Parasitic central nervous system infections in immunocompromised hosts

Spinal schistosomiasis mimickingspinal tumour: a case report

Introduction and importance

Schistosomiasis, a parasitic disease, is caused by blood flukes from the schistosoma genus. Neuroschistosomiasis is the most severe form of schistosomiasis, which occurs when the host's brain and spinal cord react to the deposition of eggs, leading to neurological symptoms. Neuroschistosomiasis causes various signs and symptoms, such as myelopathy, radiculopathy, and elevated intracranial pressure.

Case presentation

A 12-year-old child from Ethiopia who presented with progressive weakness in his lower extremities that has been ongoing for 2 months. Alongside the weakness, the patient also experienced tingling sensations and numbness in his lower extremities. Additionally, he had bladder and bowel incontinence. Spinal MRI showed signs suggestive of myxopapillary ependymoma, but the histopathology result showed schistosomiasis. Postoperatively, the patient had a slight improvement in terms of lower extremity weakness (flickering of the digits). However, there was no improvement in his continence ability.

Clinical discussion

The most common neurological manifestation of Schistosoma mansoni infection is myelopathy, which includes subacute myeloradiculopathy and acute transverse myelitis. The cauda equina and conus medullaris are the areas most frequently affected.

Conclusion

When spinal schistosomiasis presents itself as a mimicking spinal tumour, it poses a complex clinical challenge that necessitates a comprehensive interdisciplinary approach to ensure accurate diagnosis and effective treatment. It is imperative for healthcare practitioners to enhance their knowledge and awareness of this uncommon parasitic infection, particularly in regions where it is prevalent.

Serous macular detachment in ocular toxoplasmosis: A review

Ocular toxoplasmosis, a disease of the eye caused by the protozoan parasite Toxoplasma gondii, represents a common cause of posterior uveitis. The Authors review the current Literature regarding the uncommon presentation of ocular toxoplasmosis as macular serous retinal detachment (SRD). It is imperative to keep in mind that inflammatory SRD is a possible presentation of toxoplasmic retinochoroiditis. Underestimation of this clinical scenario and treatment with steroids alone without appropriate antiparasitic drugs, could lead to devastating consequences.

Fulminant Pneumonia Due to Reactivation of Latent Toxoplasmosis in a Cat-A Case Report

Toxoplasma (T.) gondii is an obligate intracellular parasite with felids, including domestic cats, as definitive hosts. In immunocompetent individuals, T. gondii infection is usually asymptomatic. However, under immunosuppression, it may have severe pathological impacts, which often result from the reactivation of a chronic infection. In this case study, a 21-month-old female domestic shorthair cat-diagnosed with primary immune-mediated hemolytic anemia three months prior and treated with cyclosporine and prednisolone-presented with acute tachypnea, dyspnea, diarrhea, and anorexia. Thoracic radiography suggested severe pneumonia. Testing for Mycoplasma spp., Anaplasma spp., Ehrlichia spp., and lungworm infection was negative. Serology for T. gondii revealed seroconversion of IgG, but not of IgM, indicating previous exposure to T. gondii. The cat remained stable but tachypneic for three days, followed by an acute onset of dyspnea and clinical deterioration, after which euthanasia was elected. Numerous protozoa were present in a postmortem transtracheal bronchoalveolar lavage and fine-needle aspiration of the lung. Microsatellite typing classified the extracted DNA as T. gondii type II variant TgM-A. This case demonstrates that T. gondii reactivation, leading to fulminant pneumonia, can be a sequela of immunosuppressive treatment in cats and should, therefore, be considered as a differential diagnosis in immunosuppressed cats with acute-onset respiratory signs. Rapid diagnosis may prevent fatal consequences.

Misdiagnosis of HIV With Toxoplasmosis Encephalopathy With Progressive Memory Loss as the Initial Symptom: A Case Report

Toxoplasmosis encephalopathy (TE) is a kind of encephalopathy parasitic disease caused by Toxoplasma gondii. It is the most common opportunistic for central system infection in patients with acquired immunodeficiency syndrome (AIDS) or human immunodeficiency virus. Without early diagnosis and proper treatment, this opportunistic infection can be life-threatening. The common clinical manifestations of the disease include altered mental state, epilepsy, cranial nerve damage, paresthesia, cerebellar signs, meningitis, motor disorders, and neuropsychiatry. The most common presentation in about 75% of cases is a subacute episode of focal neurological abnormalities such as hemiplegia, personality changes, or aphasia. Imaging needs to be differentiated from multiple sclerosis, lymphoma, and metastases. We report a case of acquired immune deficiency syndrome complicated with toxoplasma encephalopathy with rapid progressive memory loss as the initial symptom and misdiagnosed as multiple sclerosis. Through the comprehensive analysis of the clinical symptoms and imaging examination of this disease, we hope to enhance the confidence of clinicians in the diagnosis of this disease.

Infections in the Developing Brain: The Role of the Neuro-Immune Axis

Central nervous system (CNS) infections occur more commonly in young children than in adults and pose unique challenges in the developing brain. This review builds on the distinct vulnerabilities in children's peripheral immune system (outlined in part 1 of this review series) and focuses on how the developing brain responds once a CNS infection occurs. Although the protective blood-brain barrier (BBB) matures early, pathogens enter the CNS and initiate a localized innate immune response with release of cytokines and chemokines to recruit peripheral immune cells that contribute to the inflammatory cascade. This immune response is initiated by the resident brain cells, microglia and astrocytes, which are not only integral to fighting the infection but also have important roles during normal brain development. Additionally, cytokines and other immune mediators such as matrix metalloproteinases from neurons, glia, and endothelial cells not only play a role in BBB permeability and peripheral cell recruitment, but also in brain maturation. Consequently, these immune modulators and the activation of microglia and astrocytes during infection adversely impact normal neurodevelopment. Perturbations to normal brain development manifest as neurodevelopmental and neurocognitive impairments common among children who survive CNS infections and are often permanent. In part 2 of the review series, we broadly summarize the unique challenges CNS infections create in a developing brain and explore the interaction of regulators of neurodevelopment and CNS immune response as part of the neuro-immune axis.

Risk factors associated with seropositivity for Toxoplasma gondii in population-based studies among immunocompromised patients (pregnant women, HIV patients and children) in West African countries, Cameroon and Gabon: a meta-analysis

Toxoplasmosis in immunocompromised individuals can be life threatening. The information needed for proper control and management strategies in endemic West African countries is lacking, hence a systematic review and meta-analysis were performed. This study aimed to determine the seroprevalence of anti-Toxoplasma gondii among pregnant women, HIV/AIDs and children in West Africa, Cameroon and Gabon. The epidemiology of the disease published between 1984 and 2019 using PubMed, Web of Science, Ovid MEDLINE, AJOL and Google Scholar databases were identified. Studies that met the inclusion criteria of Toxoplasma gondii infections under the preferred reporting items for systematic reviews and meta-analyses (PRISMA) checklist were analysed. A total of 58 eligible studies were selected for meta-analysis. These studies considered 18,674 hosts and an overall pooled seroprevalence of anti-T. gondii antibodies were 45.4, 39.0 and 29.5% for pregnant women, HIV/AIDS patients and children, respectively. Pooled seroprevalence was highest in Gabon and lowest in Mali for pregnant women while highest levels of seropositivity for anti-T. gondii antibodies for HIV/AIDS individuals and children were both observed in Ghana. The major risk factors associated with anti-T. gondii seropositivity were gravida status, contact with cats, consumption of raw vegetables and /fruits, age and CD4 counts. More studies are needed to determine seroconversion rate. Improved sensitization among immunocompromised patients on T. gondii and its risk factors will be an efficient method to reducing the prevalence of the disease. One Health interventions involving transdisciplinary, integrative research and capacity building are necessary to address the problem of toxoplasmosis in West Africa.

Seroprevalence of toxoplasma gondii infection: An umbrella review of updated systematic reviews and meta-analyses

Objectives:

Toxoplasmosis is one of the neglected parasitic disease in humans and animals that produced via toxoplasma gondii. This study we implemented an umbrella review of all existing systematic reviews, meta-analyzing studies to apprise, and summarize seroprevalence of human toxoplasmosis in worldwide.

Methods:

The search was carried out in databases including: Pub Med, Google Scholar, Science Direct, Scopus, Web of Science, Cochrane, and global health from their start dates until December 2018 in Persian and English language. A total of 21 systematics review and meta-analysis met the inclusion criteria of umbrella review. The Q test and the I² statistic were used to evaluate heterogeneities. Quality assessment were performed and made use of the AMSTAR tool.

Results:

The estimated pooled seroprevalence of T. gondii infection in blood donors, Immunocompromised patients, childbearing age women, general population, newborns and children, pregnant women and overall was 33% (95% CI, 29.0–38.0%), 42.0% (95 CI, 34.0–49.0%), 32.0% (CI, 26.0–38.0%), 42.0% (CI, 38.0–45.0%), 4.0% (CI, 2.0–5.0%), 40.0% (CI,37.0–44.0%), and 36% (CI, 24.0–48.0%), respectively.

Conclusion:

The results of our umbrella review show a higher seroprevalence of T. gondii infection in immunocompromised patients, general population, pregnant women, blood donors, childbearing age women, and newborn groups, respectively. Routine serologic screening test and health education by primary care physicians for Toxoplasmosis is recommended to be conducted in high-risk groups in the endemic region.

Depression and Toxoplasma gondii infection: assess the possible relationship through a seromolecular case-control study

Depression disorder is one of the most common psychological recognitions that characterized by sadness, low self-confidence, and disinterest in every activity. Considering evidence showing the effects of toxoplasmosis on the psychological disease, this study conducted to investigate the serological and molecular aspects of Toxoplasma gondii infection among patients with depression. In this study, after selecting the patients with depression and control groups under the supervision of a psychologist, the blood samples were collected and the serum samples and buffy coat were separated. The specific anti-Toxoplasma IgG antibodies in serum samples were evaluated using the commercial ELISA kit. Then the desired region of the Toxoplasma B1 gene was amplified using the specific primers. To confirm the specificity of primers to amplify the B1 gene of Toxoplasma, the extracted PCR product was sequenced. The overall prevalence of toxoplasmosis in patients with depression was 59.8 and 60.19% by ELISA and PCR, respectively. In the control group, the prevalence of Toxoplasma was 56.3 and 40.2% by serology and PCR. There was a significant correlation between the prevalence of toxoplasmosis and depression. Moreover, a significant difference was found between the variables of age, sex, kind of nutrition, level of education and toxoplasmosis among the two cases and control groups. The higher prevalence of Toxoplasma infection among patients with depression compared with the control group indicates the probable impact of this parasite on depression and exacerbates its symptoms, which requires special attention of specialist physicians and patient's relatives.

Schistosomiasis: Still a Cause of Significant Morbidity and Mortality

Tropical diseases remain severe threats to global health with acute or chronic debility. Public health issues are regularly monitored and reported by the WHO. Conditions with high prevalence and virulence such as Schistosomiasis or Malaria still need active treatment. Advances over the decades in the treatment and management of Schistosomiasis have reduced morbidity and mortality in patients. However, poverty, adverse environments, lack of education and awareness, with parasites and vectors that can thrive if uncontrolled, remain issues for the successful global eradication of Schistosomiasis. From the disease's discovery in 1850, the author relates historical details to its current status. Several countries previously affected, including Japan and Tunisia, have eliminated the disease while others seek the same goal. Africa remains the most severely affected continent with vulnerable women and children, although the infection persists in South America and the Far East of Asia as well. Realistic improvements for continuing health conditions are vogue and emphasized for those at risk or afflicted by the infection, illustrating success models of concerted efforts of extirpation. Constant proximity to infected water, with a parasite host, are hurdles in reducing exposure. Effective medication for acute treatment is available, and prophylaxis by vaccination is promising. Where endemic Schistosomiasis is prevalent, significant morbidity and mortality have far-reaching complications in multiple human organ systems, including irreversible pulmonary hypertension, renal, genitourinary, central nervous system conditions, and neoplasia. Two hundred and thirty million people are estimated to have contracted Schistosomiasis globally, with up to 700 million still at risk of infection, and 200,000 deaths occur annually. The disease may be more prevalent than thought after newer tests have shown increased sensitivity to pathological antigens. The author discusses infectivity risks, investigations, prognosis, treatment, and management, as well as morbidity and mortality.

The One Health Approach to Toxoplasmosis: Epidemiology, Control, and Prevention Strategies

One Health is a collaborative, interdisciplinary effort that seeks optimal health for people, animals, plants, and the environment. Toxoplasmosis, caused by Toxoplasma gondii, is an intracellular protozoan infection distributed worldwide, with a heteroxenous life cycle that practically affects all homeotherms and in which felines act as definitive reservoirs. Herein, we review the natural history of T. gondii, its transmission and impacts in humans, domestic animals, wildlife both terrestrial and aquatic, and ecosystems. The epidemiology, prevention, and control strategies are reviewed, with the objective of facilitating awareness of this disease and promoting transdisciplinary collaborations, integrative research, and capacity building among universities, government agencies, NGOs, policy makers, practicing physicians, veterinarians, and the general public.

[Infections of the central nervous system by protozoa, helminths and fungi]

A plethora of different parasites and fungi can lead to infections of the central nervous system (CNS) and cause different clinical symptoms and outcomes depending on the pathogen and the anatomic location of the infection. The diagnosis and treatment of these eukaryotic infections is challenging. The prevalence of CNS infections depends on many factors, including geographical location, living conditions, genetic background and the immune status of the individual. In Germany, infections of the CNS by fungi and parasites are rare but can lead to considerable morbidity. Some parasitic and fungal CNS infections are becoming increasingly more prevalent and clinically relevant due to the increasing number of immunocompromised people. Case fatality rates of these infections, which are difficult to diagnose and to treat, are high. This article provides an overview of a subjective selection of parasitic and fungal infections of the CNS relevant to clinical practice in Germany and presents the diagnostic and therapeutic options.

Disseminated Strongyloidiasis: Breaking Brain Barriers

Strongyloides stercoralis (SS) is one of the most overlooked helminthic infections despite being highly endemic in tropical and subtropical areas. In immunocompromised patients, especially those on long-term steroids, infection can often escalate to fatal dissemination into major organs. We present a compendium of two immunocompromised patients, who were on high-dose steroids and presented with worsening neurological status. Cerebrospinal fluid analysis was notable for larvae of SS as diagnosed by direct visualization. A syndrome of SS hyperinfection with dissemination was made after stool, and sputum samples also revealed SS larvae. SS is an elusive disease and should be considered early on, especially in endemic regions like India. Early diagnosis and prompt initiation of antihelminthic therapy is indispensable for favorable outcomes.

Seroprevalence of Toxoplasma gondii infection in cancer patients: A systematic review and meta-analysis

Toxoplasmosis, caused by Toxoplasma gondii, is a great public health concern in cancer patients, which can induce serious pathological effects. This systematic review and meta-analysis was performed to evaluate the worldwide seroprevalence rate of T. gondii infection among cancer patients. A search was conducted on five electronic databases that reported data on T. gondii seroprevalence in cancer patients. The searching process resulted in the inclusion of 57 studies. The results showed that T. gondii had the pooled prevalence of 30.8% in cancer patients using a random-effect model (95% CI: 26.3-35.6). Cancer patients had a higher overall prevalence of T. gondii infection, compared to those without cancer. Furthermore, the odds ratio of toxoplasmosis in cancer patients was 3.1 times, compared to that of controls (95% CI: 2.5-3.8, P < 0.0001). Toxoplasmosis had a higher prevalence in females (40%) than in males (33%). Furthermore, the age group of upper 40 years had the highest prevalence infection rate (30%). In addition, a significant association was also observed between toxoplasmosis infection and year (P < 0.001), type of cancer (P < 0.001), country (P < 0.001), gender (P < 0.001), age (P = 0.006) and diagnostic method (P < 0.001) in cancer patients. Considering the high prevalence of T. gondii infection in cancer patients and its serious outcomes, the researchers are suggested to carry out further studies to prevent and control toxoplasmosis among this population.

Infections in the immunocompromised child

Prevention and management of opportunistic infections in children is particularly relevant in an era demonstrating an increased prevalence of immunocompromising conditions. The presence of an unusual organism which results in serious infection in a child should therefore always raise the consideration of immune compromise. The more common opportunistic infections have become easier to recognize in recent times due to improved awareness and more refined diagnostic testing. Targeted treatment is usually followed by long-term prophylactic medication. The impact of these conditions on patient outcome is of clear significance and certainly warrants further discussion.

A Guide to Utilization of the Microbiology Laboratory for Diagnosis of Infectious Diseases: 2018 Update by the Infectious Diseases Society of America and the American Society for Microbiology

The critical nature of the microbiology laboratory in infectious disease diagnosis calls for a close, positive working relationship between the physician/advanced practice provider and the microbiologists who provide enormous value to the healthcare team. This document, developed by experts in laboratory and adult and pediatric clinical medicine, provides information on which tests are valuable and in which contexts, and on tests that add little or no value for diagnostic decisions. This document presents a system-based approach rather than specimen-based approach, and includes bloodstream and cardiovascular system infections, central nervous system infections, ocular infections, soft tissue infections of the head and neck, upper and lower respiratory infections, infections of the gastrointestinal tract, intra-abdominal infections, bone and joint infections, urinary tract infections, genital infections, and other skin and soft tissue infections; or into etiologic agent groups, including arthropod-borne infections, viral syndromes, and blood and tissue parasite infections. Each section contains introductory concepts, a summary of key points, and detailed tables that list suspected agents; the most reliable tests to order; the samples (and volumes) to collect in order of preference; specimen transport devices, procedures, times, and temperatures; and detailed notes on specific issues regarding the test methods, such as when tests are likely to require a specialized laboratory or have prolonged turnaround times. In addition, the pediatric needs of specimen management are also emphasized. There is intentional redundancy among the tables and sections, as many agents and assay choices overlap. The document is intended to serve as a guidance for physicians in choosing tests that will aid them to quickly and accurately diagnose infectious diseases in their patients.

Enteroparasitosis infections among renal transplant recipients in Khartoum state, Sudan 2012-2013

Objectives

Renal transplantation procedure markedly increased over the past few decades. The risk of harboring parasitic diseases may affect transplant recipients during life expectancy. We aimed in this study to determine the enteroparasitosis frequency among renal transplant recipients in Khartoum state, Sudan. A case–control hospital-based study performed between November 2012 and May 2013, on 300 renal transplant recipients attending Sudanese Kidney Association hospital in Khartoum state, Sudan, along with 300 normal healthy individuals matching the case in age and sex. Stool samples were collected for parasitological studies.

Results

Out of the 300 renal transplant recipients: 242 (80.7%) were males mean age 43 ± 11.28 and 58 (19.3%) were females mean age 41 ± 13.41. Intestinal parasitic infection was observed in 118 participants and the overall frequency was 19.7%; of which 64 were cases (21.3%) and 54 (18.0%) were controls. Eight different species of intestinal parasites were identified; Entamoeba histolytica/dispar (7.5%), Entamoeba coli (6.5%), Giardia lambelia (3.2%), Cryptosporidium parvum (1.2%), Ascaris lumbricoides (0.6%), Enterobius vermicularis (0.3%), (0.2%) for each of Strongyloides stercoralis and Hymenolepis nana.

Solid Organ Transplant and Parasitic Diseases: A Review of the Clinical Cases in the Last Two Decades

The aim of this study was to evaluate the occurrence of parasitic infections in solid organ transplant (SOT) recipients. We conducted a systematic review of literature records on post-transplant parasitic infections, published from 1996 to 2016 and available on PubMed database, focusing only on parasitic infections acquired after SOT. The methods and findings of the present review have been presented based on the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) checklist. From data published in the literature, the real burden of parasitic infections among SOT recipients cannot really be estimated. Nevertheless, publications on the matter are on the increase, probably due to more than one reason: (i) the increasing number of patients transplanted and then treated with immunosuppressive agents; (ii) the “population shift” resulting from immigration and travels to endemic areas, and (iii) the increased attention directed to diagnosis/notification/publication of cases. Considering parasitic infections as emerging and potentially serious in their evolution, additional strategies for the prevention, careful screening and follow-up, with a high level of awareness, identification, and pre-emptive therapy are needed in transplant recipients.

Seroepidemiology of Toxoplasma gondii infection in patients with liver disease in eastern China

The role of the protozoan parasite Toxoplasma gondii in the pathogenesis of liver disease has recently gained much interest. The aim of this study was to determine the prevalence and risk factors associated with T. gondii infection in patients with liver disease from three cities in Shandong and Henan provinces, China. A case-control study was conducted from December 2014 to November 2015 and included 1142 patients with liver disease and 1142 healthy controls. Serum samples were collected from all individuals and were examined with enzyme-linked immunosorbent assay for the presence of anti-T. gondii IgG and IgM antibodies. Information on the demographics, clinical, and lifestyle characteristics of the participants was collected from the medical records and by the use of a questionnaire. The prevalence of anti-T. gondii IgG was 19·7% in patients with liver disease compared with 12·17% in the controls. Only 13 patients had anti-T. gondii IgM antibodies compared with 12 control individuals (1·14% vs. 1·05%, respectively). The highest seroprevalence was detected in patients with liver cancer (22·13%), followed by hepatitis patients (20·86%), liver cirrhosis patients (20·42%), and steatosis patients (20%). Multivariate logistic regression analysis indicated that consumption of raw meat (odds ratio (OR) = 1·32; 95% confidence interval (CI) 1·01-1·71; P = 0·03) and source of drinking water from wells (OR = 1·56; 95% CI 1·08-2·27; P = 0·01) were independent risk factors for T. gondii infection in liver disease patients. These findings indicate that T. gondii infection is more likely to be present in patients with liver disease. Therefore, efforts should be directed toward health education of populations at high risk of T. gondii infection and measures should be taken to protect vulnerable patients with liver disease.

Central Nervous System Infections

This chapter provides an overview of infectious syndromes, pathogens, and diagnostic testing modalities for central nervous system infections in the immunocompromised host.

Toxoplasma gondii Infection in Immunocompromised Patients: A Systematic Review and Meta-Analysis

Toxoplasma gondii has been suggested as an important opportunistic pathogen in immunocompromised patients. We conducted a global meta-analysis to assess the prevalence and odds ratios (ORs) of T. gondii infection in immunocompromised individuals. Electronic databases were reviewed for T. gondii infection in HIV/AIDS patients, cancer patients, and transplant recipients, and meta-analyses were conducted to calculate overall estimated prevalence and ORs using random or fixed-effects models. Totally, 72 eligible studies were included. The estimated pooled prevalence of T. gondii infection in immunocompromised patients and the control was 35.9 and 24.7% (p < 0.001), with an OR of 2.24, i.e., 42.1 and 32.0% for HIV/AIDS patients and the control (p < 0.05), 26.0 and 12.1% for cancer patients and the control (p < 0.001), and 42.1 and 34.5% for transplant recipients and the control (p > 0.05), whose estimated pooled ORs were 1.92 (95% CI, 1.44-2.55), 2.89 (95% CI, 2.36-3.55), and 1.51 (95% CI, 1.16-1.95), respectively. This study is the first to demonstrate that the immunocompromised patients are associated with higher odds of T. gondii infection, and appropriate prevention and control measures are highly recommended for these susceptible populations.

Toxoplasma gondii infection in schizophrenia and associated clinical features

The belief that latent toxoplasmosis is asymptomatic has been questioned, in particular due to the repeated highlighted link between the Toxoplasma gondii infection and an increased incidence of schizophrenia. However, to understand this relationship, the effect of infection with Toxoplasma gondii on the severity of schizophrenia has been poorly studied. Our work focused on comparing the prevalence of Toxoplasma infection between schizophrenic patients and healthy controls, as well as comparing the clinical features and the demographic characteristics between Toxoplasma-seronegative and Toxoplasma-seropositive patients with schizophrenia. The rate of IgG antibody in the schizophrenia patients was 74.8% compared 53.8% in controls. Patients with schizophrenia had a significantly higher mean of serum IgG antibodies to T. gondii compared to controls. The seropositive male patients had a higher age of disease onset, a higher BPRS score, a greater negative PANSS score and a lower GAF score than the seronegative male patients. These results suggest a higher severity of clinical symptoms in the male patients with schizophrenia. This study provides further evidence to the hypothesis that exposure to Toxoplasma may be a risk factor for schizophrenia. Moreover, toxoplasmosis in men with schizophrenia may lead to more severe negative and cognitive symptoms and a less favorable course of schizophrenia.

A case of fatal gastrointestinal haemorrhage due to hyperinfection with Strongyloides stercoralis

Strongyloides stercoralis is an intestinal nematode with a complex life cycle. It is usually asymptomatic in healthy host however it may be a life threatening condition in immunocompromised patients when hyperinfection is associated with disseminated disease. However, reports of gastric involvement are rare. This is a case report of fatal gastrointestinal hemorrhage due to hyperinfection with S. stercoralis in a Burmawi male patient after brief corticosteroid therapy.

SEROPREVALENCE AND RISK FACTORS ASSOCIATED WITH Toxoplasma gondii INFECTION AMONG RURAL COMMUNITIES IN NORTHERN IRAN

Toxoplasmosis is the fourth most common cause of hospitalization and the second cause of death due to food-borne infections. We conducted a cross-sectional study to determine the prevalence, disease awareness and risk factors associated with toxoplasmosis among rural communities in Northern Iran. Data were obtained from serological testing and from participant^'s questionnaires and were analyzed using a logistic regression. Of the 630 participants, 465 (73.8%), and 12 (1.9%) had IgG and both IgG and IgM anti-Toxoplasma gondii antibodies, respectively. In the logistic regression analysis, T. gondii seropositivity was associated with the following factors: age, occupation, consumption of undercooked meat, and of unwashed raw vegetables or fruits (p < 0.001). Our study showed a high prevalence of T. gondii infection in the general population of Northern Iran. A health program is needed to increase the public awareness of toxoplasmosis, and its associated risk factors.

Seroprevalence of Toxoplasma gondii IgG and IgM antibodies and associated risk factors in women of child-bearing age in Njinikom, NW Cameroon

Background

Toxoplasmosis is a widely distributed zoonotic disease, caused by the protozoan parasite Toxoplasma gondii. T. Infections can result in stillbirths, abortions or congenital defects during pregnancy, as well as toxoplasmic encephalitis in HIV/AIDS patients. This study aimed to determine the seroprevalence and risk factors for T. gondii infection in women seeking antenatal and medical care in the locality of Njinikom, North West of Cameroon.

Methods

We conducted a cross-sectional study from August to December 2014 consecutively enrolling 178 consenting women aged 15 to 49 years attending antenatal care or medical check-ups at the hospital. A questionnaire survey was administered to study participants and potential risk factors for Toxoplasma exposure sought. Venous blood was collected and serum from each participant analysed for T. gondii infection as evidenced by the presence of anti-T. gondii IgG and IgM antibodies detected using the indirect enzyme-linked immunosorbent assay (ELISA) technique. The proportion of anti-T. gondii antibody positivity calculated as the percentage of antibody seropositivity to T. gondii antigens. Predictors of T. gondii infection were analysed by univariate and multivariate regression and association with T. gondii seropositivity assessed. Epi-Info 3.5.4 was used for statistical analyses. A p < 0.05 was considered significant for all analyses.

Results

The seroprevalence of anti-T. gondii antibodies (IgM or IgG) were 54.5 % (97/178). Among seropositive women, 88.7 % (86/97), 30.9 % (30/97), and 19.6 % (19/97) were respectively seropositive for IgG antibody, IgM antibody and both IgM and IgG antibodies. Among the risk factors evaluated, only the consumption of raw or undercooked meat (p = 0.02) was observed to be an independent risk factor of T. gondii infection. The consumption of unwashed vegetables and fruits was significant (p = 0.01) only with simple logistic regression analysis.

Conclusions

Our findings suggest recent T. gondii exposure is high in our study population, and may constitute a significant risk factor for stillbirths, abortions or congenital defects during pregnancy in women attending antenatal care, or toxoplasmic encephalitis in those who are immunosuppressed such as in HIV/AIDS. Education and screening of HIV-positive individuals and pregnant women for T. gondii infection may be important primary prevention strategies in this population.

Cerebro-meningeal infections in HIV-infected patients: a study of 116 cases in Libreville, Gabon

BACKGROUND

Cerebro-meningeal pathology is common in human immunodeficiency virus (HIV) infection and the aetiology is often difficult to ascertain with certainty.

OBJECTIVE

To describe the major suspected and identified causes of meningeal or encephalitic syndromes in HIV infection in Libreville, Gabon.

METHODS

A descriptive study using clinical records of patients hospitalised in the Department of Medicine in the Military Hospital of Libreville (Gabon) between January 2006 and May 2010. Clinical features were evaluated using multivariable logistic regression to evaluate association with the outcome of a clinical improvement or death.

RESULTS

The most frequent neurological symptoms were reduced level of consciousness (54.3%), headache (55.2%), motor deficit (38.7%), and convulsions (36.2%). Cerebral toxoplasmosis represented 64.7% of diagnoses, followed by cryptococcal neuromeningitis in 12.9% of cases. Tuberculoma was diagnosed in 4 cases and lymphoma in 2 cases. In 9.5% of cases, no aetiology was determined. Toxoplasmosis treatment led to clinical improvement in 69.3% of cases with suspected cerebral toxoplasmosis. Overall mortality was 39.7%.

CONCLUSION

The diagnosis of neurological conditions in HIV positive patients is difficult, particularly in a low-resource setting. A trial of treatment for toxoplasmosis should be initiated first line with all signs of neurological pathology in a patient infected with HIV.

Toxoplasma gondii infection in interstate truck drivers: a case-control seroprevalence study

Background

Infection with Toxoplasma gondii can be acquired via the ingestion of undercooked or raw meat containing tissue cysts, or via ingestion of water contaminated with oocysts. Professional long distance truck driving may have epidemiological importance for food-borne infections since drivers eat out of home and in places where hygiene and cooking practices are uncertain. We aimed to determine whether interstate truck drivers in Durango, Mexico have an increased risk of infection with T. gondii as indicated by seropositivity; and to determine the socio-demographic, work, clinical, and behavioral characteristics associated with T. gondii seropositivity in interstate truck drivers.

Methods

Through a case–control study design, 192 truck drivers and 192 controls from the general population of the same region matched by gender and age were examined with enzyme-linked immunoassays for the presence of anti-Toxoplasma IgG and IgM antibodies. Socio-demographic, work, clinical and behavioral characteristics from the truck drivers were obtained.

Results

Anti-T. gondii IgG antibodies were found in 23 (12.0%) of 192 truck drivers and in 13 (6.8%) of 192 controls (OR = 21.0; 95% CI: 1.23-358.38; P = 0.002). Anti-T. gondii IgM antibodies were found in 7 (3.6%) cases and in 7 (3.6%) controls (P = 1.00). The seroprevalence of T. gondii infection was higher in drivers with reflex impairment than in those without this impairment (4/13, 30.8% vs 19/179, 10.6%, respectively; P = 0.05), and in drivers with hearing impairment than in those without this impairment (3/7, 42.9% vs 20/185, 10.8%, respectively; P = 0.03). Multivariate analysis of work and behavioral characteristics of truck drives showed positive associations of T. gondii exposure with trips to the south of Mexico (OR = 3.11; 95% CI: 1.02-9.44; P = 0.04) and consumption of horse meat (OR = 5.18; 95% CI: 1.62-16.55; P = 0.005).

Conclusions

Results suggest that interstate truck drivers may have an increased risk for T. gondii infection, and that T. gondii exposure may be impacting neurological functions in truck drivers. Contributing factors for T. gondii exposure should be taken into account for the design of optimal prevention measures against T. gondii infection.

Metabolische Störungen

Im folgenden Kapitel werden die verschiedenen metabolischen Störungen betrachtet. Zunächst wird auf die allgemeinen und spezifischen neurologischen Komplikationen bei Organtransplantation eingegangen. Dann geht es um die metabolischen Enzephalopathien: Störungen der Gehirntätigkeit bei angeborenen und erworbenen Stoffwechselerkrankungen im engeren Sinn, Elektrolytstörungen, Hypovitaminosen, zerebrale Folgen einzelner Organdysfunktionen, zerebrale Hypoxien, Endotheliopathien und Mitochondropathien. Anschließend werden das Alkoholdelir und die Wernicke-Enzephalopathie erörtert. Bei zahlreichen akuten Erkrankungen von Gehirn, Rückenmark und peripherem Nervensystem treten typische Störungen vegetativer Systeme auf, deren Erkennung und Therapie insbesondere bei Intensivpatienten eine vitale Bedeutung haben kann: die autonomen Störungen. Bei der zentralen pontinen Myelinolyse kommt es zu einer akuten, vorwiegend fokal-symmetrischen Demyelinisierung im Hirnparenchym. Auch Basalganglienerkrankungen können intensivmedizinisch relevant werden. Und schließlich wird die akute Stressreaktion betrachtet, die aufgrund der vielfältigen metabolischen und endokrinen Veränderungen bei kritischen Erkrankungen entsteht. Gerade das RCVS als neuere Krankheitsentität und wichtige Differenzialdiagnose zur Vaskulitis des ZNS verdient einen eigenen Platz, in diesem Unterkapitel werden ebenfalls verwandte Syndrome wie die hypertensive Enzephalopathie und das PRES abgehandelt.

Overview of the effect and epidemiology of parasitic central nervous system infections in African children

Infections of the central nervous system are a significant cause of neurologic dysfunction in resource-limited countries, especially in Africa. The prevalence is not known and is most likely underestimated because of the lack of access to accurate diagnostic screens. For children, the legacy of subsequent neurodisability, which affects those who survive, is a major cause of the burden of disease in Africa. Of the parasitic infections with unique effect in Africa, cerebral malaria, neurocysticercosis, human African trypanosomiasis, toxoplasmosis, and schistosomiasis are largely preventable conditions, which are rarely seen in resource-equipped settings. This article reviews the current understandings of these parasitic and other rarer infections, highlighting the specific challenges in relation to prevention, diagnosis, treatment, and the complications of coinfection.

Transcriptional analysis of murine macrophages infected with different Toxoplasma strains identifies novel regulation of host signaling pathways

Most isolates of Toxoplasma from Europe and North America fall into one of three genetically distinct clonal lineages, the type I, II and III lineages. However, in South America these strains are rarely isolated and instead a great variety of other strains are found. T. gondii strains differ widely in a number of phenotypes in mice, such as virulence, persistence, oral infectivity, migratory capacity, induction of cytokine expression and modulation of host gene expression. The outcome of toxoplasmosis in patients is also variable and we hypothesize that, besides host and environmental factors, the genotype of the parasite strain plays a major role. The molecular basis for these differences in pathogenesis, especially in strains other than the clonal lineages, remains largely unexplored. Macrophages play an essential role in the early immune response against T. gondii and are also the cell type preferentially infected in vivo. To determine if non-canonical Toxoplasma strains have unique interactions with the host cell, we infected murine macrophages with 29 different Toxoplasma strains, representing global diversity, and used RNA-sequencing to determine host and parasite transcriptomes. We identified large differences between strains in the expression level of known parasite effectors and large chromosomal structural variation in some strains. We also identified novel strain-specifically regulated host pathways, including the regulation of the type I interferon response by some atypical strains. IFNβ production by infected cells was associated with parasite killing, independent of interferon gamma activation, and dependent on endosomal Toll-like receptors in macrophages and the cytoplasmic receptor retinoic acid-inducible gene 1 (RIG-I) in fibroblasts.

Toxoplasma gondii infection and suicide attempts: a case-control study in psychiatric outpatients

The association of Toxoplasma gondii infection with suicide attempts has been scarcely evaluated. Two hundred eighty-three psychiatric outpatients (156 patients with history of suicide attempt and 127 control patients without history of suicide attempt) were examined with enzyme-linked immunoassays for Toxoplasma immunoglobulin G (IgG) and IgM antibodies. Seroprevalences of Toxoplasma IgG and IgM in the cases and the controls were similar: 7 (4.5%) and 3 (1.9%) vs. 10 (7.9%) and 3 (2.4%) (p = 0.23 and p = 0.55), respectively. In contrast, the Toxoplasma IgG levels higher than 150 IU/ml were more frequently observed in the cases than in the controls (100% vs. 50%, respectively; p = 0.04). The seroprevalence of Toxoplasma infection increased with age and with the number of suicide attempts. Toxoplasma seropositivity was associated with reflex impairment, national trips, and snake meat consumption. Our results suggest that although seroprevalence of Toxoplasma infection is not associated with suicide attempts, a high anti-Toxoplasma antibody level is, therefore warranting further research.

Co-morbid infections in Hansen's disease patients in the United States: considerations for treatment

120 patients attending a Hansen's disease public health satellite clinic were evaluated for selected latent co-morbidities, consisting of strongyloidiasis, Chagas disease, hepatitis B, HIV, and tuberculosis, and potential exacerbation by immunosuppressive therapy. Implications for treatment of Hansen's disease are discussed.

A guide to utilization of the microbiology laboratory for diagnosis of infectious diseases: 2013 recommendations by the Infectious Diseases Society of America (IDSA) and the American Society for Microbiology (ASM)(a)

The critical role of the microbiology laboratory in infectious disease diagnosis calls for a close, positive working relationship between the physician and the microbiologists who provide enormous value to the health care team. This document, developed by both laboratory and clinical experts, provides information on which tests are valuable and in which contexts, and on tests that add little or no value for diagnostic decisions. Sections are divided into anatomic systems, including Bloodstream Infections and Infections of the Cardiovascular System, Central Nervous System Infections, Ocular Infections, Soft Tissue Infections of the Head and Neck, Upper Respiratory Infections, Lower Respiratory Tract infections, Infections of the Gastrointestinal Tract, Intraabdominal Infections, Bone and Joint Infections, Urinary Tract Infections, Genital Infections, and Skin and Soft Tissue Infections; or into etiologic agent groups, including Tickborne Infections, Viral Syndromes, and Blood and Tissue Parasite Infections. Each section contains introductory concepts, a summary of key points, and detailed tables that list suspected agents; the most reliable tests to order; the samples (and volumes) to collect in order of preference; specimen transport devices, procedures, times, and temperatures; and detailed notes on specific issues regarding the test methods, such as when tests are likely to require a specialized laboratory or have prolonged turnaround times. There is redundancy among the tables and sections, as many agents and assay choices overlap. The document is intended to serve as a reference to guide physicians in choosing tests that will aid them to diagnose infectious diseases in their patients.

Seroepidemiology of infection with Toxoplasma gondii in migrant agricultural workers living in poverty in Durango, Mexico

BACKGROUND

Migrant agricultural workers are a group of people living in poverty with poor housing, sanitary conditions and hygiene practices. Little is known about the epidemiology of infection with Toxoplasma gondii in migrant agricultural workers.

METHODS

We investigated the presence of anti-Toxoplasma IgG and IgM antibodies in 173 migrant workers hired for seasonal agricultural work in Durango State in northern Mexico using enzyme-linked immunoassays.

RESULTS

Of the 173 migrant workers (mean age 34.82 ± 14.01 years), 50 (28.9%) had anti-Toxoplasma IgG antibodies and 36 (20.8%) had anti-Toxoplasma IgM antibodies. Seroprevalence was not influenced by gender, age, birth place, or educational level. In contrast, seroprevalence was significantly higher in workers residing in rural areas than those in urban or suburban areas. Migrant workers suffering from memory impairment, dizziness, or syncope had significantly higher seroprevalence of anti-T. gondii IgG antibodies than those without such clinical features. Logistic regression analysis showed that T. gondii exposure was positively associated with consumption of unwashed raw vegetables (OR = 2.39; 95% CI: 1.06-5.35; P = 0.03) and low frequency of eating out of home (OR = 3.87; 95% CI: 1.43-10.42; P = 0.007), and negatively associated with national trips (OR = 0.30; 95% CI: 0.13-0.65; P = 0.003) and consumption of raw milk (OR = 0.40; 95% CI: 0.18-0.87; P = 0.02). Other behavioral characteristics including consumption of meat or untreated water were not associated with T. gondii infection.

CONCLUSIONS

This is the first report of T. gondii infection in internal migrant agricultural workers living in poverty. Results deserve further investigation of causal relations between clinical symptoms and infection, and may be useful for optimal planning of preventive measures.

Human schistosomiasis: clinical perspective: review

The clinical manifestations of schistosomiasis pass by acute, sub acute and chronic stages that mirror the immune response to infection. The later includes in succession innate, TH1 and TH2 adaptive stages, with an ultimate establishment of concomitant immunity. Some patients may also develop late complications, or suffer the sequelae of co-infection with other parasites, bacteria or viruses. Acute manifestations are species-independent; occur during the early stages of invasion and migration, where infection-naivety and the host's racial and genetic setting play a major role. Sub acute manifestations occur after maturity of the parasite and settlement in target organs. They are related to the formation of granulomata around eggs or dead worms, primarily in the lower urinary tract with Schistosoma haematobium, and the colon and rectum with Schistosoma mansoni, Schistosoma japonicum, Schistosoma intercalatum and Schistosoma mekongi infection. Secondary manifestations during this stage may occur in the kidneys, liver, lungs or other ectopic sites. Chronic morbidity is attributed to the healing of granulomata by fibrosis and calcification at the sites of oval entrapment, deposition of schistosomal antigen-antibody complexes in the renal glomeruli or the development of secondary amyloidosis. Malignancy may complicate the chronic lesions in the urinary bladder or colon. Co-infection with salmonella or hepatitis viruses B or C may confound the clinical picture of schistosomiasis, while the latter may have a negative impact on the course of other co-infections as malaria, leishmaniasis and HIV. Prevention of schistosomiasis is basically geared around education and periodic mass treatment, an effective vaccine being still experimental. Praziquantel is the drug of choice in the treatment of active infection by any species, with a cure rate of 80%. Other antischistosomal drugs include metrifonate for S. haematobium, oxamniquine for S. mansoni and Artemether and, possibly, Mirazid for both. Surgical treatment may be needed for fibrotic lesions.

Clinical use of anti-TNF therapy and increased risk of infections

Biologics such as antitumor necrosis factor (anti-TNF) drugs have emerged as important agents in the treatment of many chronic inflammatory diseases, especially in cases refractory to conventional treatment modalities. However, opportunistic infections have become a major safety concern in patients on anti-TNF therapy, and physicians who utilize these agents must understand the increased risks of infection. A literature review of the published data on the risk of bacterial, viral, fungal, and parasitic infections associated with anti-TNF therapy was performed and the clinical presentation, diagnostic tests, management, and prevention of opportunistic infections in patients receiving anti-TNF therapy were reviewed. Awareness of the therapeutic potential and associated adverse events is necessary for maximizing therapeutic benefits while minimizing adverse effects from anti-TNF treatments. Patients should be adequately vaccinated when possible and closely monitored for early signs of infection. When serious infections occur, withdrawal of anti-TNF therapy may be necessary until the infection has been identified and properly treated.

Seroprevalence and risk factors for Toxoplasmosis in HIV infected and non-infected individuals in Bahir Dar, Northwest Ethiopia

Background

Toxoplasmosis, a zoonotic disease distributed worldwide, is an infection caused by the ubiquitous obligatory intracellular coccidian protozoan organism, Toxoplasma gondii. It is a major public health concern because the disease is serious in terms of mortality or physical and /or psychological sequellae in patients with HIV disease. The aim of the study was to assess the seroprevalence of Toxoplasma gondii IgG and IgM antibodies and associated risk factors in HIV infected and non-infected individuals attending Felege Hiwot referral hospital, Bahir Dar, Northwest Ethiopia.

Methods

A cross sectional study was conducted at Felege Hiwot referral hospital, Bahir Dar, Amhara National Regional State. Venous blood samples were collected from 103 HIV infected pre anti-retroviral therapy patients at Felege Hiwot referral hospital and 101 HIV negative apparently healthy voluntary blood donors at the blood bank. Serum samples were analyzed for anti-Toxoplasma gondii IgG and IgM antibodies using a commercially available ELISA kit. Socio-demographic and associated risk factors for Toxoplasmosis from each individual were also obtained and the data was analyzed using SPSS version 18.

Results

Of the examined HIV seropositive individuals, 87.4% (90/103) and 10.7% (11/103) were positive for anti-T. gondii IgG and IgM antibodies, respectively. Multivariate analysis using logistic regression showed that anti-T. gondii seropositivity was independently significantly associated with undercooked or raw meat consumption (adjusted OR=5.73, 95% CI=1.35-24.39; P=0.02) and having contact with cat (adjusted OR= 4.29, 95% CI=1.08-16.94; P=0.04) in HIV positive individuals. In HIV negative apparently healthy blood donors, prevalence of anti-T. gondii antibodies were 70.29% and 2.97% for IgG and IgM, respectively. Multivariate analysis showed that undercooked or raw meat consumption (adjusted OR=6.45, 95% CI=2.16-19.28; p=0.001) and sex (OR=6.79, 95% CI=2.14-21.60; p=0.001) were independently significantly associated with anti-T. gondii IgG seropositivity, with a significantly higher number of males affected than females.

Conclusion

The present findings showed a high sero-prevalence of anti-T. gondii antibodies in HIV infected pre-ART and HIV non-infected apparently healthy blood donors in Bahir Dar. Consumption of undercooked or raw meat might greatly contribute towards acquiring T. gondii infection in HIV infected pre-ART and HIV non-infected apparently healthy blood donors. It may be appropriate to include routine serological screening test for determination of anti-T. gondii antibodies in HIV infected pre-ART individuals and HIV negative apparently healthy blood donors. In addition, health education towards avoiding eating undercooked and raw meat, and avoiding contact with cats were recommended.

Immunodiagnosis of CNS parasitic infections

The nature of many parasitic infections of the central nervous system (CNS) requires immunodiagnosis to confirm presumptive diagnoses. The CNS is the primary site of parasite infection for some parasitic organisms and for others, neurological infection occurs only in immunocompromised hosts. Still other parasites cause ectopic infections of the CNS and occur very rarely. This review concentrates on laboratory diagnosis of diseases that are caused by parasites with a primary predilection for the CNS. Emphasis is placed on laboratory diagnostic methods that are used and suitable for clinical diagnosis, rather than a comprehensive review of all the experimental methods that have been reported in the literature. Immunodiagnosis is not appropriate for the diagnosis of all parasitic infections of the CNS; in those cases, alternative diagnostic methods are presented, but not discussed in detail. In some instances potential new antigens or methods are presented, particularly if adoption of these methods is expected in the near future.

Central Nervous System Strongyloidiasis and Cryptococcosis in an HIV-Infected Patient Starting Antiretroviral Therapy

We report a case of Strongyloides stercoralis hyperinfection syndrome with central nervous system involvement, in a patient with late human immunodeficiency virus (HIV) infection starting antiretroviral therapy, in whom Strongyloides stercoralis larvae and Cryptococcus neoformans were isolated antemortem from cerebrospinal fluid. Our patient was not from an endemic region for the parasite, so strongyloidiasis was not originally suspected. For this reason, we conclude that Strongyloides stercoralis infection should be suspected in HIV-infected patients starting antiretroviral therapy in order to avoid potential fatal outcomes.

Seroepidemiology of Toxoplasma gondii infection in elderly people in a northern Mexican city

Whereas it is well-known that the seroprevalence of infection with Toxoplasma gondii increases with age, details of the seroepidemiology of infection in elderly people are largely unknown. Anti-T. gondii IgG and IgM antibody levels were determined in 483 subjects aged ≥60 years old in Durango City, Mexico, using enzyme-linked immunosorbent assays. Socio-demographic, clinical, and behavioral characteristics from each participant were also obtained. In total, 58 (12%) of 483 participants (mean age 70.35±6.63 years) had anti-T. gondii IgG antibodies, and 14 (2.9%) also had anti-T. gondii IgM antibodies. Seroprevalence of infection varied significantly with age, birthplace, and educational level. Seroprevalence increased with age, especially in women (p=0.01), and was higher in subjects born outside of Durango State than those born within Durango State (p=0.008). Seroprevalence was higher in men with up to 12 years of education than in men with more than 12 years of education (p=0.01). Multivariate analysis of behavioral data showed a positive association of T. gondii infection with the presence of cats in the neighborhood, as well as consumption of boar, pigeon, iguana, and armadillo meats, and chorizo. Gender-specific analysis showed the described associations in women but not in men. In contrast, consumption of beef showed a negative association with T. gondii infection. This is the first report of the seroprevalence and contributing factors for T. gondii infection in elderly people, and of an association of the consumption of armadillo and iguana meats with T. gondii infection. Our results will provide the basis for the design of optimal preventive measures against T. gondii infection.

Seroepidemiology of Toxoplasma gondii infection in Tepehuanos in Durango, Mexico

The epidemiology of Toxoplasma gondii infection is known to depend on a number of behavioral factors, including contact with animals and eating habits. The epidemiology in specific populations (i.e., in indigenous ethnic groups) is not well studied. We therefore investigated the presence of anti-Toxoplasma IgG and IgM antibodies in 156 Tepehuanos, an indigenous ethnic group in Durango State in northern Mexico, using ELISAs. Of the 156 Tepehuanos (mean age 31.03±16.71 years), 35 (22.4%) had anti-Toxoplasma IgG antibodies. IgG levels of 14-99, 100-150, and >150 IU/mL were found in 15 (42.9%), 1 (2.8%), and 19 (54.3%) anti-Toxoplasma IgG-positive Tepehuanos, respectively. Also, 15 (9.6%) subjects had anti-Toxoplasma IgM antibodies. Male Tepehuanos aged 31-50 years showed a significantly higher frequency of exposure to T. gondii than female Tepehuanos of the same age. Seroprevalence of anti-T. gondii IgM antibodies was significantly higher in Tepehuanos without education than those with 7-12 years of education. Tepehuanos suffering from frequent headaches had significantly higher seroprevalences of anti-T. gondii IgG and IgM antibodies than those without this clinical feature. In addition, Tepehuanos suffering from hearing impairment had significantly higher seroprevalence of anti-T. gondii IgM antibodies than those without this clinical feature. Logistic regression analysis did not show an association of T. gondii exposure with any behavioral characteristics, including contact with cats or eating habits. The seroprevalence of T. gondii exposure in Tepehuanos is comparable to that reported in other populations in North America; however, seroprevalence in the largely rural Tepehuanos is higher than that reported in a nearby urban center. Toxoplasma may be impacting the health of Tepehuanos. This is the first report of T. gondii infection in Tepehuanos, and the results should prove useful for the design of preventive measures.

Infections in Leukemia and Hematopoietic Stem Cell Transplantation

Infections are one of the most common complications in patients diagnosed with leukemia and serve as a major obstacle to treatment. Through the early 1970s, infections were the most common cause of death in patients diagnosed with acute leukemia, but improvement in treatment and supportive care over the past few decades, coupled with expanded prophylaxis and prevention regimens, have led to reduction in both the frequency and severity of infections. Regardless, due in part to an aging cancer population and the diversity of cancer treatments and procedures, infectious diseases remain a major cause of morbidity and mortality in patients with leukemia.

Detection of IgM and IgG anti-Toxoplasma antibodies in renal transplant recipients using ELFA, ELISA and ISAGA methods: comparison of pre- and post-transplantation status

In the transplant recipient patients receive immunosuppressive therapy, the possibility of reactivation of the old infection or acquisition of infection from a donor's tissue increases. In this study, IgM and IgG anti-Toxoplasma immunoglobulins seroconversion in renal transplant recipients (RTRs) have been evaluated before and after transplantation. This is a prospective cohort study on a total of 102 RTRs. Two serum samples were obtained from each patient. The first was taken before administration of any immunosuppressive drugs such as corticosteroids and the second was taken 3 months after transplantation. The IgM and IgG anti-Toxoplasma antibodies were assayed by enzyme-linked flourescence assay (ELFA) and enzyme-linked immunosorbent assay (ELISA) techniques. IgM/immunosorbent agglutination assay (ISAGA) method has also been used. All RTRs were tested for toxoplasmosis before and after transplantation. ELFA identified 65 (63·7%) pre-transplantation samples as IgG+ and did not detect any positive IgM samples. However, IgM was detected in three (2·9%) post-transplantation samples by this method. Forty-nine (48%) pre-transplantation samples were reported IgG+ by ELISA and no IgM positive sample was identified by this method. ELISA has detected two (1·9%) IgM-positive reactions in post-transplantation samples. By IgM/ISAGA method, we have detected no IgM positive reactions in pre-transplantation samples, whereas 3 months later (second sampling) IgM antibody was detected in 3 (2·9%) cases. Secondary toxoplasmosis infection was observed in 30 cases per 1000 RTRs, which indicates that screening for toxoplasmosis infection should be performed in developed countries for these patients. On the other hand, as the risk of re-active toxoplasmosis infection exists in developing nations, they should consider the necessary preventive measures to control this condition.

First century of Chagas' disease: an overview on novel approaches to nifurtimox and benzonidazole delivery systems

Hundred years after the discovery of Chagas' disease, there is a lack of effective treatment to control this neglected disease caused by the parasite Trypanosoma cruzi. The transmission is primarily through vector-borne blood transfusion or during pregnancy, producing high mortality and morbidity among poor people in many countries of Latin America. In the last decades, the efforts have been focused mainly on the elimination of vectors. At the same time, screening of blood donors in order to avoid transfusional transmission has been improved all over the world. However, Chagas' disease is still a major public health problem, with estimates of nearly 90 million people at risk of infection and more than eight million infected in 18 endemic countries. Despite the high incidence in endemic regions and the dissemination of neglected diseases in North America and Europe, to date, there are only two drugs developed and prescribed for the treatment of Chagas' disease, nifurtimox (tablets of 120 mg) and benzonidazole (tablets of 100 mg). In this review, different approaches carried out in the last decades for developing novel pharmaceutical formulations for the delivery of nifurtimox and benznidazole are discussed.