Multiple cases of acquired toxoplasmosis retinitis presenting in an outbreak

Objective: The purpose of the study was to examine the variability in presentation and outcome of individuals presenting with acquired toxoplasmosis retinitis in the setting of an outbreak of the disease. Design: The study design was a case series. Participants: Twenty-one eyes of 20 patients with equal gender distribution and a mean age of 54 years followed for 38 to 170 weeks (mean 113.7 weeks) were studied. Intervention: Systemic antimicrobials and corticosteroids when indicated were given. Main Outcome Measures: Visual acuity, media inflammation and clarity, resolution of active retinitis, and appearance of recurrences were observed. Results: Fifteen of 21 lesions were active, and 7 of the total number of lesions fell within the macula-peripapillary region. Overall, vision improved with treatment except in cases of macular involvement (3 cases) and persistent vitritis (3 cases). Four recurrences have occurred to date. Conclusions: This is the largest reported outbreak of acquired toxoplasmosis retinitis occurring within a single outbreak. Twenty-one eyes of 20 patients presented with retinal lesions, and on average, those treated for active retinitis had improvement in vision.