Understanding Toxoplasmosis in the United States Through “Large Data” Analyses

Abstract

Background. 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.Methods. 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.Results. 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.Conclusions. 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.

Retrospective Serological Evidence of High Exposure of Globally Relevant Zoonotic Parasite Toxoplasma Gondii in The Latvian Population

“…In a similar study in Unites States, more females than males were identified with toxoplasmosis, respectively, 59% vs 41% of the total number of cases. The number of male to female cases was most similar at early age, became increasingly different with age, toward increased incidence in females (Lykins et al, 2016). These results correspond to those observed in the present study where no difference in seroprevalence by age and gender was observed, except at age from 25 to 44 years when females had significantly higher seroprevalence than in males.…”

“…These results correspond to those observed in the present study where no difference in seroprevalence by age and gender was observed, except at age from 25 to 44 years when females had significantly higher seroprevalence than in males. This might be explained by screening of women of reproductive age, or could potentially indicate a difference in risk of exposure to the pathogen (Lykins et al, 2016). Indeed, the present study identified almost 70% of patient as cases classified as factors influencing health status or suggesting past contact with health services, which includes also monitoring of normal pregnancy.…”

Association between Toxoplasma gondii seropositivity and memory function in nondemented older adults

“…Because our sample was on average approximately ten years older, there could have been a higher death rate in the seropositive group compared to the seronegative group resulting in a loss of those subjects with potential memory deficits associated with T. gondii seropositivity. In this regard, we note that T. gondii seropositivity has been negatively associated with health status, particularly related to immune and digestive disorders (Flegr and Escudero, 2016, Flegr, et al, 2014) and has been associated with morbidity and mortality (Lykins, et al, 2016). Also, because we excluded participants with a diagnosis of dementia, the key feature of which is often memory impairment, we may have had a sample biased towards average memory performance.…”

The Relative Impact of Patient, Physician, and Geographic Factors on Variation in Primary Rhegmatogenous Retinal Detachment Management

“…This database has been used previously for ophthalmic studies as well as for studies of geographic variation in physician practice patterns. 18,19 The MarketScan database comprises longitudinal patient claims data, with a follow-up period that extends until a patient discontinues insurance (i.e., becomes uninsured, changes commercial insurers, or transitions to Medicare). The database includes patient-level demographic information, diagnosis and procedural codes for each patient encounter with a health care provider, and billing codes.…”