or history of cerebral palsy or neurodevelopmental delay from infancy) and serological evidence consistent with maternal or congenital toxoplasma infection were considered to have congenital infection.
Children whose first symptoms of retinochoroiditis took place after four years of age and who had no other findings suggestive of maternal or congenital infection were considered to have acquired the disease postnatally. As a result, the study provided information on both the birth prevalence of congenital toxoplasmosis and the incidence of postnatal infection resulting in symptomatic eye disease.
The study aimed to:
- Determine the birth prevalence of symptomatic congenital toxoplasmosis.
- Determine the severity of clinical manifestations and age at first diagnosis in children with symptomatic toxoplasmosis according to whether infection was likely to be congenital or acquired postnatally.
- Describe the management of children with suspected symptomatic congenital toxoplasmosis in the British Isles.
- Determine the feasibility of testing for specific IgM/IgA antibodies using stored Guthrie card blood samples in children with suspected congenital toxoplasmosis.
Duration
July 2002 – July 2004
Published papers
Gilbert R, Tan HK, Cliffe S, Guy E, Stanford M. Symptomatic toxoplasma infection due to congenital and postnatally acquired infection. Arch Dis Child. 2006 Jun;91(6):495-8. doi: 10.1136/adc.2005.088385. Epub 2006 Mar 17. Erratum in: Arch Dis Child. 2006 Jul;91(7):625. PMID: 16547084; PMCID: PMC2082761.
BPSU 19th Annual report 2004 -2005
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