Screening could improve ocular toxoplasmosis management

This prospective study found that nonreactive and Type II Toxoplasma serotypes predominate in German ocular toxoplasmosis patients, and that the nonreactive serotype is associated with recurrence, underscoring the value of screening for management of the disease.

This study aimed to assess whether strain type is a contributing factor for the severity and frequency of ocular toxoplasmosis recurrence. Serotyping may allow identification of patients without ocular toxoplasmosis but at increased risk of developing the disease, which recommends a change in their management, such as increasing patient awareness of signs and symptoms, conducting more frequent eye exams or even providing prophylactic treatment. Also nonreactive-serotype patients with active ocular toxoplasmosis who have a higher risk of recurrences will receive appropriate management, such as preventive treatment. We are moving toward personalized medicine in uveitis.

The authors compared Toxoplasma serotypes in consecutive serum samples from 114 uveitis patients with ocular toxoplasmosis with 56 non-ocular toxoplasmosis seropositive patients who had noninfectious autoimmune posterior uveitis. A novel nonreactive serotype was significantly more common in serum samples of ocular toxoplasmosis patients (44 percent) than in non-ocular toxoplasmosis patients (7 percent) (odds ratio, 10.0; P < 0.0001). Non-ocular toxoplasmosis patients showed predominantly Type II strains (70 percent), consistent with expected frequencies in Central Europe. Ocular toxoplasmosis patients with nonreactive serotypes experienced more frequent recurrences (P = 0.037).

The authors conclude that it is important to make healthcare providers aware of these findings because current consensus among physicians is that Toxoplasma infection among healthy adults is self-limiting and relatively benign.