Understanding Toxoplasmosis in the United States Through "Large Data" Analyses

Area of Science:

• Infectious Diseases
• Epidemiology
• Public Health

Background:

• Toxoplasma gondii infection is a global health concern, affecting one-third of the world's population.
• Clinical manifestations of toxoplasmosis are diverse, with seropositivity linked to neurological diseases and malignancies.
• Objective data on the incidence and distribution of toxoplasmosis in the United States are limited.

Purpose of the Study:

• To determine the incidence and spatiotemporal distribution of toxoplasmosis in the United States.
• To analyze patterns of disease manifestation and associated comorbidities.
• To provide objective data for public health interventions.

Main Methods:

• Utilized the Truven Health MarketScan Database and International Classification of Diseases, Ninth Revision (ICD-9) codes.
• Identified patients diagnosed with toxoplasmosis and analyzed spatiotemporal distribution and disease patterns.
• Compared comorbidities in patients with toxoplasmosis against matched controls.

Main Results:

• An estimated 61,700 cases of toxoplasmosis occur annually in the US, with higher prevalence in the South.
• The mean age at diagnosis was 37.5 years, with 2.4% being congenitally infected infants.
• Significant comorbidities included HIV, autoimmune diseases, and neurological disorders; 38% had eye disease.

Conclusions:

• Toxoplasmosis contributes to morbidity and mortality in the US, with potential underestimation of retinal disease cases.
• The study suggests possible undercoding, underreporting, or undertreating of toxoplasmosis, particularly eye disease.
• Mandatory reporting and gestational screening are recommended to improve care and public health interventions.