title: Understanding Toxoplasmosis in the United States Through "Large Data" Analyses.
abstract: Toxoplasma gondii infection causes substantial morbidity and mortality in the United States, and infects approximately one-third of persons globally. Clinical manifestations vary. Seropositivity is associated with neurologic diseases and malignancies. There are few objective data concerning US incidence and distribution of toxoplasmosis.
  
  
  
  Truven Health MarketScan Database and International Classification of Diseases, Ninth Revision (ICD-9) codes, including treatment specific to toxoplasmosis, identified patients with this disease. Spatiotemporal distribution and patterns of disease manifestation were analyzed. Comorbidities between patients and matched controls were compared.
  
  
  
  Between 2003 and 2012, 9260 patients had ICD-9 codes for toxoplasmosis. This database of patients with ICD-9 codes includes 15% of those in the United States, excluding patients with no or public insurance. Thus, assuming that demographics do not change incidence, the calculated total is 61 700 or 6856 patients per year. Disease was more prevalent in the South. Mean age at diagnosis was 37.5 ± 15.5 years; 2.4% were children aged 0-2 years, likely congenitally infected. Forty-one percent were male, and 73% of women were of reproductive age. Of identified patients, 38% had eye disease and 12% presented with other serious manifestations, including central nervous system and visceral organ damage. Toxoplasmosis was statistically associated with substantial comorbidities, including human immunodeficiency virus, autoimmune diseases, and neurologic diseases.
  
  
  
  Toxoplasmosis causes morbidity and mortality in the United States. Our analysis of private insurance records missed certain at-risk populations and revealed fewer cases of retinal disease than previously estimated, suggesting undercoding, underreporting, undertreating, or differing demographics of those with eye disease. Mandatory reporting of infection to health departments and gestational screening could improve care and facilitate detection of epidemics and, thereby, public health interventions.
authors.affiliation: Pritzker School of Medicine.
authors.forename: Joseph
authors.initials: J
authors.lastname: Lykins
authors.affiliation: Committee on Genetics, Genomics, and Systems Biology.
authors.forename: Kanix
authors.initials: K
authors.lastname: Wang
authors.affiliation: Department of Ophthalmology and Visual Sciences.
authors.forename: Kelsey
authors.initials: K
authors.lastname: Wheeler
authors.affiliation: Department of Ophthalmology and Visual Sciences.
authors.forename: Fatima
authors.initials: F
authors.lastname: Clouser
authors.affiliation: Department of Ophthalmology and Visual Sciences.
authors.forename: Ashtyn
authors.initials: A
authors.lastname: Dixon
authors.affiliation: Department of Ophthalmology and Visual Sciences.
authors.forename: Kamal
authors.initials: K
authors.lastname: El Bissati
authors.affiliation: Department of Ophthalmology and Visual Sciences.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Center for Health and Social Sciences (CHeSS).
authors.forename: Christopher
authors.initials: C
authors.lastname: Lyttle
authors.affiliation: Department of Medicine Department of Human Genetics Computation Institute.
authors.forename: Andrey
authors.initials: A
authors.lastname: Rzhetsky
authors.affiliation: Department of Ophthalmology and Visual Sciences Department of Pediatrics (Infectious Diseases), Institute of Genomics, Genetics, and Systems Biology, Global Health Center, Toxoplasmosis Center, CHeSS, The College, University of Chicago, Illinois.
authors.forename: Rima
authors.initials: R
authors.lastname: McLeod
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001327:Autoimmune Diseases / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D005260:Female; D015658:HIV Infections / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D007223:Infant; D038801:International Classification of Diseases; D008297:Male; D008875:Middle Aged; D009017:Morbidity; D009422:Nervous System Diseases / Q000453:epidemiology*; D015995:Prevalence; D014123:Toxoplasmosis / Q000145:classification / Q000453:epidemiology*; D014481:United States / Q000453:epidemiology; D055815:Young Adult
keywords: ICD-9 code; Toxoplasma gondii; Truven Health MarketScan Database; toxoplasmosis; “large data”