Study Links Sleep Duration and Pregnancy to Ocular Toxoplasmosis Recurrence Risk

Ocular toxoplasmosis, which is caused by the parasite Toxoplasma gondii, is a leading cause of infectious posterior uveitis globally, with recurrence rates ranging between 40% and 79%. The study reviewed medical records from 1996 to 2023 of 86 patients treated for their first episode at a university hospital in Italy. Of these, 43 patients, all immunocompetent and without long-term antibiotic prophylaxis, completed at least 18 months of follow-up. The median follow-up period was eight years, with the last recorded recurrence occurring approximately 11 years after diagnosis.

Among the findings, nearly half of the patients (49%) experienced at least one recurrence, with a median time of six years to the first recurrence. The cumulative probabilities for recurrence were 9.4% at one year, 16.9% at two years, 27.9% at three years, and 57.9% at seven years. Overall, the incidence rate was about one recurrence per 10 person-years within the cohort.

The study determined that sleep duration was a significant risk factor for recurrence; patients sleeping six to eight hours per night had the lowest chance of experiencing further episodes. Conversely, those who reported sleeping more than eight hours had a higher recurrence rate. Researchers suggested that regular sleep might enhance stress response and inflammatory regulation, possibly lowering the risk of reactivation.

Pregnancy after diagnosis showed a notable association with recurrence risk, presenting a hazard ratio of 3.1; however, this finding did not reach statistical significance due to the small sample size of 15 women. This aligns with earlier research indicating that women of childbearing age had a recurrence risk during pregnancy that was 7.4 times higher than during non-pregnant periods.

The location of lesions also appeared to influence recurrence, with fewer recurrences noted in lesions near the fovea compared to other zones. No significant differences were observed in recurrence rates based on gender, ethnicity, age, IgM status, or the two drug regimens studied; however, a slight trend towards improved visual acuity was noted with trimethoprim compared to pyrimethamine, though this was not statistically significant.

Contrary to previous studies that reported an early spike in recurrences, this research found that the risk of recurrence remained stable over time, indicating the need for ongoing monitoring and possibly preventive strategies. The authors concluded that identifying individuals at greater risk for recurrence could facilitate secondary prophylaxis measures.