Recurrence Characteristics in European Patients with Ocular Toxoplasmosis

¹ Swiss Eye Institute and Dept. Ophthalmology, University of Bern, Switzerland
² Kantonsspital St. Gallen, Switzerland
³ Swiss Eye Institute, Bern, Switzerland

^* To whom correspondence should be addressed. E-mail: justus.garweg{at}eye-institute.ch.

Accepted 7 November 2007

	Abstract

Background:. The risk of function loss after each episode of ocular toxoplasmosis (OT) supports efforts to improve our understanding of the disease. Patients and Methods: 139 patients with OT were contacted retrospectively and requested to complete a questionnaire addressing course and activity of their disease. This information was compared with that retrieved from their medical records. Sixty-three patients completed the questionnaire and were included in the study. They were allocated according to their median age to one of two groups (group 1: <20.9 years; group 2: 20.9 years).

Results: The mean reported age at the time of first ocular manifestation was 23.9 (median: 20.9, range: 0-70.5: SD ±12.9) years. The clinical diagnosis was made 3.5 years later (p=0.0008). The follow-up time was 6.5 (median: 5.0; range: 0.5-49.9; SD: ±7.6) years. The recurrence rate was higher in patients below 20.9 years (66%; n=35) than in older ones (39%; n=28; 2-Test, p<0.05). Patients reporting only one episode were elder at first manifestation [29.6 (median: 25.6; range: 10.6-70.5; SD: ±14.3) years; n=29] than those reporting two episodes [17.9 (median 19.5; range: 5.9-33.9; SD ±7.8) years; n=15 (p<0.05)]. The proportion of patients who developed a recurrence was 54-63% after each episode without a tendency to enlarge, and the interval between successive episodes remained stable between 1.0-1.7 years for the first 3 recurrences.

Conclusion: Younger OT patients carry a higher risk of developing a recurrence than older ones. After each episode, two thirds of all OT patients will develop another one.

Keywords: Ocular toxoplasmosis, Toxoplasma gondii, reactivation, recurrence, retinochoroiditis