What do we know about risk factors for infection in humans with Toxoplasma gondii and how can we prevent infections?

Oral Sex as a Potential Route for Toxoplasma Gondii Transmission: Experiment with Human Semen and Laboratory Mice Model

PURPOSE

Toxoplasma gondii is one of the most widespread parasites in the human population globally. Several modes of its transmission have been proposed: some are well-researched and confirmed, others remain unconfirmed. One unconfirmed hypothesis pertains to potential transmission of Toxoplasma gondii via oral sex (fellatio) in humans. A recent study found tissue cysts in the semen of men with latent toxoplasmosis. Therefore, we aimed to test the hypothesis of Toxoplasma gondii transmission through oral sex experimentally.

METHODS

Eighty-two laboratory mice were orally administered semen samples from 41 men with latent toxoplasmosis. These semen samples were examined for the presence of Toxoplasma gondii DNA using PCR.

RESULTS

We detected Toxoplasma gondii DNA in three of the 41 semen samples from men with latent toxoplasmosis. Oral administration of semen samples to laboratory mice did not result in parasite transmission.

CONCLUSION

We have not demonstrated the transmission of Toxoplasma to mice by oral exposure to semen from infected men. While this does not conclusively rule out the possibility of such transmission in humans, the results suggest that, if it does occur, this mode of transmission is likely infrequent.

Overview of Apoptosis, Autophagy, and Inflammatory Processes in Toxoplasma gondii Infected Cells

Toxoplasma gondii (T. gondii) is an obligate intracellular parasite. During the parasitic invasion, T. gondii creates a parasitophorous vacuole, which enables the modulation of cell functions, allowing its replication and host infection. It has effective strategies to escape the immune response and reach privileged immune sites and remain inactive in a controlled environment in tissue cysts. This current review presents the factors that affect host cells and the parasite, as well as changes in the immune system during host cell infection. The secretory organelles of T. gondii (dense granules, micronemes, and rhoptries) are responsible for these processes. They are involved with proteins secreted by micronemes and rhoptries (MIC, AMA, and RONs) that mediate the recognition and entry into host cells. Effector proteins (ROP and GRA) that modify the STAT signal or GTPases in immune cells determine their toxicity. Interference byhost autonomous cells during parasitic infection, gene expression, and production of microbicidal molecules such as reactive oxygen species (ROS) and nitric oxide (NO), result in the regulation of cell death. The high level of complexity in host cell mechanisms prevents cell death in its various pathways. Many of these abilities play an important role in escaping host immune responses, particularly by manipulating the expression of genes involved in apoptosis, necrosis, autophagy, and inflammation. Here we present recent works that define the mechanisms by which T. gondii interacts with these processes in infected host cells.

Presence of Toxoplasma gondii tissue cysts in human semen: Toxoplasmosis as a potential sexually transmissible infection

OBJECTIVES

Toxoplasma gondii is a widely prevalent protozoan parasite in human populations. This parasite is thought to be primarily transmitted through undercooked meat and contamination by cat feces. Here, we seek to determine if Toxoplasma gondii cysts can be found within human semen.

METHODS

We used a mixture of histological and immunofluorescence stains to visualize Toxoplasma gondii cysts in thin smears of human semen. Further, we probed for presence of bradyzoite-specific mRNA transcription using in-situ hybridization.

RESULTS

We visualized Toxoplasma gondii cysts in ejaculates of immune-competent and latently infected human volunteers. We confirmed the encystment by probing transcription of a bradyzoite-specific gene in these structures. These observations extend previous observations of the parasite in semen of several non-human host species, including rats, dogs, and sheep.

CONCLUSIONS

Toxoplasma gondii infection is a clinically significant infection, in view of its high prevalence, its purported role in neuropsychiatric disorders such as schizophrenia, as well as in the more serious form of congenital toxoplasmosis. Our demonstration of intact Toxoplasma gondii cysts in the ejaculate supports the possibility of sexual transmission of the parasite and provides an impetus for further investigations.

Assessment of intestinal and blood protozoan infections among pregnant women visiting ante-natal care at Tafo Hospital, Ghana

Introduction

Intestinal and blood protozoans cause morbidity and mortality in both pregnant women and developing foetuses worldwide. It constitutes a major health problem in many tropical areas in Africa. This study assessed the prevalence of intestinal and blood protozoans’ parasitic load and their risk factors among pregnant women visiting antenatal care at Tafo Hospital, Ghana from November 2016 to January 2017.

Method

A pilot cross-sectional study was conducted among consented pregnant women who visited antenatal care at Tafo Government Hospital, Kumasi Ghana. Structured questionnaires were administered to obtain socio-demographic data, knowledge on protozoan infections, and their risk factors among study participants. A stool sample was obtained from each participant for the microscopic examination of the intestinal protozoa. Venous blood was taken from participants for the detection of Plasmodium and Toxoplasma gondii infections. Wet mount and the faecal protozoan concentrated method were done for the identification of intestinal parasites. Blood films and serological examination for malaria rapid diagnostic tests (RDT) were done for identification of Plasmodium parasites while an Enzyme-linked immunosorbent assay (ELISA) was used for detecting the antibodies of T. gondii among participants. Data were analyzed using statistical packages for the social sciences (SPSS).

Results

The mean age of the study participants was 27.83, and ranges from 18 to 40 years. The majority of the participants (82.2%) had never experienced stillbirth nor spontaneous abortion. Intestinal parasites were found in 36.7% of participants. Giardia lamblia (28.1%), Cryptosporidium parvum (5.3%), and Entamoeba histolytica/dispar (3.3%) were among the intestinal protozoans detected. T. gondii antibodies were detected by high levels of immunoglobulins, resulting in IgG (48.0%) and IgM (11.3%) being found among participants, with 7.3% testing positive for both IgM and IgG. The prevalence of malaria infection among the study participants was 2.7%. The consumption of raw or cooked vegetables had significant influence on their intestinal and blood protozoan infections status (p = 0.004) (OR = 0.32, CI = 0.12–0.86). There was a significant association between Hb levels and malaria (p = 0.014) and that of intestinal protozoans (p = 0.035).

Conclusion

The prevalence of intestinal protozoans and blood protozoans such as T. gondii were high and therefore effective measures should be put in place to reduce the infectivity. Environmental hygiene should be improved and education by relevant agencies should be intensified on the possible transmission of intestinal and blood parasite infections given the possible role of these infections in adverse pregnancy outcomes.

Epidemiology of Toxoplasmosis among the Pakistani Population: A Systematic Review and Meta-Analysis

Toxoplasma gondii is an intracellular obligate parasite that causes toxoplasmosis, a zoonotic infection that affects warm-blooded animals and humans worldwide. To comprehensively characterize the disease condition in Pakistan for future reference, we ascertained the prevalence of Toxoplasma infection and predisposing factors in the Pakistani population over a 20-year period. We systematically reviewed research articles published in English (2000−2020) from PubMed and Google Scholar. The search results 26 publications involving 10,924 people and 2611 seropositive cases. The toxoplasmosis seropositivity rate was higher in women (25.44%) as compared to men (21.48%) and were statistically significant (p < 0.001). Furthermore, seropositivity was high among people with direct contact with cats, who consumed uncooked meat and raw vegetables, had poor education, and lived in rural areas. The 35−65-year age group had the highest prevalence rate of T. gondii infection. Toxoplasma infection was significantly more prevalent in Khyber Pakhtunkhwa province (25.87%) than in Punjab (20.42%) (p < 0.001). This is the first comprehensive analysis of T. gondii infection epidemiology in Pakistan. It reveals a high frequency of infection among women. We strongly encourage further research to aid patient care and the development of more efficient diagnostic tests and preventative techniques.

A Review on Alaria alata, Toxoplasma gondii and Sarcocystis spp. in Mammalian Game Meat Consumed in Europe: Epidemiology, Risk Management and Future Directions

Simple Summary

In many European countries, game meat consumption is related to the traditional hunting culture. Its demand and consumption are increasing, also due to the growing populations of wild ungulates. However, specific public health issues exist and should be taken into account. This review focuses on the causal agents, epidemiology, potential risk for human health and its management along the supply chain, including parasite detection at slaughtering and inactivation in meat, of three parasites (Alaria alata, Toxoplasma gondii and Sarcocystis spp.), which can be transmitted by the main mammalian game meat species in the EU: wild boar (Sus scrofa), red deer (Cervus elaphus), roe deer (Capreolus capreolus), fallow deer (Dama dama), Alpine chamois (Rupicapra rupicapra), moose (Alces alces), hare (Lepus europaeus) and wild rabbit (Oryctolagus cuniculus). By presenting the main issues and knowledge gaps, this study aims to contribute to an improved control supporting the risk analysis process.

Abstract

Game meat is increasingly appreciated and consumed in Europe, also due to the growing population of wild ungulates. In addition to interesting nutritional properties and market opportunities, game meat is characterized by some specific public health issues. This review focuses on the etiology, epidemiology, public health aspects and risk management along the supply chain, including parasite detection at slaughtering and inactivation in meat, of three selected foodborne parasitic hazards (Alaria alata, Toxoplasma gondii and Sarcocystis spp.) in the main mammalian game meat species in the EU: wild boar (Sus scrofa), red deer (Cervus elaphus), roe deer (Capreolus capreolus), fallow deer (Dama dama), Alpine chamois (Rupicapra rupicapra), moose (Alces alces), hare (Lepus europaeus) and wild rabbit (Oryctolagus cuniculus). The presented data point out the main issues, and knowledge gaps as well as the potential for improved control in order to contribute to the risk analysis process. To pursue an effective management of these parasitic zoonoses, awareness raising should involve all figures in the supply chain, including hunters, restaurateurs and consumers. Human behaviour and the lack of knowledge regarding meat borne parasitic zoonoses and the health risks they pose seem to be the most important factors responsible for human infections. However, detection methods, starting from the sampling procedure, should be further developed and standardized in order to improve the collection of accurate and up-to-date epidemiological data.

Oral Immunization With a Plant HSP90-SAG1 Fusion Protein Produced in Tobacco Elicits Strong Immune Responses and Reduces Cyst Number and Clinical Signs of Toxoplasmosis in Mice

Plant 90kDa heat shock protein (HSP90) is a potent adjuvant that increases both humoral and cellular immune responses to diverse proteins and peptides. In this study, we explored whether Arabidopsis thaliana HSP90 (AtHsp81.2) can improve the immune effects of a Toxoplasma gondii surface antigen 1 (SAG1). We designed two constructs containing the sequence of mature antigen (SAG1m), from aa77 to aa322, and B- and T-cell antigenic epitope-containing SAG1HC, from aa221 to aa319 fused to AtHsp81.2 sequence. When comparing the transient expression in Nicotiana tabacum X-27-8 leaves, which overexpress the suppressor helper component protease HC-Pro-tobacco etch virus (TEV), to that in N. benthamiana leaves, co-agroinfiltrated with the suppressor p19, optimal conditions included 6-week-old N. benthamiana plants, 7-day time to harvest, Agrobacterium tumefaciens cultures with an OD600nm of 0.6 for binary vectors and LED lights. While AtHsp81.2-SAG1m fusion protein was undetectable by Western blot in any of the evaluated conditions, AtHsp81.2-SAG1HC was expressed as intact fusion protein, yielding up to 90μg/g of fresh weight. Besides, the AtHsp81.2-SAG1HC mRNA was strongly expressed compared to the endogenous Nicotiana tabacum elongation factor-alpha (NtEFα) gene, whereas the AtHsp81.2-SAG1m mRNA was almost undetectable. Finally, mice were orally immunized with AtHsp81.2-SAG1HC-infiltrated fresh leaves (plAtHsp81.2-SAG1HC group), recombinant AtHsp81.2-SAG1HC purified from infiltrated leaves (rAtHsp81.2-SAG1HC group), non-infiltrated fresh leaves (control group), or phosphate-buffered saline (PBS group). Serum samples from plAtHsp81.2-SAG1HC-immunized mice had significantly higher levels of IgGt, IgG2a, and IgG2b anti-SAG1HC antibodies than serum from rAtHsp81.2-SAG1HC, control, and PBS groups. The number of cysts per brain in the plAtHsp81.2-SAG1HC-immunized mice was significantly reduced, and the parasite load in brain tissue was also lower in this group compared with the remaining groups. In an immunoblot assay, plant-expressed AtHsp81.2-SAG1HC was shown to react with antibodies present in sera from T. gondii-infected people. Therefore, the plant expression of a T. gondii antigen fused to the non-pathogenic adjuvant and carrier plant HSP90 as formulations against T. gondii can improve the vaccine efficacy, and plant extract can be directly used for vaccination without the need to purify the protein, making this platform a suitable and powerful biotechnological system for immunogenic antigen expression against toxoplasmosis.

Antenatal factors related to congenital toxoplasmosis in Rio De Janeiro, Brazil

BACKGROUND

Toxoplasmosis is one of the main preventable congenital infections in Brazil. This manuscript aims to describe antenatal factors possibly associated with congenital toxoplasmosis (CT).

METHODS

This is a case-control study, with data collected from medical records, from infants admitted under one year of age at the Infectious Diseases Clinic of Instituto de Puericultura e Pediatria Martagão Gesteira, reference center from Rio de Janeiro, exposed to toxoplasmosis during their antenatal period. Patients diagnosed with CT were classified as cases and those exposed without infection as controls.

RESULTS

A total of 289 patients were followed up in 10 years. CT was confirmed in 43 (14.9%) of which six (14%) were asymptomatic, five (12%) had the classic triad (retinochoroiditis, hydrocephalus and intracranial calcifications), 27/42 (64.3%) had reactive IgM. Even after adjusted for prematurity, cases were born with lower weight (OR 0.49 - IC95% 0.33-0.73). There was a 13% increase in chance of CT per gestational week of the maternal diagnosis. Maternal fever, consumption of poorly washed vegetables during pregnancy, and diagnosis in the third trimester were associated with CT (OR: 6.43, 6.55, and 2.16, respectively).

CONCLUSION

Fever during pregnancy, consumption of poorly washed vegetables and diagnosis in the third trimester were associated with CT. Infants with diagnosis of CT were born with lower weight than the controls.

Seroprevalence and Associated Risk Factors for Toxoplasma gondii Infections Among Urban Poor Communities in Peninsular Malaysia

PURPOSE

Toxoplasmosis is a zoonotic infection linked to compromised hygiene and sanitation via the handling of infected cat faeces, eating undercooked contaminated meat or transplacental transmission. We conducted a study to determine seroprevalence and risk factors associated with toxoplasmosis among the urban poor communities in Malaysia.

METHODS

The demographic profiles for each participant were obtained through a questionnaire survey prior to blood collection. A total of 389 participants were recruited and blood samples screened for the presence of anti-Toxoplasma IgG and IgM antibody using an ELISA commercial kit, SERION ELISA classic Toxoplasma gondii IgG and IgM.

RESULTS

The overall T. gondii seroprevalence was 69.6% with 56.8% seropositive for anti-Toxoplasma IgG, 7.7% seropositive for anti-Toxoplasma IgM and 5.1% seropositive for both IgG and IgM antibodies. The presence of both antibody classes in blood samples indicated high avidity, suggesting latent infection. Univariate analysis revealed significant associations that included; age, ethnicity, location and employment status while, significant lifestyle factors included source of drinking water and eating style. A multifactorial statistical model that incorporated all the significant effects from the first-stage univariate analyses listed above revealed that age and ethnicity were the two dominant and independent effects on IgG seroprevalence. For seroprevalence of IgM, the multifactorial model revealed a significant interaction between work and accommodation. IgM seroprevalence was higher among the unemployed inhabitants of PPR (Program Perumahan Rakyat) than those living in non-PPR accommodation, and higher than among the employed irrespective of their accommodation.

CONCLUSION

High seroprevalence of Toxoplasmosis in the community calls for increased awareness of disease transmission and improvements in hygiene and sanitation.

An analytical study on the awareness and practice relating toxoplasmosis among pregnant women in Casablanca, Morocco

BACKGROUND

Although toxoplasmosis is asymptomatic in most cases among pregnant women, it may cause newborn abortions and birth defects if the infection occurs during pregnancy. Therefore, raising awareness and promoting good practices of pregnant women towards toxoplasmosis disease is essential to avoid infection during pregnancy. The aim of this cross-sectional study is to assess toxoplasmosis awareness and its risk-related behavior pregnant women who attended public health centers in one of the biggest Moroccan cities: Casablanca.

METHODS

A structured questionnaire was used to collect data including socio-demographics data, awareness of etiology, modes of transmission and preventive practices towards toxoplasmosis.

RESULTS

This study survey showed that among 390 pregnant women interviewed, 41.2% reported having heard or read information regarding toxoplasmosis. Only 8.1% of them knew that toxoplasmosis is a parasitic disease caused by Toxoplasma gondii, and 13.7% of those who gave a correct answer were aware that the host of toxoplasmosis is cats. There is a significant statistical association between age, level of education and profession of pregnant women and toxoplasmosis awareness. Despite of the majority of the interviewed pregnant women had had effective preventive practices towards toxoplasmosis, 17.4% of pregnant women were convinced that Toxoplasmosis can transmit to the fetus and 14.3% stated it is asymptomatic in most cases.

CONCLUSION

This study highlights the low level of knowledge and awareness of toxoplasmosis among pregnant women in Casablanca/Morocco. Therefore, a special education program targeting all women during their reproductive age is necessary.

Male-to-Female Presumed Transmission of Toxoplasmosis Between Sexual Partners

Toxoplasmosis is one of the most widespread human parasitoses in developed countries. Sexual transmission has been confirmed in several animal species, and indirect evidence suggests it may occur in humans. We compared the seropositivity to Toxoplasma gondii in couples who visited the Center for Assisted Reproduction in Prague from June 2016 to June 2018 and analyzed various risk factors including the serological status of sexual partner. By comparing the risk factors in men and women, we tested the hypothesis of male-to-female sexual transmission of toxoplasmosis. The prevalence of toxoplasmosis in women with infected male partners (25.6%; n = 156) was higher than in women with uninfected male partners (18.2%; n = 477; P = 0.045). Therefore, a partner's seropositivity seems to be a risk factor for infection in women (n = 593; prevalence ratio = 1.418; P = 0.045) but not in men (n = 573; prevalence ratio = 1.058; P = 0.816). Our results support the hypothesis of the sexual transmission of T. gondii from men to women. The risk may seem relatively low, but transmission can occur during unprotected sexual intercourse, which may be at the time of conception. Because of the risk of congenital toxoplasmosis, a lower risk of infection than that observed in our study can represent a serious health problem.

Occurrence of Toxoplasma gondii on Raw Leafy Vegetables in Gaza, Palestine

ABSTRACT

Toxoplasma gondii, a ubiquitous obligate intracellular parasite that can infect homeothermic animals, is one of the main pathogens causing foodborne diseases worldwide. In Gaza, Palestine, leafy vegetables are frequently eaten raw. The present study was carried out to investigate the occurrence of T. gondii oocyst in local leafy vegetables. Fifty samples each of six species of leafy plants sold in open-air markets, in supermarkets, and by retail sellers were randomly collected from March to August 2019, for a total of 300 samples. The samples were examined by light microscopy after flotation in Sheather's sucrose solution and by PCR assay of the pelleted samples. All suspect T. gondii oocysts were confirmed with a PCR assay. With the PCR assay of the pelleted samples, only 19 (6.33%) of the 300 samples were positive for T. gondii, whereas with the Sheather's flotation method, 35 (11.66%) of the 300 samples were positive. With the PCR assay, among the six plant types mint had the highest T. gondii prevalence (10.00% of samples) followed by watercress and dill (both 8.00%), parsley (6.00%), thyme (4.00%), and lettuce (2.00%). Even though the relative prevalence of T. gondii in the contaminated plant species was similar with both the PCR and Sheather's flotation methods, the actual prevalences were different. With Sheather's flotation, T. gondii prevalence was highest in mint (18.00% of samples) followed by watercress (14.00%), dill (13.00%), parsley (10.00%), thyme (10.00%), and lettuce (6.00%). The relationship between T. gondii contamination and the time of year the samples were collected was also significant. The highest prevalence recorded was in July followed by June and August. These findings indicate that leafy vegetables, particularly mint, can be contaminated with T. gondii and are a potential risk factor for transmitting T. gondii to humans in Gaza, Palestine.

HIGHLIGHTS

Seroepidemiology and Associated Risk Factors of Toxoplasma gondii in Hemodialysis Patients

PURPOSE

Immunocompromised patients may be at risk for reactivation of the toxoplasmosis infection, because of defection in cell-mediated immunity. Therefore, early diagnosis would be highly desirable in these individuals. This case-control study was designed to increase information about toxoplasmosis in hemodialysis (HD) patients in Guilan province, Iran.

METHODS

The study was performed among 150 patients and 150 controls referred to hospitals of Guilan University of Medical Sciences during 2018-2019. Questionnaire forms, including demographic and epidemiological information, were completed. Peripheral blood samples were taken for serum separation and were collected into tubes and then kept at - 20 °C until use. IgG and IgM antibodies to Toxoplasma gondii were detected by a commercial ELISA kit. Accordingly, IgG absorbance levels < 9 were considered negative, 9-11 was considered borderline, and > 11 was positive; IgM absorbance levels < 0.9 were considered negative, 0.9-1.1 was assumed to be borderline, and > 1.1 was positive.

RESULTS

Throughout the study, 72.0% of HD patients and 64.7% of the control group were positive for anti-Toxoplasma IgG antibody subsequently. 2% of HD patients and 0.7% of the control group were positive for anti-Toxoplasma IgM antibody and these difference weren't significant between control and ones with HD (P > 0.05). There was no significant difference between dialysis duration factor and the seropositivity rate. Seroprevalence of T. gondii infection did not vary significantly with age, educational level, residence and presence of a cat at home. On the contrary, seroprevalence varied significantly with gender and consumption of raw vegetables.

CONCLUSION

Because of the high percentage of positivity for Toxoplasma IgG antibodies in hemodialysis patients, we suggest a periodically screening program to carry out for monitoring and evaluating the possible dissemination of toxoplasmosis during hemodialysis.

Human toxoplasmosis in Mozambique: gaps in knowledge and research opportunities

Toxoplasmosis is a parasitic zoonotic disease caused by Toxoplasma gondii that afflicts humans worldwide and wild and domestic warm-blooded animals. In immunocompetent individuals, the acute phase of infection presents transient low or mild symptoms that remain unnoticed. In immunocompromised patients, T. gondii is a life-threatening opportunistic infection, which can result from the reactivation of latent infection or primary infection. Moreover, congenital toxoplasmosis, which results from the transplacental passage of tachyzoites into the fetus during a pregnant primary infection, can lead to miscarriage, stillbirth, or ocular and neurologic disease, and neurocognitive deficits in the newborns. Thus, the present review aims to address the current knowledge of T. gondii infection and toxoplasmosis in Africa and especially in Mozambique, stressing the importance of identifying risk factors and promote awareness among the health care providers and population, assessing the gaps in knowledge and define research priorities. In Mozambique, and in general in southern African countries, clinical disease and epidemiological data have not yet been entirely addressed in addition to the implications of T. gondii infection in immunocompetent individuals, in pregnant women, and its relation with neuropsychiatric disorders. The main gaps in knowledge in Mozambique include lack of awareness of the disease, lack of diagnostic methods in health facilities, lack of genetic data, and lack of control strategies.

Serosurvey of Anti-Toxoplasma gondii Antibodies in Homeless Persons of São Paulo City, Southeastern Brazil

Seroprevalence of Toxoplasma gondii has been extensively studied in a variety of different human populations. However, no study has focused on homeless populations. Accordingly, the present study aimed to assess the seroprevalence of anti-T. gondii antibodies and the risk factors associated in homeless persons from homeless shelter of São Paulo city, southeastern Brazil. In addition, anti-HIV antibodies and associated risk of T. gondii and HIV coinfection have been evaluated. Anti-T. gondii antibodies were detected by indirect fluorescent antibody test. In addition, anti-HIV levels were tested by chemiluminescence enzyme immunoassay, with positive samples confirmed by rapid immunoblot assay. Overall, IgG anti-T. gondii seropositivity was found in 43/120 (35.8%) homeless persons, with endpoint titers varying from 16 to 1,024. The only two pregnant women tested were negative for IgM by chemiluminescence enzyme immunoassay, with normal parturition and clinically healthy newborns in both cases. There were no statistical differences in the risk factors for anti-T. gondii serology (p > 0.05). Anti-HIV seropositivity was found in 2/120 (1.7%) homeless persons, confirmed as HIV-1. One HIV seropositive individual was also sero-reactive to IgG anti-T. gondii, and both were negative to IgM anti-T. gondii. This is the first study that reports the serosurvey of T. gondii in homeless persons worldwide. Despite the limited sample size available in the present study, our findings have shown that the prevalence of anti-T. gondii antibodies in homeless persons herein was lower than the general population, probably due to homeless diet habit of eating mainly processed food intake. No statistical differences were found regarding risk factors for anti-T. gondii exposure in homeless persons. Future studies should be conducted to fully establish risk factors for anti-T. gondii exposure in homeless persons.

Determination of the viability of Toxoplasma gondii oocysts by PCR real-time after treatment with propidium monoazide

This study aimed to investigate a methodology for discriminating viable and non-viable T. gondii oocysts in water. Analyses included two steps: (i) microscopic investigation with vital dyes; (ii) molecular investigation, using a real time PCR (qPCR), after parasite treatment (or not) with propidium monoazide (PMA). The method was called qPCR-PMA. Oocyst aliquots were incubated (15 min) at 25 ºC or 100 ºC and analyzed by microscopy, after trypan blue and neutral red staining. Microscopic investigation determined viable and non-viable oocysts. For the molecular investigation, both aliquots of oocysts were treated with PMA. Non-viable oocysts, after PMA treatment, exhibited an inhibition of DNA amplification by qPCR. Although analyses were carried out with oocysts treated experimentally, these results suggest that qPCR-PMA can be a useful strategy to distinguish viable and non-viable T. gondii oocysts in water safety testing, showing if water is safe to drink.

Seroprevalence of Anti-Toxoplasma gondii Antibodies and Associated Factors Among Pregnant Women Attending Antenatal Care at Debre Markos Referral Hospital, Northwest Ethiopia

Background

Toxoplasma gondii is an obligate intracellular protozoan parasite that causes a zoonotic disease called toxoplasmosis. If the infection acquired during pregnancy is not detected and treated early, the parasite can be transmitted transplacentally to the fetus, resulting in congenital toxoplasmosis, which likely leads to serious consequences in the fetus. Toxoplasmosis constitutes a major public health problem particularly in low- and middle-income countries including Ethiopia. This study aimed to determine the seroprevalence and to assess the potential risk factors of toxoplasmosis among pregnant women attending antenatal care at Debre Markos Referral Hospital, Northwest Ethiopia.

Methods

In this cross-sectional study, data on the sociodemographic and potential obstetric and behavioral risk factors were gathered through pretested structured questionnaires, and 3 mL of venous blood was also drawn from each of randomly selected 233 study subjects. The serum samples were separated from the blood samples and tested for anti-Toxoplasma antibody using Toxo-latex slide agglutination test. Logistic regression analysis was used to examine the association between risk factors considered and T gondii infection.

Results

The overall prevalence of T gondii infection was 67.8%, indicating a high prevalence of toxoplasmosis in the study area. In multivariate analysis, keeping domestic cat at home was found to be the only explanatory variable of toxoplasmosis (adjusted odds ratio = 2.449, 95% confidence interval = 1.183-5.070, P = .016). All sociodemographic variables and most of the potential obstetric and behavioral risk factors were not statistically significant explanatory variables of T gondii infection.

Conclusion

The prevalence of toxoplasmosis is high in the study area. Thus, pregnant women should be aware of the potential risk of the disease when keeping cats at home and management of their litter. Inclusion of serologic screening for T gondii infection at antenatal care is warranted for prevention of congenital toxoplasmosis.

Use of Veterinary Vaccines for Livestock as a Strategy to Control Foodborne Parasitic Diseases

Foodborne diseases (FBDs) are a major concern worldwide since they are associated with high mortality and morbidity in the human population. Among the causative agents of FBDs, Taenia solium, Echinococcus granulosus, Toxoplasma gondii, Cryptosporidium spp., and Trichinella spiralis are listed in the top global risk ranking of foodborne parasites. One common feature between them is that they affect domestic livestock, encompassing an enormous risk to global food production and human health from farm to fork, infecting animals, and people either directly or indirectly. Several approaches have been employed to control FBDs caused by parasites, including veterinary vaccines for livestock. Veterinary vaccines against foodborne parasites not only improve the animal health by controlling animal infections but also contribute to increase public health by controlling an important source of FBDs. In the present review, we discuss the advances in the development of veterinary vaccines for domestic livestock as a strategy to control foodborne parasitic diseases.

Seroprevalence and Risk Factors of Toxoplasma gondii Infection in Pregnant Women from Western Romania

Seroprevalence and risk factors of Toxoplasma gondii infection were assessed among pregnant women in Western Romania. T. gondii seroprevalence was evaluated in 208 pregnant women by demonstration of serum antibodies using the commercial Vitros anti-Toxoplasma immunoglobulin G (IgG) and IgM assays. A questionnaire was administered to obtain information regarding the risk factors associated with T. gondii seropositivity. Chi-squared tests, Fisher exact test, and Stata 9.2 (Statacorp, Texas) were used to evaluate differences between T. gondii positive and negative women. T. gondii antibodies were demonstrated in 116 (55.8%) of 208 pregnant women. Lower level of education and working with meat were found to be risk factors for T. gondii seropositivity. Pet owners (cats and/or dogs) had a higher T. gondii seroprevalence than those who did not report having any pet (p = 0.032). Women with ≥4 live births were more frequently T. gondii seropositive than those without previous births (p < 0.002). Women with histories of spontaneous abortions were more frequently T. gondii seropositive than those without such a history (p = 0.036). Our results indicate a high prevalence of T. gondii antibodies in pregnant women in Romania. Risk factors for T. gondii past infection were being in the older age group, working with meat, having pets, a lower level of education, higher gravidity, and history of spontaneous abortions. This survey provided the first data regarding risk factors for T. gondii infection in pregnant women from Western Romania.

Patterns of Transmission and Sources of Infection in Outbreaks of Human Toxoplasmosis

We report on apparent temporal progression of probable sources of infection and transmission routes for global human toxoplasmosis outbreaks as described in published articles. We searched the Scientific Electronic Library Online, Web of Science, PubMed, and Scopus databases for articles on Toxoplasma, toxoplasmosis, and outbreaks. We found that transmission routes for Toxoplasma gondii varied by decade. In the 1960s and 1990s, toxoplasmosis outbreaks mainly occurred through ingestion of cysts in meat and meat derivatives; in the 1980s, through milk contaminated with tachyzoites; in 2000, due to the presence of oocysts in water, sand, and soil; and in 2010, due to oocysts in raw fruits and vegetables. Our study suggests a possible change in the epidemiology of reported toxoplasmosis outbreaks. Because of this change, we suggest that greater attention be paid to the disinfection of vegetables, as well as to the quality of water used for drinking and irrigation.

First Age- and Gender-Matched Case-Control Study in Australia Examining the Possible Association between Toxoplasma gondii Infection and Type 2 Diabetes Mellitus: The Busselton Health Study

An emerging field of research is starting to examine the association of infectious pathogens with type 2 diabetes mellitus (T2DM). An understudied parasite of interest is Toxoplasma gondii. Globally, very few studies have been conducted to investigate this association. Additionally, very little data exists on the prevalence of T. gondii in the general Australian population. Our group sought to determine the prevalence, association, and risk factors between T. gondii infection and T2DM from a representative Australian human population. Through a cross-sectional, age- and gender-matched case-control study, 150 subjects with T2DM together with 150 control subjects from the Busselton Health Study cohort were investigated. Sera samples were tested for the presence of anti-T. gondii IgG and IgM antibodies using enzyme-linked immunosorbent assays. Survey-derived data were also analyzed to evaluate associated risk factors. The IgG seroprevalence was found to be 62% and 66% for the T2DM and control groups, respectively (OR : 0.84; p = 0.471). IgM antibodies were detected in 5% of the T2DM patients and in 10% of the controls (OR = 0.51; p = 0.135). There were no significant differences between male and female IgG seroprevalence rates for both groups (OR : 0.88, 0.80; p = 0.723). The IgG seropositivity rate increased significantly in T2DM patients aged 45-84 years in comparison to those aged 18-44 years (p < 0.05), but this was not observed in the control subjects. No risk factors were associated with T. gondii seropositivity in both groups. The first Australian study of its kind found T. gondii infection in Western Australia to be highly prevalent. The results also showed that there is no serological evidence of an association between T. gondii infection and T2DM in the studied subjects. Australian health authorities should focus on raising awareness of toxoplasma infection and target T. gondii transmission control. Further studies are needed to clarify the role of T. gondii in T2DM.

Sero-epidemiological status and risk factors of toxoplasmosis in pregnant women in Northern Vietnam

Background

In Vietnam, few studies have determined the epidemiological status of toxoplasmosis in pregnant women and no routine prenatal screening is in place. This study was conducted to evaluate the seroprevalence of this zoonotic parasitic infection in pregnant women in Northern Vietnam and to assess the association with awareness, risk factors and congenital toxoplasmosis.

Methods

Approximately 800 pregnant women were included in the study from two hospitals, one in Hanoi and one in Thai Binh province, which is known to have a dense cat population. Serological immunoglobulin G (IgG) and immunoglobulin M (IgM) detection was performed to estimate the seroprevalence of toxoplasmosis and sero-incidence of maternal and congenital toxoplasmosis. In addition, a survey was conducted about awareness, clinical history, presentation of signs and symptoms relating to toxoplasmosis and to detect biologically plausible and socio-demographic risk factors associated with toxoplasmosis. Associations with seroprevalence were assessed using univariable and multivariable analysis.

Results

The mean IgG seroprevalence after the full diagnostic process was 4.5% (95% confidence interval(CI): 2.7–7.0) and 5.8% (95% CI: 3.7–8.6) in Hanoi and Thai Binh hospital, respectively, and included one seroconversion diagnosed in Thai Binh hospital. Only 2.0% of the pregnant women in Hanoi hospital and 3.3% in Thai Binh hospital had heard about toxoplasmosis before this study.

Conclusion

Since the percentage of seronegative, and thus susceptible, pregnant women was high and the awareness was low, we suggest to distribute information about toxoplasmosis and its prevention among women of child bearing age. Furthermore, future studies are recommended to investigate why such a low seroprevalence was seen in pregnant women in Northern Vietnam compared to other countries in South East Asia and globally.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-3885-7) contains supplementary material, which is available to authorized users.

Public health risks associated with food-borne parasites

Parasites are important food‐borne pathogens. Their complex lifecycles, varied transmission routes, and prolonged periods between infection and symptoms mean that the public health burden and relative importance of different transmission routes are often difficult to assess. Furthermore, there are challenges in detection and diagnostics, and variations in reporting. A Europe‐focused ranking exercise, using multicriteria decision analysis, identified potentially food‐borne parasites of importance, and that are currently not routinely controlled in food. These are Cryptosporidium spp., Toxoplasma gondii and Echinococcus spp. Infection with these parasites in humans and animals, or their occurrence in food, is not notifiable in all Member States. This Opinion reviews current methods for detection, identification and tracing of these parasites in relevant foods, reviews literature on food‐borne pathways, examines information on their occurrence and persistence in foods, and investigates possible control measures along the food chain. The differences between these three parasites are substantial, but for all there is a paucity of well‐established, standardised, validated methods that can be applied across the range of relevant foods. Furthermore, the prolonged period between infection and clinical symptoms (from several days for Cryptosporidium to years for Echinococcus spp.) means that source attribution studies are very difficult. Nevertheless, our knowledge of the domestic animal lifecycle (involving dogs and livestock) for Echinoccocus granulosus means that this parasite is controllable. For Echinococcus multilocularis, for which the lifecycle involves wildlife (foxes and rodents), control would be expensive and complicated, but could be achieved in targeted areas with sufficient commitment and resources. Quantitative risk assessments have been described for Toxoplasma in meat. However, for T. gondii and Cryptosporidium as faecal contaminants, development of validated detection methods, including survival/infectivity assays and consensus molecular typing protocols, are required for the development of quantitative risk assessments and efficient control measures.

Use of lectin-magnetic separation (LMS) for detecting Toxoplasma gondii oocysts in environmental water samples

Proof-of-principle of lectin-magnetic separation (LMS) for isolating Toxoplasma oocysts (pre-treated with 0.5% acidified pepsin (AP)) from water for subsequent detection by microscopy or molecular methods has been shown. However, application of this technique in the routine water-analysis laboratory requires that the method is tested, modified, and optimized. The current study describes attempts to apply the LMS technique on supernatants from water samples previously analyzed for contamination with Cryptosporidium and Giardia using standard methods, and the supernatant following immunomagnetic separation (IMS) retained. Experiments on AP-treatment of Toxoplasma oocysts in situ in such samples demonstrated that overnight incubation at 37 °C was adequate, but excess AP had to be removed before continuing to LMS; neutralization in sodium hydroxide and a single wash step was found to be suitable. Mucilaginous material in post-IMS samples that had been stored at room temperature without washing, which was found to be probably an exudate from bacterial and fungal overgrowth, hampered the isolation of T. gondii oocysts by LMS beads. For detection, microscopy was successful only for clean samples, as debris occluded viewing in dirtier samples. Although qPCR was successful, for some samples non-specific inhibition occurred, as demonstrated by inhibition of an internal amplification control in the qPCR reaction. For some, but not all, samples this could be addressed by dilution. Finally, the optimized methodology was used for a pilot project in which 23 post-IMS water sample concentrates were analyzed. Of these, only 20 provided interpretable results (without qPCR inhibition) of which one sample was positive, and confirmed by sequencing of PCR product, indicating that Toxoplasma oocysts occur in Norwegian drinking water samples. In conclusion, we suggest that post-IMS samples may be suitable for analysis for Toxoplasma oocysts using LMS, only if freshly processed or washed before being refrigerated. In addition, application of AP treatment requires a neutralization step before proceeding to LMS. For detection, qPCR, rather than microscopy, is the most appropriate approach, although some inhibition may still occur, and therefore inclusion of an internal amplification control is important. Our study indicates that, despite some limitations, this approach would be appropriate for further large-scale analysis of samples of raw and treated drinking water.

Toxoplasma gondii in the Food Supply

Toxoplasmosis is caused by infection with the protozoan parasite Toxoplasma gondii. Infections are usually either asymptomatic or develop mild symptoms that are self-limited, but infections in immunosuppressed persons can be severe. Infections in pregnant women can cause serious health problems in the child such as mental retardation and blindness. Infection with T. gondii in immunocompetent adults can lead to impaired eyesight. Toxoplasmosis has ranked very highly in two studies of death and disability attributable to foodborne pathogens. The consumption of raw or undercooked meat containing T. gondii tissue cysts and the consumption of raw vegetables or water contaminated with T. gondii oocysts from cat feces is most frequently associated with human illness. The risk of acquiring a Toxoplasma infection via food varies with cultural and eating habits in different human populations.

Socio-demographic determinants of Toxoplasma gondii seroprevalence in migrant workers of Peninsular Malaysia

BACKGROUND

The number of migrants working in Malaysia has increased sharply since the 1970's and there is concern that infectious diseases endemic in other (e.g. neighbouring) countries may be inadvertently imported. Compulsory medical screening prior to entering the workforce does not include parasitic infections such as toxoplasmosis. Therefore, this study aimed to evaluate the seroprevalence of T. gondii infection among migrant workers in Peninsular Malaysia by means of serosurveys conducted on a voluntary basis among low-skilled and semi-skilled workers from five working sectors, namely, manufacturing, food service, agriculture and plantation, construction and domestic work.

METHODS

A total of 484 migrant workers originating from rural locations in neighbouring countries, namely, Indonesia (n = 247, 51.0%), Nepal (n = 99, 20.5%), Bangladesh (n = 72, 14.9%), India (n = 52, 10.7%) and Myanmar (n = 14, 2.9%) were included in this study.

RESULTS

The overall seroprevalence of T. gondii was 57.4% (n = 278; 95% CI: 52.7-61.8%) with 52.9% (n = 256; 95% CI: 48.4-57.2%) seropositive for anti-Toxoplasma IgG only, 0.8% (n = 4; 95% CI: 0.2-1.7%) seropositive for anti-Toxoplasma IgM only and 3.7% (n = 18; 95% CI: 2.1-5.4%) seropositive with both IgG and IgM antibodies. All positive samples with both IgG and IgM antibodies showed high avidity (> 40%), suggesting latent infection. Age (being older than 45 years), Nepalese nationality, manufacturing occupation, and being a newcomer in Malaysia (excepting domestic work) were positively and statistically significantly associated with seroprevalence (P < 0.05).

CONCLUSIONS

The results of this study suggest that better promotion of knowledge about parasite transmission is required for both migrant workers and permanent residents in Malaysia. Efforts should be made to encourage improved personal hygiene before consumption of food and fluids, thorough cooking of meat and better disposal of feline excreta from domestic pets.

Predictors of Toxoplasma gondii infection in Czech and Slovak populations: the possible role of cat-related injuries and risky sexual behavior in the parasite transmission

The protozoan Toxoplasma gondii infects about one-third of the world's population. The consumption of raw meat, contact with cats, contact with soil, and ingestion of food or water contaminated with soil are considered to be the most important sources of infection. Still in most women who were infected during pregnancy, no definitive source of infection is found. In 2014-2016, independent sources of T. gondii infection were searched for by gathering epidemiological data from 1865 (519 infected) responders. Touching garden soil (odds ratio (OR) 3·14, 95% confidence interval (CI) 1·3-6·35), sustaining cat-related injuries (OR 2·16, 95% CI 1·25-3·74), and eating improperly washed root vegetables (OR 1·71, 95% CI 1·02-2·87), but not risky sexual behavior (OR 1·22, 95% CI 0·79-1·90), were the predictors of infection. The seroprevalence of T. gondii infection had been increasing up to ages 35-50 in men and ages 50-54 in women. Past those ages, seroprevalence of toxoplasmosis has been decreasing. This suggests that the natural decrease of anamnestic antibodies concentrations over time leads to positivity-to-negativity seroconversion in many subjects. If this is true, then the prevalence of T. gondii infection in a general population and its potential impacts on public health could be much larger than generally believed.

Seroprevalence and potential risk factors of T. gondii infection in pregnant women attending antenatal care at Bonga Hospital, Southwestern Ethiopia

OBJECTIVES

To determine the seroprevalence and associated risk factors of T.gondii infection in pregnant women attending antenatal care at Bonga Hospital, Southwestern Ethiopia.

METHODS

A cross-sectional study was carried out from February to May 2016. Systematic sampling technique was used to collect sera from 210 pregnant women. Sample was tested for anti-T.gondii- antibodies by Latex Agglutination Test (LAT). Risk factors associated with T.gondii infection in pregnant women was assessed through structured questionnaire. Univariate and multivariate logistic regression analysis was used to check association of T.gondii infection with different risk factors using SPSS version 20.

RESULTS

The overall seroprevalence of T.gondii infection in pregnant women was 75.7% (95% CI: 69.9-81.5). Multivariate logistic regression analysis indicated that the odds of T.gondii infection was higher in pregnant women between age range of 36-44 (AOR=2.82; 95% CI:1.2-7.82; P=0.031), in multigravidae (AOR=3.3; 95% CI:1.36-8.04; P=0.009), in those eating raw meat (AOR=5.1; 95% CI:2.22-11.68; P=0.000), in those eating raw vegetables (AOR=5.5; 95% CI:1.03-29.5; P=0.046), in those who have history of abortion (AOR=4.4;95% CI:1.10-17.49; P=0.036), in women who drink river/streams water (AOR=5; 95% CI: 1.67-15.44; P=0.004) and in those who didn't handle raw meat (AOR=2.4; 95% CI: 1-5.56; P=0.049).

CONCLUSION

The present result shows high seroprevalence of T.gondii infection in pregnant women. Public education on identified risk factors and screening of pregnant women during their antenatal care should be recommended.

Prevalence, incidence estimations, and risk factors of Toxoplasma gondii infection in Germany: a representative, cross-sectional, serological study

Representative data on the extent of endemicity, burden, and risk of human toxoplasmosis are scarce. We assessed the prevalence and determinants of seropositivity of Toxoplasma gondii among adult participants of a nationwide representative cross-sectional survey in Germany. Sera collected from a representative cohort of adults (age 18-79; n = 6,663) in Germany were tested for anti-T. gondii IgG antibodies. Interview-derived data were used to evaluate associated factors. Multivariable logistic regression was applied using sampling weights and accounting for survey design cluster effects. Seroprevalence increased from 20% (95%-CI:17-23%) in the 18-29 age group to 77% (95%-CI:73-81%) in the 70-79 age group. Male gender, keeping cats and BMI ≥30 were independent risk factors for seropositivity, while being vegetarian and high socio-economic status were negatively associated. Based on these data, we estimate 1.1% of adults and 1.3% of women aged 18-49 to seroconvert each year. This implies 6,393 seroconversions annually during pregnancies. We conclude that T. gondii infection in Germany is highly prevalent and that eating habits (consuming raw meat) appear to be of high epidemiological relevance. High numbers of seroconversions during pregnancies pose substantial risks for unborn children. Efforts to raise awareness of toxoplasmosis in public health programs targeting to T. gondii transmission control are therefore strongly advocated.

Toxoplasmosis-Related Knowledge and Preventive Practices among Undergraduate Female Students in Jordan

Foodborne toxoplasmosis is a leading cause of foodborne deaths and hospitalization worldwide. The level of exposure to Toxoplasma gondii is influenced by culture and eating habits. There is a scarcity of data about women's knowledge and perception of this disease. The aim of this study was to determine toxoplasmosis knowledge and preventive practices of young childbearing age women in Jordan. A descriptive cross-sectional study recruited a random sample of 1,390 undergraduate university female students and was stratified based on place of residency. About half of students (51.1%) reported having "ever" heard or read about toxoplasmosis, and almost all students (98.6%) had never been tested for toxoplasmosis. Overall, there was a lack of awareness about toxoplasmosis, its risk factors, symptoms, and timing of infection, and preventive practices. High percentages of females reported a high level of hygienic practices related to hand washing after gardening, changing cat litter, and handling raw meat. However, 16.7% of students reported eating raw meat, 26.5% usually eat traditional herbs, and 17.2% drink untreated spring water. This study establishes a baseline for the awareness levels about toxoplasmosis among young women in Jordan. These findings highlight the urgent need for toxoplasmosis awareness and preventive education for childbearing females. An effective education and outreach program should cover important topics concerning risk factors, high-risk foods, and preventive measures against toxoplasmosis.

Household practices related to disease transmission between animals and humans in rural Cambodia

BACKGROUND

Zoonotic diseases are disproportionately affecting poor societies in low-income countries and pose a growing threat to public health and global food security. Rural Cambodian households may face an increased likelihood of exposure to zoonotic diseases as people there live in close association with livestock. The objectives of the study was to identify practices known to influence zoonosis transmission in rural Cambodian households and relate the practices to agro-ecological region, socio-economic position, demographics, livestock management and zoonosis awareness.

METHODS

The study was conducted in three different agro-ecological regions of Cambodia; 10 villages each in the central lowlands, north-west wetlands and on the south coast, where information was obtained in questionnaires administered to 300 households, and 30 village heads and animal health workers.

RESULTS

Descriptive analysis revealed a gender difference in responsibility for livestock and that the main purpose of raising livestock was for sale. Few respondents (6%) perceived a likelihood of disease transmission in their village between livestock, humans and wildlife, despite household practices related to zoonosis transmission being common. More than one-forth of households practised behaviours such as culling sick animals for consumption, eating animals found dead and allowing animals to enter sleeping and food preparation areas. Associations between household practices and possible explanatory factors were analysed with multivariable models using generalised estimation equations to account for clustering of practices within villages. Factors found to influence household practices were agro-ecological region, socio-economic position, number of people in the household, livestock species reared and awareness of zoonoses.

CONCLUSIONS

Cambodia has experienced numerous fatal human cases of zoonotic influenza and extensive influenza information campaigns have been run, yet only a few of the households surveyed here reported the threat of zoonosis to be a concern in their village. Zoonosis awareness was positively related to hand washing behaviour, but other practices associated with an increased or decreased likelihood of exposure to zoonotic pathogens were unaffected by awareness. The findings indicate a knowledge-to-action gap among rural farmers and highlight the necessity for reconstructed interventions in zoonotic disease control.

Seroepidemiology and risk factors of Toxoplasma gondii infection in undergraduate university female students in Jordan

This study estimated the seroprevalence and risk factors for acquiring Toxoplasma gondii infection by undergraduate female university students in Jordan. A cross-sectional study from September 2013 to July 2014 analysed 202 blood samples for IgG and IgM antibodies by enzyme-linked immunosorbent assay and a semi-constructed questionnaire was completed by participants to gather information about Toxoplasma infection risk factors. T. gondii IgG antibodies were detected in 66.5% of the females. Only one sample was positive for both IgG and IgM. Using χ2 test, six factors showed significant association with T. gondii infection (P ⩽ 0.01). The multivariate logistic regression model showed that female students living in houses, wet areas, with income >US $750/month and using spring (untreated) water were 47.42, 10.20, 5.00, 3.25 more times at risk to be seropositive for T. gondii, respectively, compared to female students living in apartments, dry areas, with income ≤ US $750/month and using treated water, respectively. This study concluded that T. gondii infection in female university students in Jordan is high and most women become infected before marriage; however, congenital toxoplasmosis is still likely to occur in Jordan. Thus, dissemination of protective measures and knowledge by healthcare professionals is essential especially for pregnant women.

Toxoplasma gondii seroprevalence in wild boars (Sus scrofa) in Sweden and evaluation of ELISA test performance

Toxoplasma gondii is a zoonotic protozoan parasite, infecting a wide range of warm-blooded animals. The Swedish wild boar population is expanding and increased hunting provides its meat to a growing group of consumers. We performed a spatio-temporal investigation of T. gondii seroprevalence in Swedish wild boars. An ELISA was set up and evaluated against a commercial direct agglutination test, using Bayesian latent class analysis. The ELISA sensitivity and specificity were estimated to 79% and 85%, respectively. Of 1327 serum samples, 50% were positive. Thirty-four per cent of young wild boars and 55% of adults were positive (P < 0·001). The total seroprevalence ranged from 72% in 2005 to 38% in 2011 (P < 0·001), suggesting a declining trend. The highest seroprevalence, 65%, was recorded in South Sweden. In other regions it varied from 29% in Stockholm to 46% in East Middle Sweden.

Toxoplasmosis: an examination of knowledge among health professionals and pregnant women in a municipality of the State of Paraná

INTRODUCTION

The aim of this study was to investigate the knowledge of toxoplasmosis among professionals and pregnant women in the public health services in Paraná, Brazil.

METHODS

A cross-sectional observational and transversal study of 80 health professionals (44 nurses and 36 physicians) and 330 pregnant women [111 immunoglobulin M (IgM)- and IgG-non-reactive and 219 IgG-reactive] was conducted in 2010. An epidemiological data questionnaire was administered to the professionals and to the pregnant women, and a questionnaire about the clinical aspects and laboratory diagnosis of toxoplasmosis was administered to the professionals.

RESULTS

The participants frequently provided correct responses about prophylactic measures. Regarding the clinical and laboratory aspects, the physicians provided more correct responses and discussed toxoplasmosis with the pregnant women. The professionals had difficulty interpreting the avidity test results, and the physicians stated that they referred pregnant women with high-risk pregnancies to a county reference center. Of the professionals, 53 (91.4%) reported that they instructed women during prenatal care, but only 54 (48.6%) at-risk pregnant women and 99 (45.2%) women who were not at risk reported receiving information about preventive measures. The physicians provided verbal instructions to 120 (78.4%) women, although instructional materials were available in the county. The pregnant women generally lacked knowledge about preventive measures for congenital toxoplasmosis, but the at-risk pregnant women tended to respond correctly.

CONCLUSIONS

This study provides data to direct public health policies regarding the importance of updating the knowledge of primary care professionals. Mechanisms should be developed to increase public knowledge because prophylactic strategies are important for preventing congenital toxoplasmosis.

Toxoplasmosis--a global threat. Correlation of latent toxoplasmosis with specific disease burden in a set of 88 countries

BACKGROUND

Toxoplasmosis is becoming a global health hazard as it infects 30-50% of the world human population. Clinically, the life-long presence of the parasite in tissues of a majority of infected individuals is usually considered asymptomatic. However, a number of studies show that this 'asymptomatic infection' may also lead to development of other human pathologies.

AIMS OF THE STUDY

The purpose of the study was to collect available geoepidemiological data on seroprevalence of toxoplasmosis and search for its relationship with mortality and disability rates in different countries.

METHODS AND FINDINGS

Prevalence data published between 1995-2008 for women in child-bearing age were collected for 88 countries (29 European). The association between prevalence of toxoplasmosis and specific disease burden estimated with age-standardized Disability Adjusted Life Year (DALY) or with mortality, was calculated using General Linear Method with Gross Domestic Product per capita (GDP), geolatitude and humidity as covariates, and also using nonparametric partial Kendall correlation test with GDP as a covariate. The prevalence of toxoplasmosis correlated with specific disease burden in particular countries explaining 23% of variability in disease burden in Europe. The analyses revealed that for example, DALY of 23 of 128 analyzed diseases and disease categories on the WHO list showed correlations (18 positive, 5 negative) with prevalence of toxoplasmosis and another 12 diseases showed positive trends (p<0.1). For several obtained significant correlations between the seroprevalence of toxoplasmosis and specific diseases/clinical entities, possible pathophysiological, biochemical and molecular explanations are presented.

CONCLUSIONS

The seroprevalence of toxoplasmosis correlated with various disease burden. Statistical associations does not necessarily mean causality. The precautionary principle suggests however that possible role of toxoplasmosis as a triggering factor responsible for development of several clinical entities deserves much more attention and financial support both in everyday medical practice and future clinical research.

Seroprevalence and risk factors for Toxoplasma gondii infection among pregnant women in Northeast Iran

We report Toxoplasma IgG seroprevalence of 34.4% among 419 pregnant women in Mashhad, northeast Iran. Soil contact, living in rural environment, and level of education were associated with infection. The prevalence did not increase with age, suggesting high infection rate during childhood and adolescence.

Congenital toxoplasmosis in the state of Minas Gerais, Brazil: a neglected infectious disease?

This study aimed to investigate the distribution of congenital toxoplasmosis in the state of Minas Gerais, Southeastern Brazil and describe the demographic and socioeconomic profile of the municipalities associated with the disease. An ecological study was conducted using socioeconomic indicators of a database (MGSSRI) created by Fundação João Pinheiro (a government technical support agency of Minas Gerais), in order to show the development of the municipalities in the state. The prevalence of toxoplasmosis was the outcome and the items of the MGSSRI were the explanatory variables. Of 146,307 newborns screened (November 2006 to May 2007), 190 had congenital toxoplasmosis, yielding a prevalence of 1·3/1000, ranging from 0 to 76·9/1000 in the municipalities. The multivariate model indicated a higher occurrence of toxoplasmosis in municipalities with smaller populations and worse indexes of tax performance. Congenital toxoplasmosis appears to be a neglected disease in the state of Minas Gerais, given the high prevalence found and its concentration in municipalities with worse socioeconomic indexes.

Seroepidemiology of Toxoplasma gondii infection in women of child-bearing age in central Ethiopia

Background

Toxoplasma gondii infections during pregnancy can result in abortion or congenital defects. Prevalence and risk factors of toxoplasmosis in women of child-bearing age in Ethiopia are unknown. The current study was conducted with the objectives of estimating the seroprevalence and potential risk factors in acquiring T. gondii infection by women of child-bearing age in Central Ethiopia.

Methods

A cross-sectional study was conducted from March 2011 to September 2011. Sera of 425 women were analyzed by indirect enzyme linked immunosorbent assay (ELISA). A questionnaire survey was administered for all study participants to gather information on risk factors.

Results

The study revealed that anti- T. gondii IgG antibodies were detected in 81.4% of the samples of which 78.4% were positive for only IgG and 3.06% positive for both IgG and IgM antibodies. Seroprevalence of IgM antibodies to T. gondii (4.0%, 95% CI: 2.14, 5.86) was suggestive of recent infections. Of the 213 pregnant women 9 (4.2 %) were IgM reactive. Out of 17 potential risk factors investigated, univariate logistic regression showed significant association of T. gondii infection with study area, age, pregnancy status, raw vegetable consumption, source of water, presence of cats at home, contact with cats, HIV status and precaution during cats’ feces cleaning (P ≤ 0.05). The final logistic regression model revealed that: the probability of acquiring T. gondii infection by women of Debre-Zeit was 4.46 times (95% CI of adjusted odds ratio [aOR]: 1.67, 11.89; P =0.003) higher compared to women of Ambo, pregnant women were twice (95% CI aOR: 1.13, 3.59; P = 0.018) more likely to be seropositive than non-pregnant women and women who consume raw vegetable were at increased risk of infection (aOR = 2.21, 95% CI: 1.03, 4.78; P = 0.043) than women who didn’t consume.

Conclusion

The seroprevalence of T. gondii infection in women of child-bearing age in Central Ethiopia is high. Study area, pregnancy and raw vegetable consumption are risk factors to acquire T. gondii infection. Educational program, antenatal screening of pregnant women and further epidemiological studies to uncover the economic and health impact of toxoplasmosis are suggested.

How and why Toxoplasma makes us crazy

For a long time, a latent toxoplasmosis, the lifelong presence of dormant stages of Toxoplasma in various tissues, including the brain, was considered harmless for immunocompetent persons. Within the past 10 years, however, many independent studies have shown that this parasitic disease, with a worldwide prevalence of about 30%, could be indirectly responsible for hundreds of thousands of deaths due to its effects on the rate of traffic and workplace accidents, and also suicides. Moreover, latent toxoplasmosis is probably one of the most important risk factors for schizophrenia. At least some of these effects, possibly mediated by increased dopamine and decreased tryptophan, are products of manipulation activity by Toxoplasma aiming to increase the probability of transmission from intermediate to definitive host through predation.

Toxoplasma gondii infection in Kyrgyzstan: seroprevalence, risk factor analysis, and estimate of congenital and AIDS-related toxoplasmosis

Background

HIV-prevalence, as well as incidence of zoonotic parasitic diseases like cystic echinococcosis, has increased in the Kyrgyz Republic due to fundamental socio-economic changes after the breakdown of the Soviet Union. The possible impact on morbidity and mortality caused by Toxoplasma gondii infection in congenital toxoplasmosis or as an opportunistic infection in the emerging AIDS pandemic has not been reported from Kyrgyzstan.

Methodology/Principal Findings

We screened 1,061 rural and 899 urban people to determine the seroprevalence of T. gondii infection in 2 representative but epidemiologically distinct populations in Kyrgyzstan. The rural population was from a typical agricultural district where sheep husbandry is a major occupation. The urban population was selected in collaboration with several diagnostic laboratories in Bishkek, the largest city in Kyrgyzstan. We designed a questionnaire that was used on all rural subjects so a risk-factor analysis could be undertaken. The samples from the urban population were anonymous and only data with regard to age and gender was available. Estimates of putative cases of congenital and AIDS-related toxoplasmosis in the whole country were made from the results of the serology. Specific antibodies (IgG) against Triton X-100 extracted antigens of T. gondii tachyzoites from in vitro cultures were determined by ELISA. Overall seroprevalence of infection with T. gondii in people living in rural vs. urban areas was 6.2% (95%CI: 4.8–7.8) (adjusted seroprevalence based on census figures 5.1%, 95% CI 3.9–6.5), and 19.0% (95%CI: 16.5–21.7) (adjusted 16.4%, 95% CI 14.1–19.3), respectively, without significant gender-specific differences. The seroprevalence increased with age. Independently low social status increased the risk of Toxoplasma seropositivity while increasing numbers of sheep owned decreased the risk of seropositivity. Water supply, consumption of unpasteurized milk products or undercooked meat, as well as cat ownership, had no significant influence on the risk for seropositivity.

Conclusions

We present a first seroprevalence analysis for human T. gondii infection in the Kyrgyz Republic. Based on these data we estimate that 173 (95% CI 136–216) Kyrgyz children will be born annually to mothers who seroconverted to toxoplasmosis during pregnancy. In addition, between 350 and 1,000 HIV-infected persons are currently estimated to be seropositive for toxoplasmosis. Taken together, this suggests a substantial impact of congenital and AIDS-related symptomatic toxoplasmosis on morbidity and mortality in Kyrgyzstan.

A serological study on toxoplasmosis was undertaken in a rural and urban population in Kyrgyzstan. The observed seroprevalence was adjusted because of differences between age and gender stratifications in the study group compared to population census figures. This gave an estimated seroprevalence in rural and urban populations of 5.1% and 16.4% respectively. In our analysis we determined the risk-factors for infection in the rural population to be age, low social-status and low number of sheep owned. While the seroprevalence in this rural population was relatively low, the seroprevalence found in the urban population of Bishkek correlated better with international data. Extrapolating from our data, about 173 seroconversions during pregnancy may be expected annually in Kyrgyzstan. In addition, considering a prevalence of HIV-Toxoplasma-co-infection between 7/100,000 (official HIV-prevalence data) and 19.4/100,000 (UNAIDS-estimates), 350–1,000 people are at risk for AIDS-related toxoplasmosis. Therefore, in the face of the rising prevalence of HIV infection education of medical personnel on treatment and prevention of toxoplasmosis is recommended.

New approaches for the identification of drug targets in protozoan parasites

Antiparasitic chemotherapy is an important issue for drug development. Traditionally, novel compounds with antiprotozoan activities have been identified by screening of compound libraries in high-throughput systems. More recently developed approaches employ target-based drug design supported by genomics and proteomics of protozoan parasites. In this chapter, the drug targets in protozoan parasites are reviewed. The gene-expression machinery has been among the first targets for antiparasitic drugs and is still under investigation as a target for novel compounds. Other targets include cytoskeletal proteins, proteins involved in intracellular signaling, membranes, and enzymes participating in intermediary metabolism. In apicomplexan parasites, the apicoplast is a suitable target for established and novel drugs. Some drugs act on multiple subcellular targets. Drugs with nitro groups generate free radicals under anaerobic growth conditions, and drugs with peroxide groups generate radicals under aerobic growth conditions, both affecting multiple cellular pathways. Mefloquine and thiazolides are presented as examples for antiprotozoan compounds with multiple (side) effects. The classic approach of drug discovery employing high-throughput physiological screenings followed by identification of drug targets has yielded the mainstream of current antiprotozoal drugs. Target-based drug design supported by genomics and proteomics of protozoan parasites has not produced any antiparasitic drug so far. The reason for this is discussed and a synthesis of both methods is proposed.

Seroprevalence and risk factors of Toxoplasma gondii infection among pregnant women in south western, Saudi Arabia

This study aimed to determine the seroprevalence of Toxoplasma gondii in pregnant women in the south western region of Saudi Arabia and to find out the possible risk factors that may lead to infection. This cross sectional hospital based study was carried out at three hospitals in the south western region of Saudi Arabia from January 2008 to August 2010. Blood samples from 487 pregnant women were collected and used to detect anti-T. gondii antibodies IgM and IgG by enzyme linked immunosorbent assay (ELISA). A questionnaire interview was carried out to ask about some risk factors of infection. Among the 487 studied pregnant women, 38.8 % were seropositive for anti T. gondii IgG while 6.2 % were positive for anti T. gondii IgM and 3.3 % were positive for both anti T. gondii IgG & IgM. The only risk factor associated with seropositive anti T. gondii IgM was the history of the intake of immunosuppressive drugs. Regarding anti T. gondii IgG seropositivity, it was found to increase significantly with increased age, number of gravida and parities, and previous history of toxoplasmosis. The seroprevalence of T. gondii IgG & IgM by ELISA among pregnant women in the south western region of Saudi Arabia is considerable with few identifiable significant risk factors reported.

Seasonal variations in acute toxoplasmosis in pregnant women in the Rhône-Alpes region (France)

To search for seasonal variations we analysed data on 1998 acute toxoplasmic infections diagnosed between 1988 and 2009 in pregnant women. Two distinctive transmission profiles were observed: one in rural areas, which was strongly influenced by seasons with significantly fewer infections in the first half of the year but maximal risks at the end of summer and end of autumn, and a stable urban distribution with only moderate peaks. Further studies on individual risks and environmental and climatic factors are needed to understand what prevention message should be given to susceptible pregnant women.