Cross-sectional association of Toxoplasma gondii exposure with BMI and diet in US adults

Toxoplasmosis gondii exposure has been linked to increased impulsivity and risky behaviors, which has implications for eating behavior. Impulsivity and risk tolerance is known to be related with worse diets and a higher chance of obesity. There is little known, however, about the independent link between Toxoplasma gondii (T. gondii) exposure and diet-related outcomes. Using linear and quantile regression, we estimated the relationship between T. gondii exposure and BMI, total energy intake (kcal), and diet quality as measured by the Health Eating Index-2015 (HEI) among 9,853 adults from the 2009–2014 National Health and Nutrition Examination Survey. Previous studies have shown different behavioral responses to T. gondii infection among males and females, and socioeconomic factors are also likely to be important as both T. gondii and poor diet are more prevalent among U.S. populations in poverty. We therefore measured the associations between T. gondii and diet-related outcomes separately for men and women and for respondents in poverty. Among females <200% of the federal poverty level Toxoplasmosis gondii exposure was associated with a higher BMI by 2.0 units (95% CI [0.22, 3.83]) at median BMI and a lower HEI by 5.05 units (95% CI [-7.87, -2.24]) at the 25^th percentile of HEI. Stronger associations were found at higher levels of BMI and worse diet quality among females. No associations were found among males. Through a detailed investigation of mechanisms, we were able to rule out T. gondii exposure from cat ownership, differing amounts of meat, and drinking water source as potential confounding factors; environmental exposure to T. gondii as well as changes in human behavior due to parasitic infection remain primary mechanisms.

Toxoplasmosis gondii (T. gondii) is a parasite that infects over 10 percent of the US population. T. gondii infection can cause serious health problems for some people, but most infections remain undiagnosed and subclinical. When an individual is infected, T. gondii can chronically reside in muscle and central nervous system (including brain) tissue. Previous studies have found that individuals with prior exposure to T. gondii may engage in more risky and impulsive behaviors, and risk tolerance and impulsivity may be related with individual’s diet. Our study examines whether individuals with T. gondii exposure have higher body mass index (BMI) and worse diets. We further discuss and test for alternative explanations that prevent us from establishing a causal relationship between T. gondii and BMI/diet. Overall, our results show that T. gondii exposure is related with higher BMI and worse diets among lower-income females in the US. Our results uncover a novel correlate of BMI and diets, and suggest the importance of investigating the broader public health impacts of chronic T. gondii infection.

Socioeconomic vulnerability associated to Toxoplasma gondii exposure in southern Brazil

Human toxoplasmosis, a protozoonosis caused by Toxoplasma gondii, has been described as a worldwide foodborne disease with important public health impact. Despite infection has reportedly varied due to differences in alimentary, cultural and hygienic habits and geographic region, social vulnerability influence on toxoplasmosis distribution remains to be fully established. Accordingly, the present study has aimed to assess T. gondii seroprevalence and factors associated to social vulnerability for infection in households of Ivaiporã, southern Brazil, with 33.6% population making half minimum wage or less, ranked 1,055th in population (31,816 habitants), 1,406th in per capita income (U$ 211.80 per month) and 1,021st in HDI (0.764) out of 5,570 Brazilian cities. Serum samples and epidemiological questionnaires were obtained from citizen volunteers with official City Secretary of Health assistance in 2015 and 2016. In overall, serosurvey has revealed 526/715 (73.57%) positive samples for anti-T. gondii antibodies by Indirect Fluorescent Antibody Test. Logistic regression has shown a significant increase associated to adults (p = 0.021) and elderly (p = 0.014) people, illiterates (p = 0.025), unemployment (p <0.001) and lack of household water tank (p = 0.039). On the other hand, sex (male or female), living area (urban or rural), yard hygiene, meat ingestion, sand or land contact, owning pets (dog, cat or both) were not significant variables of positivity for anti-T. gondii antibodies in the surveyed population. Although no significant spatial cluster was found, high intensity areas of seropositive individuals were located in the Kernel map where the suburban neighborhoods are located. In conclusion, socioeconomic vulnerability determinants may be associated to Toxoplasma gondii exposure. The increased risk due to illiteracy, adult or elderly age, unemployment and lack of household water tank were confirmed by multivariate analysis and the influence of low family income for seropositivity by the spatial analysis.

The impact of socioeconomic factors on the efficiency of voluntary toxoplasmosis screening during pregnancy: a population-based study

BACKGROUND

Congenital toxoplasmosis is associated with severe complications. German state health insurance covers rubella, but not toxoplasmosis, immunity screening. We analysed the effect of socioeconomic factors on the efficiency of private toxoplasmosis screening during pregnancy.

METHODS

Toxoplasmosis and rubella screening data (n = 5402 mothers) were collected within the population-based Survey of Neonates in Pomerania (SNiP).

RESULTS

At the first-trimester screening, 34.4 % (88.1 %) of expecting mothers were immune to toxoplasmosis (rubella). Susceptibility for toxoplasmosis (rubella) was observed in 39.6 % (8.9 %) and 25.8 % (2.95 %) were not tested. Data on a 2(nd) screening were available in a subgroup of women with negative immunity showing less than 45 % participation rate. Active toxoplasmosis (no rubella) infection was observed in 0.3 % (n = 17) of pregnant women. A multiple logistic regression model (AIC = 719.67; AUC = 0.725) revealed that the likelihood of participating in a second toxoplasmosis screening increased among women with a good level of education and a steady partnership and decreased with paternal unemployment and the absence of breastfeeding. The highest probability of non-participation in toxoplasmosis screening was found among women with temporal burden and family responsibilities. A cost-benefit analysis showed that covering general screening for toxoplasmosis with health insurance saved costs.

CONCLUSION

Toxoplasmosis carried a substantial risk of infection during pregnancy. Although increased socioeconomic status was positively associated with the participation in toxoplasmosis screening, this was not the case when pregnant women had strong temporal burden and family responsibilities. This data supports the need for toxoplasmosis screening among pregnant women as a general healthcare benefit covered by insurance.

Trends, productivity losses, and associated medical conditions among toxoplasmosis deaths in the United States, 2000-2010

Few studies have quantified toxoplasmosis mortality, associated medical conditions, and productivity losses in the United States. We examined national multiple cause of death data and estimated productivity losses caused by toxoplasmosis during 2000-2010. A matched case-control analysis examined associations between comorbid medical conditions and toxoplasmosis deaths. In total, 789 toxoplasmosis deaths were identified during the 11-year study period. Blacks and Hispanics had the highest toxoplasmosis mortality compared with whites. Several medical conditions were associated with toxoplasmosis deaths, including human immunodeficiency virus (HIV), lymphoma, leukemia, and connective tissue disorders. The number of toxoplasmosis deaths with an HIV codiagnosis declined from 2000 to 2010; the numbers without such a codiagnosis remained static. Cumulative disease-related productivity losses for the 11-year period were nearly $815 million. Although toxoplasmosis mortality has declined in the last decade, the infection remains costly and is an important cause of preventable death among non-HIV subgroups.

Maternal serologic screening to prevent congenital toxoplasmosis: a decision-analytic economic model

OBJECTIVE

To determine a cost-minimizing option for congenital toxoplasmosis in the United States.

METHODOLOGY/PRINCIPAL FINDINGS

A decision-analytic and cost-minimization model was constructed to compare monthly maternal serological screening, prenatal treatment, and post-natal follow-up and treatment according to the current French (Paris) protocol, versus no systematic screening or perinatal treatment. Costs are based on published estimates of lifetime societal costs of developmental disabilities and current diagnostic and treatment costs. Probabilities are based on published results and clinical practice in the United States and France. One- and two-way sensitivity analyses are used to evaluate robustness of results. Universal monthly maternal screening for congenital toxoplasmosis with follow-up and treatment, following the French protocol, is found to be cost-saving, with savings of $620 per child screened. Results are robust to changes in test costs, value of statistical life, seroprevalence in women of childbearing age, fetal loss due to amniocentesis, and to bivariate analysis of test costs and incidence of primary T. gondii infection in pregnancy. Given the parameters in this model and a maternal screening test cost of $12, screening is cost-saving for rates of congenital infection above 1 per 10,000 live births. If universal testing generates economies of scale in diagnostic tools-lowering test costs to about $2 per test-universal screening is cost-saving at rates of congenital infection well below the lowest reported rates in the United States of 1 per 10,000 live births.

CONCLUSION/SIGNIFICANCE

Universal screening according to the French protocol is cost saving for the US population within broad parameters for costs and probabilities.

[Cost analysis of toxoplasma infection control in pregnancy]

In Italy, the management of Toxoplasma infection screening in pregnant women is often unproductive and inefficient and generates a wide variability of costs. This study evaluated performance parameters in the screening management of a population of pregnant women, estimated its costs and compared them with the costs of a full application of Ministerial Documents of 1995 and 1998. We controlled until delivery 830 pregnant women who had done the first blood test between September 1st and December 31st 1997. The costs of direct and indirect testing were analysed using the Excel database and statistical software package. Of the 573 pregnant women defined 'susceptible' at the first test, only 240 (42%) did further blood tests during the II and III trimesters, 30% did no more tests and the remaining women adopted a heterogeneous behaviour. The mean cost of each screening was found to be euro 54.47/pregnancy and euro 60.05/pregnancy with a full application of the Ministerial Document of 1995. A full application of Ministerial Document of 1998, instead, would have involved a cost of euro 94.28/pregnancy for 5 tests, euro 111.40/pregnancy for 6 tests and euro 128.51 for 7 tests. The study shows that the management of toxoplasmosis screening during pregnancy needs greater attention to the prescription of tests, so that useless testing can be reduced and the efficacy of the screening improved, two important goals the Ministerial Documents were designed to achieve.

Prevention of congenital toxoplasmosis in Slovenia by serological screening of pregnant women

A programme for the prevention of congenital toxoplasmosis in Slovenia involving the screening of pregnant women for Toxoplasma infection is presented. Of 21,270 pregnant women screened for toxoplasmosis between, 1996 and the end of 1999, 13,987 (66%) were seronegative, 7,151 (34%) seropositive and 132 had primary infection; approximately 9/1,000 women were at risk of acquiring the primary infection. One hundred live-born infants of primary infected women were available for follow-up. Nine infected but asymptomatic children were born to mothers who were screened and treated in time and two congenitally infected babies were born to mothers in whom infection was detected too late in pregnancy and who therefore received no adequate treatment. It is suggested that the results obtained in this study outweigh the cost of screening for toxoplasmosis in pregnancy. Pregnant women should always be tested at the beginning of pregnancy and, in cases of seronegativity, should be re-tested in the second and third trimesters of the pregnancy. Toxoplasma primary infected pregnant women and neonates should be treated as soon as possible. However, long-term follow-up of children born to primary infected women would be necessary for an accurate evaluation of the effectiveness of the screening because of the possibility of late onset of symptoms.

PCR for the diagnosis of toxoplasmosis after hematopoietic stem cell transplantation

Toxoplasma gondii is a ubiquitous pathogen that causes significant morbidity and mortality in immunocompromised patients. Although relatively uncommon, toxoplasmosis is increasingly recognized as a severe complication of hematopoietic stem cell transplantation. Timely and accurate diagnosis of this treatable infection is critical. PCR-based testing has become the preferred method for diagnosis, occasionally replacing tissue biopsy. This article reviews the clinical, diagnostic and therapeutic aspects of toxoplasmosis in the setting of hematopoietic stem cell transplantation and the current and future role of PCR-based testing for early detection and diagnosis.

[Evaluation of prevention strategies for congenital toxoplasmosis: a critical review of medico-economic studies]

BACKGROUND

Congenital toxoplasmosis (CT) may lead to serious neurological or sensory consequences. A serological screening of women at risk of acquiring toxoplasmosis became mandatory in France, first during the visit before wedding (1978), then during the visit for pregnancy declaration (1985) and at last with a monthly follow-up during pregnancy since 1992. The efficacy and the profitability of the program was never assessed, in spite of the modification of the epidemiological context. However medico-economical studies were conducted in countries in which no prevention program for CT was available to determine the interest of an antenatal screening similar to the French one or of other prevention strategies.

METHODS

Eight studies comparing at least two strategies were selected. Methodologies used in those studies were analyzed by two independent readers with the help of a standardized scale. A score was calculated for each study.

RESULTS

Each study analyzed suffered from methodological limitations, in particular concerning the estimation of antenatal treatment efficacy, which could lead to invalidate their conclusion. The most reliable studies in regard to methodological guidelines, that is with the higher score, concluded that antenatal screening was not contributive. However, they could not be transposed directly in the present French situation, because of the difference of the epidemiological and economical context.

CONCLUSIONS

Given the difficulty to obtain a clear conclusion, it seems necessary to perform a rigorous decision analysis to identify the more effective and acceptable program in terms of human and financial costs for preventing congenital toxoplasmosis.

Burden of encephalitis-associated hospitalizations in the United States, 1988-1997

Analysis of the National Hospital Discharge Survey data for 1988-1997 revealed a substantial disease burden associated with encephalitis in the United States: on average, there were nearly 19,000 hospitalizations (7.3 hospitalizations per 100,000 population), 230,000 hospital days, and 1400 deaths annually. For most encephalitis-associated hospitalizations (59.5%), the etiologic agent was unknown or not recorded; the most common etiologic categories among known causes were "viral" (38.2%) and "other infectious" (34.1%). The most common individual diagnoses with known agents were herpetic and toxoplasmic encephalitides (each associated with an annual average of 2100 hospitalizations). Human immunodeficiency virus infection was listed among discharge diagnoses for 15.6% of hospitalizations. Rates of encephalitis-associated hospitalization were highest for children <1 year old and persons > or =65 years old. The etiology of encephalitis was unknown for persons > or =65 years old significantly more often than it was for younger persons. The average cost of an encephalitis-associated hospitalization, as determined by the Healthcare Cost and Utilization Project for 1997, was $28,151, for an annual national cost of hospitalization of $650 million.

An investigation into the incidence of toxoplasmosis in pregnancy in New Zealand

AIM

To estimate the incidence of toxoplasmosis in pregnancy in New Zealand and consider whether there is a case for screening women in pregnancy.

METHODS

The risk of maternal and fetal infection with toxoplasmosis was derived by first determining the rate of maternal seroconversion based on seroprevalence studies. The age-specific number of seroconversions in pregnancy was then estimated from the birth rate. Using reported fetal infection rates after primary maternal infection, the expected number of congenitally infected infants in one year was estimated. These incidences were compared with the number of recognised cases of toxoplasmosis infection in pregnancy and the actual number of positive IgM results at the Wellington Hospital laboratory. Using national births data, this incidence was extrapolated to estimate the number of expected cases in New Zealand.

RESULTS

The annual seroconversion rate was 0.62% (95% confidence interval 0.39-0.86). On this basis, 164 primary maternal infections are expected annually with 66 fetuses being infected. Ten patients tested positive for IgM in Wellington, which averaged only one case per year being identified over the time examined in this study.

CONCLUSIONS

Very few of the expected cases in pregnancy are diagnosed. Reporting rates were low when toxoplasmosis was a notifiable disease. Other means of improving detection, reporting and the avoidance of infection are discussed. More information is required before screening can be recommended in New Zealand.

The cost-effectiveness of preventing AIDS-related opportunistic infections

CONTEXT

Multiple options are now available for prophylaxis of opportunistic infections related to the acquired immunodeficiency syndrome (AIDS). However, because of differences in incidence rates as well as drug efficacy, toxicity, and costs, the role of different types of prophylaxis remains uncertain.

OBJECTIVE

To determine the clinical impact, cost, and cost-effectiveness of strategies for preventing opportunistic infections in patients with advanced human immunodeficiency virus (HIV) disease.

DESIGN

We developed a Markov simulation model to compare different strategies for prophylaxis of Pneumocystis carinii pneumonia (PCP), toxoplasmosis, Mycobacterium avium complex (MAC) infection, fungal infections, and cytomegalovirus (CMV) disease in HIV-infected patients. Data for the model were derived from the Multicenter AIDS Cohort Study, randomized controlled trials, and the national AIDS Cost and Services Utilization Survey.

MAIN OUTCOME MEASURES

Projected life expectancy, quality-adjusted life expectancy, total lifetime direct medical costs, and cost-effectiveness in dollars per quality-adjusted life-year (QALY) saved.

RESULTS

For patients with CD4 cell counts of 0.200 to 0.300 x 10(9)/L (200-300/microL) who receive no prophylaxis, we projected a quality-adjusted life expectancy of 39.08 months and average total lifetime costs of $40288. Prophylaxis for PCP and toxoplasmosis with trimethoprim-sulfamethoxazole for patients with CD4 cell counts of 0.200 x 10(9)/L (200/microL) or less increased quality-adjusted life expectancy to 42.56 months, implying an incremental cost of $16000 per QALY saved. Prophylaxis for MAC for patients with CD4 cell counts of 0.050 x 10(9)/L (50/microL) or less produced smaller gains in quality-adjusted life expectancy; incremental cost-effectiveness ratios were $35000 per QALY saved for azithromycin and $74000 per QALY saved for rifabutin. Oral ganciclovir for the prevention of CMV infection was the least cost-effective prophylaxis ($314000 per QALY saved). Results were most sensitive to the risk of developing an opportunistic infection, the impact of opportunistic infection history on long-term survival, and the cost of prophylaxis.

CONCLUSIONS

The cost-effectiveness of prophylaxis against HIV-related opportunistic infections varies widely, but prophylaxis against PCP or toxoplasmosis and against MAC delivers the greatest comparative value. In an era of limited resources, these results can be used to set priorities and explore new alternatives for improving HIV patient care.

Cost-benefit analysis of screening for toxoplasmosis during pregnancy

Congenital toxoplasmosis is a risk for fetus both in 'low' and 'high risk' areas. A cost-benefit analysis based on data from a Finnish prospective study (20.3% seropositivity of pregnant mothers and incidence of 2.4/1,000 seronegative pregnancies) and on Finnish cost data was performed to compare the no-screening and screening alternatives for primary toxoplasma infections during pregnancy. A maternal-feto transmission risk of 40%, effectiveness of treatment of 50%, and discount rate of 4% were used as other baseline probabilities. The calculations were carried out by decision analysis combined with sensitivity analysis. The total annual costs of congenital toxoplasmosis without screening amount to US$ 128/pregnancy/year, and with systematic serological screening, US$ 95/pregnancy. Thus screening reduces the costs by 25%. The present value of net savings in Finland would be US$ 2.1 million every year. A one-way sensitivity analysis showed that screening together with health education is preferable to health education without screening if the incidence of maternal primary infections exceeds 1.1/1,000 and effectiveness of treatment is better than 22.1%. Screening for toxoplasma infections during pregnancy is economically worthwhile even in a country with a low incidence. A scheme of systematic screening for maternal primary toxoplasma infections combined with health education should be considered.

Economic losses resulting from food-borne parasitic zoonoses

Economic losses resulting from food-borne parasitic zoonoses are difficult to assess. Estimating the global economic impact of these diseases is handicapped by inadequate information on the prevalence and public health importance of parasitic zoonoses for most countries. However, the economic losses caused by certain zoonoses has been estimated for some regions and in these instances the costs are significant. In Mexico, for example, porcine cysticercosis is responsible for a loss of more than one-half of the national investment in swine production and for more than US$17 million annually in hospitalization and treatment costs for humans with neurocysticercosis. For all of Latin America, porcine cysticercosis accounts for an economic loss of US$164 million. In Africa, losses of one to two billion dollars per year due to bovine cysticercosis have been reported. Human toxoplasmosis in the United States is estimated to be an annual economic/public health burden of more than US$400 million. The implication from these examples and other are discussed. A set of recommendations is presented for obtaining the necessary information needed to permit assigning to food-borne parasitic zoonoses their appropriate priority within each country's complex economic and public health problems.