Western blotting for the diagnosis of congenital toxoplasmosis

Toxoplasmosis is a common congenital infection. It does not usually produce recognizable signs of infection at birth so most infected newborns are not detected by routine clinical examination and remain untreated. Infected children without clinical symptoms should nonetheless be identified and treated as early as possible. Serological diagnosis of congenital toxoplasmosis is quite difficult. The aim of this study was to evaluate the utility of Western blot for the diagnosis of congenital toxoplasmosis. We compared the immunological profiles of mothers and children to differentiate between passively transmitted maternal antibodies and antibodies synthesized by the infants in the first three months of life. The method enabled us to diagnose congenital toxoplasmosis in cases in which the infection had not been detected by classical serology techniques.     

A comparative study of the role of domestic cats and dogs in the epidemiology of toxoplasmosis]

A total of 2643 persons in 5 different regions were examined for toxoplasmosis by the immunofluorescence test and toxoplasmin skin test. The presence in the house of cats and dogs was taken into account. In two of the five regions under study there was revealed an increased incidence of toxoplasmosis in persons keeping cats; this confirmed the role of these animals as a source of toxoplasmosis infection. The absence of such increase in the incidence of the disease in other regions in explained by the character of buildings admitting migration of cats or the presence in the given region of other active sources of infection. Toxoplasmosis incidence in persons who kept or didn't keep dogs displayed no significant difference.     

The placenta: a main role in congenital toxoplasmosis?

Systemic infections, such as toxoplasmosis, acquired during pregnancy can lead to placental infection and have profound effects on the mother-to-child relationship and the success of pregnancy. Placental permeability to Toxoplasma gondii is a main parameter that determines parasite transmission to the foetus, and the use of antibiotics to decrease placental parasite load and prevent congenital toxoplasmosis has been suggested for decades. Although parasitological examination of the placenta at birth is commonly used to diagnose neonatal congenital toxoplasmosis, this approach can be controversial. Here we argue in favour of placental examination for both diagnostic and epidemiological purposes.     

Toxoplasmosis and the epidemiological status of the population. II. The determination of the intensity of toxoplasmosis transmission

The possibility of using the primary epidemiological unit, force of infection, as a criterion for evaluating the intensity of the transfer of toxoplasmosis among the population at the focus of infection has been established. The comparison of data obtained in different regions indicates that the level of the force of infection is, in general, low, but it can vary within a wide range. The problem of the suitability of using the force of infection as a criterion for dividing territories into zones with respect to toxoplasmosis is discussed.     

宠物弓形虫的感染及其防控

弓形虫病是一种世界性分布的人兽共患寄生虫病,对人类,尤其是妇女、儿童危害很大,估计全世界有1/3人受到该病的威胁。孕妇感染弓形虫后导致早产、流产、胎儿发育畸形;弓形虫是免疫功能低下患者的主要死亡原因之一。犬、猫是弓形虫的中间宿主和终末宿主,是人类感染弓形虫的主要来源。随着我国经济的迅速发展和人民生活水平的不断提高,城市中饲养犬、猫作为宠物的人越来越多,人、宠物间的亲密接触增加了弓形虫病传播给人的机会。加强对宠物犬、猫弓形虫病的研究及防控势在必行。本文就弓形虫的危害、宠物犬猫弓形虫感染及其防控措施作以综述。     

Prevalence of ornithosis in the Lithuanian SSR

As a result of immunological examination of 658 domestic ducks of 6 poultry farms and 269 doves caught in Vilnius, antiornithosis antibodies were revealed in 3.1 +/- 0.7% of ducks and in 36.4 +/- 2.9% of doves. They were also found in 20 of 34 wild waterfowl. The causative agent of ornithosis was isolated in virological examination of the organs of a coot. Ornithosis nature of an epizootic outbreak among ducks of a poultry farm was proved by virological examination. The population was examined immunologically (2285 persons) and by intradermal test with the ornithosis antigen (80 persons). Positive specific reactions were revealed in 32.6% of persons engaged in poultry tending, and in 7.6% of other rural population. A case of ornithosis in man engaged in fowling (of doves) for their examination is described.     

Direct evidence of Toxoplasma-induced changes in serum testosterone in mice

Latent toxoplasmosis is known to influence the morphology of infected persons and also increases the probability of the birth of male offspring in both humans and mice. All these traits can be related to the observed differences in the concentration of testosterone between Toxoplasma-infected and Toxoplasma-free subjects. However, it is not possible to decide, using the Toxoplasma-human model, whether toxoplasmosis influences the level of testosterone in the infected host or whether individuals with different levels of testosterone vary in the probability of toxoplasma infection. Here we studied changes in the testosterone levels in the latent phase of toxoplasmosis in laboratory mice artificially infected with cystogenic but relatively virulent strain T38 of T. gondii. We observed decreased testosterone levels in both female and male mice with latent toxoplasmosis in comparison to uninfected controls (P = 0.001). The present results indicate that Toxoplasma infection changes the concentration of serum testosterone in mice and human rather than changed concentration of testosterone influences the probability of the Toxoplasma infection. It is possible that the decrease of testosterone is an adaptive mechanism of infected mice aimed to compensate toxoplasmosis-induced immunosuppression observed during latent Toxoplasma infection.     

Efficacy of the per os immunization and reimmunization of man with staphylococcal anatoxin]

By double immunization of 72 persons and single reimmunization of 38 persons per os with tablets containing 100 BU of purified concentrated staphylococcus toxoid (PCST) it was revealed that this immunization was harmless and the immunological response was adequate. The tablets were intended for application through the oral mucosa (oral) or the intestinal tract (enteral); the immunological response depended on the dose of the preparation and the scheme of administration. A high sensitization of healthy persons examined to staphylococcus was found. There was a tendency to reduction of hypersensitivity after the immunization with staphylococcus toxoid (examination in 6 months) and activation of reactions after the antigen administration (examination in 14 days).     

Seroepidemiological survey of human toxoplasmosis in Osorno, Region X, Chile, 1998]

A serological survey was carried out in Osorno X Region, Chile (40 degrees 21'-40 degrees 46' South lat, and 73 degrees 26' -72 degrees-46' West long.). An indirect hemagglutination test (IHAT) for toxoplasmosis was performed to 305 persons--160 blood donors and 145 with sexually transmitted disease (STD). The age of the surveyed persons (167 males and 138 females) varied between 10 and 72 years. IHAT titers > 16 were considered as positive. The general prevalence was 20.3%--21.2% in blood donors and 19.3% in persons with some STD--with no differences between males and females. However, significant differences between males and females with STD were found (35.6% and 8.1% respectively). No differences between urban and rural inhabitants were found with a slight higher prevalence in the urban ones. No antibodies against Toxoplasma gondii were detected in six AIDS patients. The importance of performing toxoplasmosis immunodiagnosis and individual prophylaxis to avoid the infection in high risk group are recommended.     

Toxoplasmosis: beyond animals to humans

The parasitic zoonosis toxoplasmosis, which was poorly understood before the advent of the HIV epidemic, has become a major clinical problem worldwide. Humans acquire toxoplasmosis from cats, from consuming raw or undercooked meat and from vertical transmission to the foetus through the placenta during pregnancy. Studies of the unique environmental factors in various communities indicate the important roles that eating habits and culture have on the transmission of this infection. The socioepidemiological aspects of toxoplasmosis are thought to be important contributing factors for the spread of this disease. Preventative measures should consider the cultures and beliefs of people in various communities more than solving poverty and giving orthodox health education.     

Sex steroids, pregnancy-associated hormones and immunity to parasitic infection

A wealth of evidence has accumulated that illustrates the ability of sex-associated hormones to influence directly a variety of diverse immunological functions. Thus, it is not surprising that differences have also been noted between the sexes in their relative susceptibility to parasitic infections. Furthermore, during pregnancy, much of the observed maternal immunomodulation, essential for fetal survival, has been attributed to changes in the levels of steroid hormones. These pregnancy-induced alterations in immune function can also have profound effects on the course of parasitic infection. In this article, Craig Roberts, Abhay Satoskar and James Alexander review the immunological basis for differences in the relative susceptibilities of males, non-pregnant females and pregnant females to parasitic infection, particularly leislumaniasis and toxoplasmosis. They also discuss the role of the major sex- and pregnancy-associated hormones in mediating these effects.     

Tuberculosis of the lymphatic nodes and coexisting invasion with Toxoplasma gondii]

Six cases of the peripheral lymphatic nodes tuberculosis with positive serologic reactions to Toxoplasma gondii antigen are presented. It was shown, that independently of a complex of clinical examinations histologic examination is decisive for the diagnosis of lymphatic nodes tuberculosis with coexisting toxoplasmosis. A positive serologic reaction with T. gondii antigen in patients with lymphatic nodes tuberculosis may reflect inactive infection with T. gondii. Use of anti-toxoplasmosis drugs may be not necessary in such cases.     

Factors of occurrence of ocular toxoplasmosis. A review

Acquired and congenital toxoplasmosis are frequently complicated by ocular toxoplasmosis. The diagnosis relies on clinical aspects, response to specific treatment and results of biological assays. The incidence and the prevalence of this complication are difficult to establish precisely and depend on the prevalence of the parasite infection in the general population, and are affected by factors such as type of exposure to the parasite, genetic backgrounds of the parasite and the host, and type of immune response elicited by the parasite.     

Content of A-, G- and M-class immunoglobulins in adults perorally immunized with a liver Sonne dysentery vaccine]

The authors studied the immunological shifts in the blood and saliva of 357 adults immunized with live enteral dysentery Sonne vaccine from a spontaneous mutant according to different schemes (1, 2, 3, 4 injections at 2--3-day intervals. The general level of IgA, IgG, and IgM increased during the immunization; there was also an elevation of the specific antibodies level of these classes in the blood of the persons vaccinated. Accretion was the greatest of IgA both in the blood and in saliva of the immunized persons; this pointed to a marked, chiefly local, immunological activity of the vaccine. As shown, during the immunization the rise and the changes in the antibody level of various immunoglobulin classes differed from such in dysentery infection; in the latter case, along with the IgA-antibodies there was a marked elevation of the IgG- and IgM-antibodies level. It is supposed that there was a possibility of a changed of a 4-time immunization scheme to-3-time one, with increase of intervals between the vaccine administration.     

Toxoplasmosis, distemper, and herpesvirus infection in a skunk (Mephitis mephitis).

A striped skunk (Mephitis mephitis) showing abnormal behavior had histopathologic lesions of toxoplasmosis and canine distemper in addition to intranuclear, eosinophilic inclusions in the reticuloendothelial cells of the spleen, liver and lung. The inclusions, on electron microscopic examination, were compatible with herpesvirus infection.     

Interaction between Helicobacter pylori and Latent Toxoplasmosis and Demographic Variables on Cognitive Function in Young to Middle-Aged Adults

Helicobacter pylori and latent toxoplasmosis are widespread diseases that have been associated with cognitive deficits and Alzheimer’s disease. We sought to determine whether interactions between Helicobacter pylori and latent toxoplasmosis, age, race-ethnicity, educational attainment, economic status, and general health predict cognitive function in young and middle-aged adults. To do so, we used multivariable regression and multivariate models to analyze data obtained from the United States’ National Health and Nutrition Examination Survey from the Centers for Disease Control and Prevention, which can be weighted to represent the US population. In this sample, we found that 31.6 percent of women and 36.2 percent of men of the overall sample had IgG Antibodies against Helicobacter pylori, although the seroprevalence of Helicobacter pylori varied with sociodemographic variables. There were no main effects for Helicobacter pylori or latent toxoplasmosis for any of the cognitive measures in models adjusting for age, sex, race-ethnicity, educational attainment, economic standing, and self-rated health predicting cognitive function. However, interactions between Helicobacter pylori and race-ethnicity, educational attainment, latent toxoplasmosis in the fully adjusted models predicted cognitive function. People seropositive for both Helicobacter pylori and latent toxoplasmosis – both of which appear to be common in the general population – appear to be more susceptible to cognitive deficits than are people seropositive for either Helicobacter pylori and or latent toxoplasmosis alone, suggesting a synergistic effect between these two infectious diseases on cognition in young to middle-aged adults.     

An epidemiologic and immunologic study of measles under conditions of massive immunization against that infection]

Massive measles immunization in Riga led to a marked reduction of measles incidence and to a change of the principal regularities of the epidemic process in this infection. Among those who contracted the disease there was an increase in the percentage of schoolchildren; affection with measles of children attending creches and kindergartens and the intensity of the spread of the infection in them diminished. Selective examination of the immunological efficacy of the living measles vaccine prepared of the (see article) and applied in 1967--1972 demonstrated the presence of specific stimulation of the antibody formation in about 90% of the persons vaccinated. The intensity of humoral immunity in the persons vaccinated did not diminish with the advance of time after the vaccination, and 6--7 years after the vaccination over 90% of the vaccinated individuals were reliably protected from measles. The presence of numerous negative results in carrying out the vaccinations in individual institutions is apparently attributed chiefly to disturbances of the storage regimen of transportation and of the use of the vaccine.     

TGF-β in Toxoplasmosis: Friend or foe?

Toxoplasma gondii (T. gondii) is an obligate intracellular protozoan causing several forms of toxoplasmosis in humans. The main mechanisms that allow the development of the prolonged forms of the disease and its subsequent pathology are yet to be clarified. However, many researchers have hypothesized that immunological and genetic parameters may play crucial roles in the etiology of the disease. Transforming growth factor beta (TGF-β) is a cytokine with a dual role in the regulation of immune responses including those against parasites. However, the relationship between TGF-β and immune responses against T .gondii are not fully understood. The important roles played by TGF-β in the development of Th17 and T regulatory lymphocytes, mucosal immunity and regulation of immune responses have been documented and this provides insights into TGF-β function during parasitic infections such as toxoplasmosis. Therefore, the aim of this review is to collate the current information regarding the status and association of TGF-β with T. gondii infection.     

Control of the risk of human toxoplasmosis transmitted by meat

One-third of the human world population is infected with the protozoan parasite Toxoplasma gondii. Recent calculations of the disease burden of toxoplasmosis rank this foodborne disease at the same level as salmonellosis or campylobacteriosis. The high disease burden in combination with disappointing results of the currently available treatment options have led to a plea for more effective prevention. In this review we describe Toxoplasma as a hazard associated with the consumption of undercooked meat or meat products and provide an analysis of the various options to control the risk of human toxoplasmosis via this source. Monitoring and surveillance programs may be implemented for pre-harvest control of Toxoplasma infection of farm animals, with the reduction of environmental oocyst load as the most important milestone. Alternatively, Toxoplasma safe meat can be obtained through simple post-harvest decontamination procedures, whereby freezing the meat may currently be the best option, although new technologies using irradiation or high-pressure treatment may offer promising alternatives. Influence of culture, religion and food handling customs may predispose a certain type of meat as an important source of infection, indicating that prevention needs to be tailored according to social habits in different regions in the world. The rationale for more stringent control measures to prevent toxoplasmosis both from disease and economic points of view is emphasized.     

HIV infection in the penitentiaries of Ukraine

In connection with a sharp increase of the number of HIV-infected persons in the Ukraine the natural growth of the number of such persons in penitentiary institutions was registered, starting from 1995 (455 persons in 1995, 2,937 persons in 1996, 2,779 persons in 1997 and 173 persons during 5 months of 1998). 83% of HIV infection persons were drug addicts introducing drugs intravenously. In 1997 the strategy of decreasing the risk of infection in penitentiary institutions was worked out in collaboration with UNAIDS experts: repressive and isolation measures were replaced with measures aimed at the "decrease of harm". Special attention is given to circumstances aggravating the epidemic situation in HIV infection, and particularly at the sharp growth of morbidity in tuberculosis and syphilis (10.6 and 10.3 times respectively in 1997 in comparison with 1993). In addition, in 1997 the number of person having drug addiction was noted to increase 2.3 times in comparison with 1993. The necessity of taking constant information and educational measures aimed at decreasing the risk of the spread of HIV infection is emphasized.