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

PURPOSE: Toxoplasma gondii is one of the most widespread parasites in the human population globally. Several modes of its transmission have been proposed: some are well-researched and confirmed, others remain unconfirmed. One unconfirmed hypothesis pertains to potential transmission of Toxoplasma gondii via oral sex (fellatio) in humans. A recent study found tissue cysts in the semen of men with latent toxoplasmosis. Therefore, we aimed to test the hypothesis of Toxoplasma gondii transmission through oral sex experimentally. METHODS: Eighty-two laboratory mice were orally administered semen samples from 41 men with latent toxoplasmosis. These semen samples were examined for the presence of Toxoplasma gondii DNA using PCR. RESULTS: We detected Toxoplasma gondii DNA in three of the 41 semen samples from men with latent toxoplasmosis. Oral administration of semen samples to laboratory mice did not result in parasite transmission. CONCLUSION: We have not demonstrated the transmission of Toxoplasma to mice by oral exposure to semen from infected men. While this does not conclusively rule out the possibility of such transmission in humans, the results suggest that, if it does occur, this mode of transmission is likely infrequent.

Detection of persistent low IgG avidity-an interpretative problem in the diagnosis of acute toxoplasmosis.

OBJECTIVES: For the proper diagnosis of toxoplasmosis it is essential to determine the stage of the infection, for which the most preferred method is IgG avidity test. The avidity index (AI) should initially be low (AI≤0.3) in the acute phase and increase during the infection. However, persistent low avidity can occur in patients with latent toxoplasmosis, which can complicate the interpretation of the results. The aim of the study is to explain the causes of this phenomenon. METHODOLOGY: A retrospective study was carried out with 717 serum samples collected from 442 patients from the categories of pregnant and non-pregnant women, men, and newborns + infants (age < 0.5 year). The trends of AI kinetics were evaluated in repeatedly examined patients. The frequency of cases with low avidity was compared in individual categories of patients and in groups of people with acute and non-acute toxoplasmosis. RESULTS: The proportion of patients with initially low avidity was 42.1% in the acute toxoplasmosis group while it was 13.0% in the non-acute groups. In uninfected newborns with anti-Toxoplasma antibodies transmitted from the mother, a decrease in IgG avidity levels over time was observed, resulting in 29.2% of samples showing low (improper) avidity. While the dynamics of IgG avidity and the frequency of cases of improperly low avidity were similar in men and pregnant and non-pregnant women, the category of newborns and infants differed substantially for these indicators. CONCLUSIONS: Due to acceptable specificity and negative predictive value, high avidity can rule out acute toxoplasmosis, but moderate sensitivity complicates the possibility of its confirmation. The results of the avidity test must be interpreted in the context of the results of other methods.

Serological Diagnostics of Lyme Borreliosis: Comparison of Universal and Borrelia Species-Specific Tests Based on Whole-Cell and Recombinant Antigens.

The study compares diagnostic parameters of different commercial serological kits based on three different antigen types and correlates test results with the status of the patient's Borrelia infection. In total, 8 IgM and 8 IgG kits were tested, as follows: enzyme-linked immunosorbent assay (ELISA) (Euroimmun) based on whole-cell antigen, 3 species-specific enzyme immunoassays (EIAs) (TestLine), Liaison chemiluminescence (DiaSorin), ELISA-Viditest (Vidia), EIA, and Blot-Line (TestLine) using recombinant antigens. All tests were performed on a panel of 90 samples from patients with clinically characterized borreliosis (53 with neuroborreliosis, 32 with erythema migrans, and 5 with arthritis) plus 70 controls from blood donors and syphilis patients. ELISA based on whole-cell antigens has superior sensitivity and superior negative predictive value and serves as an excellent screening test, although its specificity and positive predictive values are low. Species-specific tests have volatile parameters. Their low sensitivity and low negative predictive value handicap them in routine diagnostics. Tests with recombinant antigens are characterized by high specificity and high positive predictive value and have a wide range of use in diagnostic practice. Diagnostic parameters of individual tests depend on the composition of the sample panel. Only a small proportion of contradictory samples giving both negative and positive results is responsible for discrepancies between test results. Correlation of test results with the patient's clinical state is limited, especially in the erythema migrans group with high proportions of negative and contradictory results. In contrast, IgG test results in the neuroborreliosis group, which are more concordant, show acceptable agreement with Borrelia status.

Absence of Borrelia burgdorferi in the myocardium of subjects with normal left ventricular systolic function: a study using PCR and electron microscopy.

BACKGROUND: Several studies have demonstrated the presence of the Borrelia burgdorferi (Bb) genome in the myocardium of patients with dilated cardiomyopathy (DCM). To further support a causal relationship between the presence of Bb in the heart muscle and the development of DCM, demonstration of the absence of Bb in the myocardium of subjects with normal left ventricular (LV) systolic function is needed. AIM: To determine the prevalence of Bb by polymerase chain reaction (PCR) and electron microscopy (EM) in individuals with normal LV systolic function and no history suggestive of myocarditis. METHODS: We investigated 50 patients (67 ± 9 years, 15 women) with normal LV ejection fraction (EF) ≥ 50% undergoing cardiac surgery. During surgery, four samples from the right atrial appendage were obtained and subsequently examined by PCR and EM for the presence of Bb, and by immunohistochemistry to detect inflammatory cells. Serological testing of antibodies against Bb was also performed. RESULTS: Neither PCR nor EM detected Bb in any of the subjects. Immunohistological examination revealed myocardial inflammation in 2 individuals (4%). Serological analysis by enzyme-linked immunosorbent assay demonstrated IgM antibodies against Bb in 4% and IgG antibodies in 12% of the study cohort; Western blot revealed IgM as well as IgG positivity in 14% of patients. CONCLUSIONS: The absence of Bb in the myocardium of individuals who undergo cardiac surgery and have normal LV systolic function supports the idea of Bb pathogenicity in the development of DCM.

Short-term stability of Borrelia garinii in cerebrospinal fluid.

The aim of our study was to find out the optimal conditions for short-term storage of cerebrospinal fluid (CSF) samples for direct diagnosis of Lyme disease. A mixture of Borrelia-negative CSFs spiked with a defined amount of cultured Borrelia garinii was used. Borrelia stability was investigated over 7 days at four different temperatures [room temperature (RT), +4, -20 and -70 °C]. Quantitative changes in CSF Borrelia were measured by quantitative PCR (qPCR), and morphological changes in the spirochetes were observed by transmission electron microscopy (TEM). These qPCR results were statistically evaluated. We found +4 °C to be an optimal temperature for short-term storage of CSF samples intended for TEM observation. There was no significant difference between the temperatures tested in the average quantity of Borrelia measured by qPCR. On the contrary, electron optical diagnosis of frozen samples and samples stored at RT showed destructive morphological changes and decreased spirochete counts. Our results show that optimal conditions for the pre-analytical phase of investigation of one type of material can differ depending on the diagnostic method employed.

Recent-onset dilated cardiomyopathy associated with Borrelia burgdorferi infection.

BACKGROUND: Several recent small studies have suggested a causal link between Lyme disease and dilated cardiomyopathy (DCM) by demonstrating the presence of the Borrelia burgdorferi (Bb) genome in the myocardium of patients with recent-onset DCM. The aim of this study was to further investigate the effect of targeted antibiotic treatment of Bb-related recent-onset DCM in a larger cohort of patients. PATIENTS AND METHODS: We performed endomyocardial biopsy (EMB) in 110 individuals (53 ± 11 years, 34 women) with recent-onset unexplained DCM, and detected the Bb genome in 22 (20 %) subjects. Bb-positive patients were subsequently treated with intravenous ceftriaxone for 21 days in addition to conventional heart failure medication. RESULTS: At the 1-year follow-up, a significant improvement in left ventricular (LV) ejection fraction (26 ± 6 vs. 44 ± 12 %; p < 0.01) and a decrease in LV end-diastolic (69 ± 7 vs. 63 ± 11 mm; p < 0.01) and end-systolic (61 ± 9 vs. 52 ± 4 mm; p < 0.01) diameters were documented. Moreover, a significant improvement in heart failure symptoms (NYHA class 3.4 ± 0.6 vs. 1.5 ± 0.7; p < 0.01) was also observed. CONCLUSION: Targeted antibiotic treatment of Bb-related recent-onset DCM in addition to conventional heart failure therapy is associated with favorable cardiac remodeling and improvement of heart failure symptoms.

Detection of Borrelia burgdorferi sensu lato in endomyocardial biopsy specimens in individuals with recent-onset dilated cardiomyopathy.

AIMS: Recent studies in patients with dilated cardiomyopathy (DCM) have detected the genome of Borrelia burgdorferi sensu lato (BBSL) in endomyocardial biopsy (EMB) specimens using a qualitative polymerase chain reaction (PCR), suggesting a causal link between Lyme disease and DCM in areas in which Lyme disease is endemic. We aimed to study this relationship using a comprehensive molecular analysis detecting BBSL in EMB samples. METHODS AND RESULTS: We performed a comprehensive histopathological, immunohistochemical, ultrastructural, and molecular analysis targeting cardiotropic viruses and BBSL in EMB specimens of 41 individuals with recent-onset DCM and 15 controls with end-stage coronary artery disease. Specifically, quantitative PCR and electron microscopy of EMB specimens were employed. In addition, autoantibodies and manifestation of autoimmune diseases were evaluated in both groups. Individuals with recent-onset DCM presented more frequently with myocardial BBSL persistence as compared with the control group (24% vs. 0%, P = 0.035). In contrast, the prevalence of parvovirus B19 and cytomegalovirus was similar in both groups. Sequence analysis of borrelial DNA revealed the following genospecies: Borrelia burgdorferi sensu stricto in three patients (30%), Borrelia afzelii in two patients (20%), and Borrelia garinii in four patients (40%), the results being inconclusive in one case. BBSL-positive DCM patients had a higher prevalence of organ-specific autoimmune diseases in comparison with the remaining DCM patients (50% vs. 16%, P = 0.030). CONCLUSION: Myocardial persistence of BBSL may be involved in the pathophysiology of DCM in individuals living in areas in which Lyme disease is endemic.