The ascarid nematodes Toxocara canis (Werner, 1782) and Toxocara cati (Schrank, 1788) may infect humans resulting in toxocariasis. A prior study associated species of Toxocara Stiles, 1905 with cognitive deficits in children. To determine if a similar association between toxocariasis and cognition exists in adults, we analysed a large dataset from the United States' Center for Disease Control's National Health and Nutrition Examination Survey. We used linear-regression and multivariate models to examine the association between toxocariasis as assessed by the presence of anti-Toxocara IgG antibodies and three measures of cognitive function - simple reaction time (SRT), symbol-digit substitution (SDS) and serial-digit learning (SDL) in 4 279 adults aged 21 to 59 years. Toxocara seroprevalence did not vary with age or blood-lead concentration but did vary with gender, ethnicity, educational attainment and poverty-to-income ratio. Controlling for gender, age, blood-lead concentration, educational attainment, ethnic background and the poverty-to-income ratio, we found that toxocariasis predicted worse performance on the SDS but not on the SRT or the SDL. Moreover, there were significant interactions between toxocariasis and age, gender and educational attainment. In conclusion, toxocariasis appears to be associated with decreased cognitive function. Interactions between toxocariasis and gender, age and educational attainment further suggest that certain groups may be more susceptible than others to the cognitive dysfunction associated with toxocariasis in adults., Lance D. Erickson, Shawn D. Gale, Andrew Berrett, Bruce L. Brown, Dawson W. Hedges., and Obsahuje bibliografii
Changes in behaviour and cognition have been associated with latent infection from the apicomplexan protozoan Toxoplasma gondii (Nicolle et Manceaux, 1908) in both animal and human studies. Further, neuropsychiatric disorders such as schizophrenia have also been associated with latent toxoplasmosis. Previously, we found no association between T. gondii immunoglobulin G antibody (IgG) seropositivity and depression in human adults between the ages of 20 and 39 years (n = 1 846) in a sample representative of the United States collected by the Centers for Disease Control as part of a National Health and Nutrition Examination Survey (NHANES) from three datasets collected between 1999-2004. In the present study, we used NHANES data collected between 2009 and 2012 that included subjects aged 20 to 80 years (n = 5 487) and used the Patient Health Questionnaire 9 (PHQ-9) to assess depression with the overall aim of testing the stability of the results of the prior study. In the current study, the seroprevalence of T. gondii was 13%. The percentage of subjects reporting clinical levels of depression assessed with the PHQ-9 was 8%. As before, we found no association between T. gondii IgG seroprevalence and depression (OR = 1.01, 95% CI = 0.81-1.25; p = 0.944) while controlling for sex, educational attainment, race-ethnicity, age, poverty-to-income ratio and cigarette smoking. We also found no positive associations between anti-T. gondii antibody titre and depression (OR = 1.00, 95% CI = 0.96-1.06; p = 0.868). Moreover, we found no association between T. gondii seroprevalence or antibody titre and suicidal ideation (seroprevalence: OR = 1.22, 95% CI = .85-1.75; p = 0.277, titre: OR = 1.05, 95% CI = 0.98-1.14; p = 0.177)., Defining depression to also include subjects currently taking antidepressant medication even with non-elevated questionnaires did not find evidence of a positive association between latent toxoplasmosis and depression. In the present study, neither T. gondii seroprevalence nor anti-T. gondii antibody titre was positively associated with depression or suicidal ideation among subjects aged 20 to 80 years., Shawn D. Gale, Andrew N. Berrett, Bruce Brown, Lance D. Erickson, Dawson W. Hedges., and Obsahuje bibliografii
Toxoplasma gondii (Nicolle et Manceaux, 1908) is an intracellular parasite that can cause ongoing latent infection persisting for the duration of a non-definitive host's life. Affecting approximately one-third of the world's population, latent toxoplasmosis has been associated with neuropsychological outcomes and a previous report suggested an association between latent toxoplasmosis and adult height. Given the large number of people with latent toxoplasmosis and its potential associations with human height, we sought to better understand the association between latent toxoplasmosis and human morphology by evaluating seropositivity for T. gondii and multiple body measures reported in the National Health and Nutrition Examination Survey III (NHANES III) and in the more recent continuous NHANES data sets from the United States Centers for Disease Control and Prevention for which data on T. gondii are available. In these analyses, latent toxoplasmosis was not associated with any of the body measures assessed in the NHANES datasets even after taking into account interactions between latent toxoplasmosis and testosterone suggesting that in these samples, latent toxoplasmosis is not associated with adult morphology including height., Andrew N. Berrett, Shawn D. Gale, Lance D. Erickson, Bruce L. Brown, Dawson W. Hedges., and Obsahuje bibliografii
The intracellular parasite Toxoplasma gondii (Nicolle et Manceaux, 1908) infects humans resulting in acute toxoplasmosis, an infection that in immunocompetent people is typically mild but results in persistent latent toxoplasmosis. In that T. gondii appears to affect dopamine synthesis and because addicting drugs affect midbrain dopamine transmission, latent toxoplasmosis could influence substance use. Using both the third and continuous National Health and Nutrition Examination Surveys from the US Centers for Disease Control and Prevention, we used logistic regression to test for associations between T. gondii seropositivity and subject self-report of having ever used tobacco, alcohol, marijuana, cocaine, heroin, or methamphetamine. In the third NHANES dataset, which included data for tobacco, alcohol, marijuana and cocaine, T. gondii seropositivity was associated with a reduced likelihood of self-reported marijuana (OR = 0.71 [95% CI: 0.58; 0.87]; p = 0.001) and cocaine use (OR = 0.72 [95% CI: 0.56; 0.91]; p = 0.006). In the continuous National Health and Nutrition Examination Surveys dataset, which included data for all six substances, T. gondii seropositivity was associated with a reduced likelihood of self-reported tobacco (OR = 0.87 [95% CI: 0.76; 1.00]; p = 0.044), marijuana (OR = 0.60 [95% CI: 0.50; 0.72]; p < 0.001), heroin (OR = 0.60 [95% CI: 0.42; 0.85]; p = 0.005) and methamphetamine use (OR = 0.54 [95% CI: 0.38; 0.77]; p = 0.001). We observed interactions between sex and T. gondii seropositivity in the prediction of self-reported use of tobacco and alcohol. Further, T. gondii seropositivity appeared to remove the protective effect of education and economic status against self-reported cigarette smoking. These findings suggest that T. gondii seropositivity may be inversely associated with some but not all types of substance use in US adults., Andrew N. Berrett, Shawn D. Gale, Lance D. Erickson, Evan L. Thacker, Bruce L. Brown, Dawson W. Hedges., and Obsahuje bibliografii