title: Toxoplasma gondii in the peripheral blood of patients with acute and chronic toxoplasmosis.
abstract: OBJECTIVE
  Toxoplasmic retinochoroiditis may recur months or years after the primary infection. Rupture of dormant cysts in the retina is the accepted hypothesis to explain recurrence. Here, the authors present evidence supporting the presence of Toxoplasma gondii in the peripheral blood of immunocompetent patients.
  
  
  METHODS
  Direct observation by light microscopy and by immunofluorescence assay was performed, and results were confirmed by PCR amplification of parasite DNA.
  
  
  RESULTS
  The authors studied 20 patients from Erechim, Brazil, including acute infected patients, patients with recurrent active toxoplasmic retinochoroiditis, patients with old toxoplasmic retinal scars, and patients with circulating IgG antibodies against T gondii and absence of ocular lesions. Blood samples were analysed, and T gondii was found in the blood of acutely and chronically infected patients regardless of toxoplasmic retinochoroiditis.
  
  
  CONCLUSIONS
  The results indicate that the parasite may circulate in the blood of immunocompetent individuals and that parasitaemia could be associated with the reactivation of the ocular disease.
authors.affiliation: Hospital Israelita Albert Einstein, Av Albert Einstein 627/701, Chinuch Level, Josef Feher Building, São Paulo, SP - Brazil, CEP 05652-000.
authors.forename: Cláudio
authors.initials: C
authors.lastname: Silveira
authors.forename: Adriana Lima
authors.initials: AL
authors.lastname: Vallochi
authors.forename: Ulisses
authors.initials: U
authors.lastname: Rodrigues da Silva
authors.forename: Cristina
authors.initials: C
authors.lastname: Muccioli
authors.forename: Gary N
authors.initials: GN
authors.lastname: Holland
authors.forename: Robert B
authors.initials: RB
authors.lastname: Nussenblatt
authors.forename: Rubens
authors.initials: R
authors.lastname: Belfort
authors.forename: Luiz Vicente
authors.initials: LV
authors.lastname: Rizzo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D001938:Brazil; D002648:Child; D002825:Chorioretinitis / Q000276:immunology / Q000469:parasitology*; D016054:DNA, Protozoan / Q000097:blood; D005260:Female; D006801:Humans; D007121:Immunocompetence; D008297:Male; D051379:Mice; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D014122:Toxoplasma / Q000276:immunology / Q000302:isolation & purification*; D014126:Toxoplasmosis, Ocular / Q000276:immunology / Q000469:parasitology*; D055815:Young Adult
chemical_list: D000913:Antibodies, Protozoan; D016054:DNA, Protozoan