Toxocara seroprevalence in schizophrenic patients in Turkey

Association between Toxocara Spp. Exposure and Schizophrenia: A Case-Control Study

Background

Toxocariasis is a zoonotic disease caused by the larvae of Toxocara canis or Toxocara cati. Patients with schizophrenia may be at higher risk of infection, possibly due to their cognitive and personal self-care impairments. We aimed to assess the association between Toxocara spp. exposure and schizophrenia.

Methods

This case-control study was conducted on 109 patients with schizophrenia admitted to Ibn Sina Hospital, Shiraz, Iran, and 104 age- and gender-matched healthy controls from May to September 2021. A questionnaire was obtained and serum samples were tested for IgG antibodies to Toxocara excretory/secretory (TES) antigens using an enzyme-linked immunosorbent assay (ELISA).

Results

Anti-Toxocara IgG was detected in 12 schizophrenic patients and 10 control subjects, giving respective seroprevalences of 11.0% (95% confidence interval [95% CI]=5.8-18.4%) and 9.6% (95% CI=4.7-17.0%). Univariate logistic analyses estimated an odds ratio (OR) of 1.16 (95% CI=0.44-3.16); however, it was not statistically significant (P=0.915). Individuals with a history of eating unwashed vegetables or fruits (23.1%, 95% CI=9.0-43.6, crude odds ratio [COR]=3.21, 95% CI=1.13-9.13) and rural residency (19.5%, 95% CI=8.8-34.9, COR=2.74, 95% CI=1.06-7.05) had significantly higher rates of seropositivity using the univariate logistic analyses. After multivariate logistic analyses, the differences were not statistically significant.

Conclusion

The toxocariasis seroprevalence among schizophrenic and healthy participants was not significantly different (11% vs. 9.6%). Since the disease severity, onset, and cognitive sequelae are not the same among schizophrenic patients, clinically matched studies with larger samples are required to address the current inconsistency between the studies.

Gastrointestinal helminths of stray dogs in Erzurum province: prevalence and risk to public health

Dogs have an important role in public health due to their close contact with humans and living in common areas. This study was aimed to investigate the presence and prevalence of gastrointestinal system helminths in stray dogs in Erzurum province. Gastrointestinal helminth eggs were detected in a total of 190 out of 446 (42.6%) in stray dogs in Erzurum province. In the study, taeniid eggs (17.71%, 79/446), T. canis (16.82%, 75/446), T. leonina (12.78%, 57/446), Linguatula spp. (4.48%, 20/446), spiny-headed worms (2.91%, 13/446), hookworms (2.69%, 12/446), Alaria spp. (1.12%, 5/446) and Trichuris spp. (0.22%, 1/446) eggs were observed. In addition, proglottid structures of Mesocestoides spp. (3.14%), Taenia spp. (2.69%), and D. caninum (1.12%), adults of Alaria spp. (0.22%), T. canis (0.22%), and T. leonina (0.22%) were detected. According to the results of the study, zoonotic parasites including taeniid cestodes, T. canis, Linguatula spp., spiny-headed worm, hookworm, Alaria spp., and Trichuris spp. were common in stray dogs in the province. Public health risks can be reduced by regular deworming of dogs, proper management of the process, prevention of environmental contamination with dog feces, and proper enforcement of sanitation protocols.

Galectins - Important players of the immune response to CNS parasitic infection

Galectins are a family of proteins that bind β-galactosides and play key roles in a variety of cellular processes including host defense and entry of parasites into the host cells. They have been well studied in hosts but less so in parasites. As both host and parasite galectins are highly upregulated proteins following infection, galectins are an area of increasing interest and their role in immune modulation has only recently become clear. Correlation of CNS parasitic diseases with mental disorders as a result of direct or indirect interaction has been observed. Therefore, galectins produced by the parasite should be taken into consideration as potential therapeutic agents.

Human Toxocariasis in individuals with blood disorders and cancer patients: the first seroepidemiological study in Iran

Toxocara is one of the most prevalent nematodes in Iran, which infect humans as an intermediate host. Infection complications result from the larva migration. Human toxocariasis prevalence was various in Iran according to the area of study and population. This study was designed to evaluate the seropositivity of Toxocara IgG in patients with blood disorders and cancer patients in southwest Iran. Moreover, the study of the associated risk factors for this infection. A total of 1122 serum samples, from February 8, 2019 to August 21, 2019, including 600 healthy individuals and 522 individuals with cancer and blood disorders patients were collected. Serum samples were collected for detection of Toxocara IgG by using ELISA (Enzyme-Linked Immunosorbent Assay) kit. Sociodemographic data of all participants were collected and examined to determine their association with the infection. Out of 101 individuals with white blood cell disorders (5.94%), red blood cell disorders (7.48%) and cancer patients (11.06%) were seropositive for Toxocara IgG antibodies. The infection rate among all study population revealed that (10.76%) were positive for Toxocara IgG. This study showed the fundamental role of contact with pets and infection in groups with blood cell disorders (P-value ≤ 0.05%); while in cancer patients the association wasn't significant. Other factors such as age, location of residence, and sex showed that the association with this infection wasn't significant.

Toxocara infection/exposure and the risk of schizophrenia: a systematic review and meta-analysis

Toxocariasis is an important neglected disease that could have a role in the development of some neurological disorders, such as schizophrenia (SCZ). We performed the first systematic review and meta-analysis on observational studies to evaluate the possible association between Toxocara infection/exposure and SCZ. Systematic searching (PubMed, Scopus, Web of Science and Google Scholar) was performed, up to 15 August 2020, to identify the relevant studies. We used a random effects meta-analysis model to generate the pooled OR and 95% CIs. The research process resulted in the identification of six studies related to the subject of interest entailing 411 SCZ patients and 2047 controls. Our results demonstrated that the SCZ patients (15%; 95% CI 6.8 to 29.9%) had higher pooled seroprevalence of Toxocara infection/exposure than the control group (3.3%; 95% CI 1.1 to 9.4%), showing a significant association (pooled OR, 4.06; 95% CI 1.14 to 14.43). Our findings suggested that Toxocara infection/exposure might have an important but neglected contribution to SCZ development. However, further well-designed and large-scale observational studies are needed to illuminate this association. Because many other environmental and genetic factors may be strong confounders, more mechanistic/experimental studies in animal models are also necessary to further define the mechanism of this association.

Seroprevalence, risk factors, and clinical symptoms of Toxocara spp. infection among children 3-15 years old in northern Iran

The World Health Organization has categorized toxocarosis as a neglected tropical disease despite its significant impact on high-risk groups such as children. This study aimed to investigate the seroprevalence, risk factors, and clinical symptoms of Toxocara spp. infection among children 3-15 years old in northern Iran. A total of 386 children were enrolled in the study. All serum samples were tested for the presence of IgG antibodies against Toxocara spp. infection using an enzyme-linked immunosorbent assay. Moreover, relevant risk factors and clinical symptom data were obtained using questionnaires. Data analysis was performed using the SPSS software version 24. The overall seroprevalence of Toxocara spp. infection was found 2.85 % (11/386). However, Toxocara spp. infection was high for some risk factors, including eating soil (14.3 %), contacting cats (6.7 %), and consuming raw vegetables (3.7 %). However, there were no statistically significant differences regarding the risk factors and socio-demographic characteristics. Considering the clinical symptoms, Toxocara spp. infection was different in children with eosinophilia (20 %), ocular disorders (8.3 %), skin disorders (7.7 %), liver disorders (4.5 %), and stomach ache (4.2 %), although not statistically significant. The results revealed that the seroprevalence of Toxocara spp. infection was relatively low in children in northern Iran. It is suggested to conduct more studies in different parts of Iran to gain a deeper understanding of the toxocarosis seroprevalence and its status in high-risk groups such as children with asthma, hypereosinophilic syndrome, allergic skin disorders, and epilepsy.

Neurocognitive and neuropsychiatric effects of toxocariasis

Caused by the neuroinvasive nematodes Toxocara canis and Toxocara cati, human toxocariasis has a worldwide distribution with seroprevalence in humans associated with low socioeconomic status and low educational attainment. Third-stage Toxocara larvae can invade human tissues, including the brain and spine, where they can result in encephalitis, meningitis, and inflammation. Toxocara infection in animal models has been associated with cognitive and behavioural changes. In humans, preliminary cross-sectional research suggests that Toxocara seropositivity is associated with worse cognitive function in children and adults. Additional preliminary cross-sectional findings suggest associations between Toxocara seropositivity and neuropsychiatric function, including schizophrenia and neurologic conditions such as epilepsy. Given the widespread distribution of human toxocariasis and early evidence suggesting that it can be associated with cognitive and neuropsychiatric function in humans, additional research regarding the effects of toxocariasis on the human brain is required.

Sources and seroprevalence of toxocariasis in Turkey

Toxocariasis in humans is considered a rare disease in Turkey, and the absence of specific symptoms of this disease is probably the main reason for clinicians to underestimate and underdiagnose the disease. Although there are several seroepidemiological studies on visceral larva migrans in the country, a comparison between them is difficult as the serological tests are not standardised. After the introduction of the easily accessible ELISA kit in the market, the number of seroepidemiological studies has increased in which the reported rates ranged between 1% and 56%. Similar to other countries, Toxocara seropositivity in Turkey is more common in men, childhood, in those living in rural area, having a low income level, owning dogs, and biting their nails or practicing geophagia. In addition, toxocariasis is a risk factor for veterinarians, farmers, and pet-shop workers. Toxocara seroprevalence is significantly higher in respiratory, neuropsychiatric, musculoskeletal, skin and abdominal disorders. There are also many studies showing the importance of eosinophilia in toxocariasis. In conclusion, although there are many studies on toxocariasis in Turkey, it is still not well understood to what extent the infection is responsible for a plethora ascribed symptoms. Standardisation of the diagnostic methods and the use of molecular techniques could further throw light in the real epidemiology and the role played by the infection to induce signs and symptoms.

Seroprevalence of Toxocara canis infection and associated risk factors among primary schoolchildren in rural Southern Thailand

BACKGROUND

Human toxocariasis is a parasitic zoonosis caused by a parasite in the genus Toxocara and is transmitted mainly by the accidental ingestion of embryonated Toxocara canis (dog roundworm) or T. cati (cat roundworm) eggs. Several studies reported that children were the main population at risk for T. canis infection. Currently, no reports on the seroprevalence of T. canis infection in Thailand are available, and its status remains unknown among children who live in rural areas of southern Thailand.

OBJECTIVE

This study aimed to investigate the seroprevalence of T. canis infection and its associated risk factors among primary schoolchildren in rural areas of Nakhon Si Thammarat Province, Thailand.

METHODS

A total of 177 schoolchildren between 6 and 13 years of age were recruited between June and July 2019. Serum anti-T. canis IgG antibodies were detected with a commercial ELISA kit. A questionnaire administered by direct interviews was used to collect demographic and behavioral risk factor data.

RESULTS

The overall seroprevalence of T. canis infection was 58.2% (103 of 177). The univariate analysis revealed that schoolchildren who did not practice handwashing before a meal (crude odds ratio (COR) = 3.67, 95% CI 1.93-6.95, P < 0.001), did not practice hand washing after animal contact (COR = 2.89, 95% CI 1.53-5.47, P = 0.001), and drank untreated water (COR = 1.87, 95% CI 1.00-3.48, P = 0.049) had an increased risk of acquiring T. canis infection. However, after adjusting for confounders, only a lack of handwashing before a meal remained a significant risk factor (adjusted odds ratio (AOR) = 2.20, 95% CI 1.11-4.34, P = 0.023). Age, sex, owning a dog, and eating fresh vegetables were not significantly associated with T. canis infection in the current study.

CONCLUSIONS

This is the first serological investigation of T. canis infection among schoolchildren in Thailand. The high rate of Toxocara seropositivity reflected high levels of exposure to T. canis among schoolchildren in rural areas of southern Thailand. The results also provide baseline data regarding modifiable risk behaviors for effective T. canis infection prevention strategies in southern Thailand, especially strengthening hand washing practices among schoolchildren.

Toxocara: Protecting pets and improving the lives of people

Toxocara sp. are zoonotic parasitic roundworms that cause infection and morbidity in both developed and developing countries. In humans, infection is thought to be most common in children, particularly those living in poverty, and usually results from consumption of soil contaminated with parasite eggs deposited by dog or cat faeces. Infection in humans results in different clinical manifestations, some more overt like visceral or ocular larva migrans and others more cryptic like neurocognitive delay. Despite its pervasiveness, toxocariasis has become a neglected infection. We review the dynamics of the human-animal interface in the context of this parasite, discuss the challenges in controlling transmission to humans, and cite key areas of research that could enable improved interventions. With political will and proper resource allocation, we propose that effective interventions are possible in the near term.

Toxocara-induced neural larva migrans (neurotoxocarosis) in rodent model hosts

Neural larva migrans (NLM), or neurotoxocarosis, induced by Toxocara canis or Toxocara cati results from migrating and persisting larvae in the central nervous system of paratenic hosts, including humans. As the diagnosis of NLM in humans is not straightforward, most knowledge on the disease is derived from only a few published clinical cases. To improve our understanding of human NLM, studies on the pathogenesis and clinical symptoms in laboratory animal model systems are indispensable, and rodents have been accepted as the most appropriate model organisms for NLM. As research has mostly focused on neuroinvasive T. canis-larvae, information regarding the pathogenesis of T. cati-induced NLM remains scarce. This review summarises the current state of knowledge on neuroinvasion by both T. canis and T. cati in different rodent model hosts, the resulting behavioural changes, and histopathological alterations during the course of NLM as well as the potential molecular pathogenic mechanisms.

Pathogenesis of cerebral toxocariasis and neurodegenerative diseases

Toxocara canis belongs to one of zoonotic parasites that commonly infects canines worldwide, and its eggs in host faeces may contaminate the food, water, soil and their fur as well as the larvae entrapped in the granuloma can infect paratenic hosts including mice and humans. Survivability of T. canis embryonated eggs under moist, cool conditions may be as long as 2-4 years or more. In paratenic hosts such as mice and humans, T. canis L3 larvae neither moult, grow, nor replicate and will wander through a number of internal organs in humans so as to cause Th2-dominant pathology in various internal organs as leading to neurotoxocariasis (NT), ocular toxocariasis (OT), or visceral larva migrans (VLM). Although the systemic immune response to T. canis has been widely reported, the immune response in the brain has received little attention. Differential cytokine expression and other brain injury-associated biomarkers or neurodegeneration-associated factors have been observed in infected versus uninfected outbred and inbred mice. Preliminary data have also suggested a possible link between significant memory impairment and cytokine production associated with T. canis infection in the hippocampus which has been long recognised as being responsible for learning and memory functions. Notably, it remains an enigma concerning cerebral invasion by T. canis larvae rarely induces a recognisable neurological syndrome or its involvement in neuropathological disorders in humans. Exploration of the relationship between host and parasite in the brain may elucidate the cryptic symptoms of human cerebral toxocariasis, with patients presenting with mental retardation, epilepsy, neurodegeneration and other central nervous system (CNS) disorders.

Associations of mental disorders and neurotropic parasitic diseases: a meta-analysis in developing and emerging countries

BACKGROUND

Although they are declining worldwide, neurotropic parasitic diseases are still common in developing and emerging countries. The aim of this study was to estimate the pooled prevalence and pooled association measures of comorbidities between mental disorders (anxiety, depression, bipolar disorder, and schizophrenia) and neurotropic parasitic diseases (malaria, cysticercosis, toxoplasmosis, human African trypanosomiasis, Chagas disease, and human toxocariasis) in developing and emerging countries.

METHODS

As the first meta-analysis on this topic, this study was performed in accordance with PRISMA guidelines. The protocol was registered in PROSPERO (N°CRD42017056521). The Medline, Embase, Lilacs, and Institute of Epidemiology and Tropical Neurology databases were used to search for articles without any restriction in language or date. We evaluated the quality of studies independently by two investigators using the Downs and Black assessment grid and pooled estimates using the random-effects method from CMA (Comprehensive Meta Analysis) Version 3.0.

RESULTS

In total, 18 studies published between 1997 and 2016 met our inclusion criteria. We found that the prevalence of anxiety and depression in people suffering from Chagas disease and/or neurocysticercosis was 44.9% (95% CI, 34.4-55.9). In 16 pooled studies that included 1782 people with mental disorders and 1776 controls, toxoplasmosis and/or toxocariasis were associated with increased risk of schizophrenia and/or bipolar disorders (odds ratio = 2.3; 95% CI, 1.7-3.2). Finally, toxocariasis and/or toxoplasmosis were associated with an increased risk of the onset of schizophrenia (odds ratio = 2.4; 95% CI, 1.7-3.4).

CONCLUSION

Our pooled estimates show that the associations between diseases studied are relatively high in developing and emerging countries. This meta-analysis supports the hypothesis that toxoplasmosis could be the cause of schizophrenia. These findings could prove useful to researchers who want to further explore and understand the associations studied.

Visceral larva migrans detection using PCR-RFLP in BALB/c mice infected with Toxocara canis

Toxocara canis is an important zoonotic roundworm distributed worldwide. The infective larvae of T. canis are one of the causes of visceral larva migrans (VLM), a clinical syndrome in humans. Diagnosing VLM is difficult, and the differential diagnosis of the larval development stage is limited. Therefore, this experimental research aimed to diagnose T. canis larvae using a molecular method, not only in liver tissue, which is the most commonly affected tissue, but also in the limb muscles, lungs and brain tissues. For this purpose, 24 BALB/c mice were infected with 1000 embryonated T. canis eggs. Necropsies were performed on the second, fourth, seventh and 14th days post-infection. While a part of the samples were digested with pepsin-HCl, the molecular method was used for the remainder of the samples to replicate the mitochondrial DNA adenosine triphosphate (ATP) synthase subunit-6 gene region of T. canis. BbsI, a restriction endonuclease, was used to determine the specificity of the amplicons obtained from Polymerase chain reaction (PCR). The detection limit for embryonated eggs was recorded. The PCR results showed that the sensitivity of the PCR analysis was 83.3% in the liver (with 88.8% accuracy), 87.5% in the lungs (with 91.6% accuracy) and 75.0% in the brain, forelimb and hindlimb muscles (with 83.3% accuracy). In all tissues, the test specificity was determined to be 100%. In this study, the molecular method was applied to only experimentally infected BALB/c mice tissues; thus, it is suggested that it can be also employed in different paratenic hosts and materials possibly infected with T. canis.

Toxocariasis in humans in Africa - A systematic review

BACKGROUND

Toxocariasis is a globally distributed zoonosis. The most important definitive hosts are dogs, whereas humans serve as paratenic hosts. Transmission to humans occurs by accidental ingestion of eggs, e.g. by consumption of contaminated fruits or vegetables. Although exposure to Toxocara is usually considered as relatively benign, it is implicated in a range of neurological, ophthalmologic and other organ-specific conditions, some of them with grave consequences. This review provides an overview on the epidemiology, presentation and risk factors of exposure to Toxocara in Africa.

METHODS

A systematic search was performed for studies published after January 1st, 1990, in English, French, Portuguese, Spanish, Dutch or German. The review was prepared according to PRISMA guidelines. Studies on toxocariasis in human populations and contamination in human environments were included.

RESULTS

Sixty-five papers were included. Antibodies against Toxocara spp. in humans were found to be very common across Africa. Severe manifestations have been reported mainly from North Africa. Environmental contamination including soil, vegetables and fruits sold on markets was demonstrated in various locations in Africa.

CONCLUSIONS

Exposure to Toxocara is prevalent across the African continent. However, the complication frequency, the impact of the condition on the individual and the public health relevance of this zoonosis, and the economic impact have never been systematically evaluated.

Cerebral Toxocariasis: Silent Progression to Neurodegenerative Disorders?

Toxocara canis and T. cati are highly prevalent nematode infections of the intestines of dogs and cats. In paratenic hosts, larvae do not mature in the intestine but instead migrate through the somatic tissues and organs of the body. The presence of these migrating larvae can contribute to pathology. Toxocara larvae can invade the brains of humans, and while case descriptions of cerebral toxocariasis are historically rare, improved diagnosis and greater awareness have contributed to increased detection. Despite this, cerebral or neurological toxocariasis (NT) remains a poorly understood phenomenon. Furthermore, our understanding of cognitive deficits due to toxocariasis in human populations remains particularly deficient. Recent data describe an enhanced expression of biomarkers associated with brain injury, such as GFAP, AβPP, transforming growth factor β1 (TGF-β1), NF-L, S100B, tTG, and p-tau, in mice receiving even low doses of Toxocara ova. Finally, this review outlines a hypothesis to explore the relationship between the presence of T. canis larvae in the brain and the progression of Alzheimer's disease (AD) due to enhanced AD-associated neurodegenerative biomarker expression.

Seroprevalence, disease awareness, and risk factors for Toxocara canis infection among primary schoolchildren in Makoko, an urban slum community in Nigeria

In this study, we investigated the seroprevalence of Toxocara canis infection in southern Nigeria, which previously was unknown, in addition to evaluating disease awareness and potential risk factors for schoolchildren in an urban slum community. In total, 366 primary schoolchildren were investigated for the presence of anti-Toxocara IgG antibodies. Blood was collected and screened by a Western blot analysis based on the excretory-secretory antigens of larval T. canis (TcES), targeting low molecular weight bands of 24-35kDa specific for T. canis. Children were considered seropositive if their serum reacted with TcES when diluted to a titer of 1:32. Questionnaires concerning possible risk factors were given to the schoolchildren to acquire data on this infection. The overall seroprevalence of Toxocara infection was 86.1% (315/366). The logistic regression analysis of risk factors showed that children's age (odds ratio (OR)=2.88, 95% confidence interval (CI)=1.08-7.66, p=0.03), contact with dogs (OR=0.51, 95% CI=0.28-0.94, p=0.03), the age of the dog (OR=0.34, 95% CI=0.18-0.68, p=0.002), the feeding location of the dog (OR=0.31, 95% CI=0.12-0.79, p=0.01), the consumption of raw vegetables (OR=0.89, 95% CI=0.54-1.48, p=0.004), and the drinking of unboiled water (OR=0.48, 95% CI=0.26-0.90, p=0.02) were risk factors associated with Toxocara infection. Although there was a high awareness of dogs being hosts of some parasites in this study, not much was known about T. canis. This is the first serological investigation of T. canis infection among primary schoolchildren in southern Nigeria. The high seroprevalence recorded is an indication of high transmission with the consequent risk of visceral or ocular larval migrans and neurologic toxocariasis in these children. Our findings suggest the need for prompt interventional measures, particularly health education on personal hygiene.

Sero-Epidemiology of Toxocara Canis Infection in Children Attending Four Selected Health Facilities in the Central Region of Ghana

OBJECTIVE

The study determined the seroprevalence of Toxocara canis infection among children attending four selected health facilities in the Central Region of Ghana.

DESIGN

Cross-sectional study.

METHOD

Sera from 566 children aged 1-15 years attending four selected health facilities in the Central Region of Ghana between July and September 2012 was used in a Toxocara excretory-secretory antigen-based ELISA to detect serum IgG. A short questionnaire was designed to obtain data on respondents as to age, gender, educational level, locality of residence, habits of washing of fruits, vegetable and hands before eating, keeping of pet (dogs or cats), and history of playing with soil and pets. Clinical information was also collected. Associations between sero-positivity and age group, gender, risk factors, educational level and other variables were determined by Chi square test.

RESULTS

The overall sero-prevalence was 53.5% (n=566). Age, educational level and hospital visited were significantly associated with sero-positivity (p< 0.05). Children with history of playing with soil (χ(2)=9.03, p=0.003), pet-keeping (χ(2)=14.77, p=0.001) and not washing hands with soap before eating (χ(2)=5.82, p=0.016) were significantly associated with sero-positivity.

CONCLUSION

The sero-prevalence of T. canis infection in children in the study was high. The children should be educated to desist from risk factors such as playing with soil and pets and be encouraged to ensure proper personal hygiene.

Microarray gene expression analysis reveals major differences between Toxocara canis and Toxocara cati neurotoxocarosis and involvement of T. canis in lipid biosynthetic processes

Toxocara canis and Toxocara cati are globally occurring intestinal nematodes of dogs and cats with a high zoonotic potential. Migrating larvae in the CNS of paratenic hosts, including humans, may cause neurotoxocarosis resulting in a variety of neurological symptoms. Toxocara canis exhibits a stronger affinity to the CNS than T. cati, causing more severe neurological symptoms in the mouse model. Pathomechanisms of neurotoxocarosis as well as host responses towards the respective parasite are mostly unknown. Therefore, the aim of this study was to characterise the pathogenesis at a transcriptional level using whole genome microarray expression analysis and identify differences and similarities between T. canis- and T. cati-infected brains. Microarray analysis was conducted in cerebra and cerebella of infected C57Bl/6J mice 42daysp.i. revealing more differentially transcribed genes for T. canis- than T. cati-infected brains. In cerebra and cerebella of T. canis-infected mice, a total of 2304 and 1954 differentially transcribed genes, respectively, were identified whereas 113 and 760 differentially transcribed genes were determined in cerebra and cerebella of T. cati-infected mice. Functional annotation analysis revealed major differences in host responses in terms of significantly enriched biological modules. Up-regulated genes were mainly associated with the terms "immune and defence response", "sensory perception" as well as "behaviour/taxis" retrieved from the Gene Ontology database. These observations indicate a strong immune response in both infection groups with T. cati-infected brains revealing less severe reactions. Down-regulated genes in T. canis-infected cerebra and cerebella revealed a significant enrichment for the Gene Ontology term "lipid/cholesterol biosynthetic process". Cholesterol is a highly abundant and important component in the brain, representing several functions. Disturbances of synthesis as well as concentration changes may lead to dysfunction in signal transduction and neurodegenerative disease. Overall, only a minor overlap of differentially transcribed genes was observed between the two infection groups in both brain parts. Most genes are regulated individually in each infection group, supporting the evident differences of both roundworm species observed in the paratenic host in previous studies. In summary the present study underlines the differences in pathogenicity of T. canis and T. cati. It furthermore provides a comprehensive basis for future analyses over the course of infection as well as functional tests to identify gene regulatory circuits that are crucial for pathogenesis of neurotoxocarosis. The results of this study provide a promising foundation for further specific research to evaluate the particular pathogenetic mechanisms and to identify possible therapeutic targets.

Seroepidemiological Study of Toxocariasis among Volunteers Animal Husbandry Workers and Veterinary in Southern Anatolia in Turkey in 2014

BACKGROUND

Human toxocariasis is a parasitic infection caused by the larvae of Toxocara canis. We examine the Toxocara seroprevalance in veterinarians and animal husbandry workers living in the Mugla Province, Turkey to evaluate better the risk factors for Toxocara exposure.

METHODS

In 2014, 376 volunteers participated in the study in 2014. All blood specimens were tested using a commercial enzyme immunoassay kit and ELISA positive samples were confirmed by Western Blot (WB) method.

RESULTS

The seroprevalence of Toxocara, as determined by WB, was 8%. A statistically significant correlation was evident between patient age and Toxocara positivity among animal husbandry workers (P = 0.029). A strong association was also evident between sex and seropositivity in the animal husbandry group (P=0.024). Veterinarians working in pet clinics did in fact exhibit higher Toxocara seropositivities relative to those of other groups (P = 0.029). A statistically significant difference was detected between the rural geographic areas surveyed (P = 0.04).

CONCLUSION

In Mugla Province, seroprevalence of Toxocara is lower than other regions. Despite the low seroprevalence observed, especially in high risk professions toxocariasis remains an important medical concern within the region.

Low seroprevalence of Toxocara infection in schizophrenic inpatients in durango, Mexico: a case control study

Psychiatric patients have a higher seroprevalence of toxocariasis than general population. However, there is poor knowledge about any specific psychiatric diagnosis associated with toxocariasis. The aim of the study was to determine whether seropositivity to Toxocara was associated with schizophrenia. Through an age and gender-matched case-control seroprevalence study in Durango City, Mexico, 50 schizophrenic inpatients in a public psychiatric hospital and 100 control subjects of the general population were compared for the presence of anti-Toxocara IgG antibodies. One of the 50 (2%) schizophrenic inpatients, and 3 (3%) of the 100 controls were positive for anti-Toxocara IgG antibodies. No statistically significant difference in Toxocara seroprevalence among cases and controls was found (P=0.59). The Toxocara positive schizophrenic patient suffered from paranoid schizophrenia (F20.0) and had a number of putative risk factors for Toxocara exposure including contact with cats, dogs and other animals, worked in agriculture, and consumed undercooked meat, unwashed fruits and vegetables, and untreated water. Results suggest that seroprevalence of Toxocara infection was low and not associated with schizophrenia in psychiatric inpatients in Durango, Mexico. However, further studies to elucidate the association of toxocariasis with schizophrenia are needed.

Toxocara seroprevalence among clinically healthy individuals, pregnant women and psychiatric patients and associated risk factors in Shandong Province, Eastern China

BACKGROUND

Toxocarosis is a widespread zoonosis caused by the ascarid nematodes Toxocara canis and Toxocara cati, which primarily infect dogs and cats, respectively. Most human infections with Toxocara are asymptomatic; however, some infected individuals may develop a serious illness and even death. Nevertheless, epidemiological knowledge regarding the prevalence and risks associated with Toxocara infection is limited in China. Therefore, we performed a cross-sectional pilot study and estimated the seroprevalence of Toxocara infection in humans in Shandong Province, eastern China for the first time, from June 2011 to July 2013, involving clinically healthy individuals, pregnant women and psychiatric patients, aiming to attract public attention to Toxocara infection.

METHODOLOGY/PRINCIPLE FINDINGS

Seroprevalence of Toxocara was determined using an enzyme-linked immunosorbent assay based on a cross-sectional study conducted in Qingdao and Weihai, Shandong Province, eastern China. Factors potentially associated with Toxocara infection were identified by logistic regression analysis. The overall Toxocara seroprevalence among the study population (n = 2866) was 12.25%, and a significantly higher seroprevalence in psychiatric patients (16.40%, 73/445) than that in clinically healthy individuals (13.07%, 187/1431) and pregnant women (9.19%, 91/990) was revealed. Univariate analyses suggested that keeping dogs at home (OR = 0.06, 95% CI 0.05-0.08, P<0.001), contact with cats and dogs (OR = 0.42, 95% CI 0.33-0.53, P<0.001) and exposure with soil (OR = 0.37, 95% CI 0.28-0.49, P<0.001) were risk factors associated with Toxocara infection.

CONCLUSIONS/SIGNIFICANCE

The present study revealed, for the first time, that human infection with Toxocara is common in eastern China, posing a significant public health concern. Increasing human and dog populations, population movements and climate change all will serve to increase the importance of this zoonosis. Further studies under controlled conditions are necessary to define potential morbidity associated with Toxocara infection.

Investigation of anti-Toxocara and anti-toxoplasma antibodies in patients with schizophrenia disorder

Objective. The aim of the present study was to examine the relationship between Toxoplasma gondii and Toxocara spp. infections in patients with schizophrenia disorder. Method. A total of 100 patients with schizophrenia disorder and 95 healthy individuals participated in the study. Participants were tested for the presence of anti-T. gondii and anti-Toxocara spp. antibodies by ELISA and Western blotting. Data were analyzed using Chi-square test and Fisher 9 s exact test. Results. There were no differences in T. gondii IgG seroprevalence between patients with schizophrenia and healthy individuals (P = 0.1), but there were differences in seroprevalence between males and females with schizophrenia (P = 0.009). In contrast, Toxocara spp. IgG seroprevalence was greater in patients with schizophrenia disorder than in healthy individuals (P = 0.02), but there were no differences in seroprevalence between men and women with schizophrenia (P = 0.5). Finally, there were no differences in seroprevalence of T. gondii or Toxocara spp. IgG among different subtypes of schizophrenia, various age groups, residential area, or clinical course of treatment (P > 0.05). Conclusion. The present study suggests that patients with schizophrenia disorder are at elevated risk of Toxocara spp. infection. Moreover, contamination with T. gondii is a risk factor for schizophrenia in women.

Toxocara infection in psychiatric inpatients: a case control seroprevalence study

BACKGROUND

There is poor knowledge about the epidemiology of toxocariasis in psychiatric patients.

AIMS

Determine the seroepidemiology of Toxocara infection in psychiatric patients.

METHODS

Through a case-control seroprevalence study, 128 psychiatric inpatients and 276 control subjects were compared for the presence of anti-Toxocara IgG antibodies in Durango, Mexico. Socio-demographic, clinical, and behavioral characteristics of inpatients associated with toxocariasis were also investigated.

RESULTS

Six of the 128 (4.7%) psychiatric inpatients, and 3 (1.1%) of the 276 controls were positive for anti-Toxocara IgG antibodies (P = 0.03). Stratification by age showed that Toxocara seroprevalence was significantly (P = 0.02) higher in patients aged ≤50 years old (6/90∶6.7%) than controls of the same age (2/163∶1.2%). While Toxocara seroprevalence was similar in patients and controls aged >50 years old. Stratification by gender showed that Toxocara seroprevalence was significantly (P = 0.03) higher in female patients (2/37∶5.4%) than in female controls (0/166∶0%). No statistically significant associations between Toxocara seropositivity and clinical characteristics were found. In contrast, Toxocara seropositivity was associated with consumption of goat meat and raw sea snail.

CONCLUSIONS

This is the first report of toxocariasis in psychiatric inpatients in Mexico. Further studies with larger sample sizes are needed to elucidate the association of toxocariasis with psychiatric diseases. The role of the consumption of goat meat and raw sea snail in the transmission of Toxocara deserve further investigation.

Investigation of anti-Toxocara antibodies in epileptic patients and comparison of two methods: ELISA and Western blotting

The relationship between Toxocara infection and epilepsy was previously demonstrated by several case-control studies and case reports. These previous studies were often based on the enzyme-linked immunosorbent assay (ELISA) using Toxocara excretory-secretory antigens, which are not specific due to cross-reactivity with other parasitic infections such as ascariasis, trichuriasis, and anisakiasis. An immunoblot analysis is highly specific and can detect low levels of Toxocara antibodies. Therefore, this assay may be useful in the identification of toxocariasis in epileptic patients. We examined patients who had epilepsy and healthy subjects for seropositivity for Toxocara infection by ELISA and Western blotting. Out of 85 epileptic patients, 10 (11.8%) and 3 (3.5%) persons exhibited Toxocara immunoglobulin G (IgG) antibodies responses by ELISA and by both techniques, respectively. Moreover, in the healthy group (n = 85), 3 (3.5%) persons were positive by ELISA, but none was detected by Western blotting. This study indicates that Toxocara infection is a risk factor for epilepsy in Iran. These findings strongly suggest the need to perform Western blotting immunodiagnosis, as well as the ELISA using Toxocara excretory-secretory antigens, to improve diagnosis of human toxocariasis in patients with epilepsy.

Infectious agents associated with schizophrenia: a meta-analysis

Schizophrenia is a highly disabling and limiting disorder for patients and the possibility that infections by some microorganisms may be associated to its development may allow prevention and recovery. In the current study we have done a meta-analysis of studies that have assessed the possible association between detection of different infectious agents and schizophrenia. We report results that support the idea that there is a statistically significant association between schizophrenia and infection by Human Herpesvirus 2 (OR=1.34; CI 95%: 1.09-1.70; p=0.05), Borna Disease Virus (OR=2.03; CI 95%: 1.35-3.06; p<0.01), Human Endogenous Retrovirus W (OR=19.31; CI 95%: 6.74-55.29; p<0.001), Chlamydophila pneumoniae (OR=6.34; CI 95%: 2.83-14.19; p<0.001), Chlamydophila psittaci (OR=29.05; CI 95%: 8.91-94.70; p<0.001) and Toxoplasma gondii (OR=2.70; CI 95%: 1.34-4.42; p=0.005). The implications of these findings are discussed and further research options are also explicated.

Expression and evaluation of Chikungunya virus E1 and E2 envelope proteins for serodiagnosis of Chikungunya virus infection

PURPOSE

Chikungunya virus (CHIKV) causes endemic or epidemic outbreaks of CHIKV fever, which is a mosquitoe- transmitted viral disease in Africa, India, South-East Asia, and recently Southern Europe. Currently, serological diagnostic tests such as hemagglutination inhibition test (HI test), in-house IgM capture enzyme-linked immunosorbent assays (ELISA), and indirect immunofluorescence test were used for diagnosis of chikungunya fever, which are based on whole virus antigens.

MATERIALS AND METHODS

CHIKV E1, and E2 envelope proteins for the CHIKV-specific serodiagnostic reagents for chikungunya fever were expressed in baculovirus expression system. The seroreactivity of recombinant CHIKV E1 and E2 envelope proteins were evaluated using sera panels of patients from Laboratoire Marcel Merieux by indirect IgM capture ELISA.

RESULTS

The recombinant CHIKV E1 and E2 envelope protein showed sensitivity of 77.5% and 90%, respectively. The specificities of both CHIKV E1 and E2 envelope proteins were 100%.

CONCLUSION

The recombinant CHIKV E1 and E2 envelope proteins could be a useful diagnostic reagent for CHIKV infection.