Recurrent amebic liver abscesses over a 16-year period: A case report

Background: Amebic liver abscess is a rare disease in high-income countries. Recurrence of amebic liver abscess is even rarer with only a few previous reports. Here we present a patient who developed three subsequent amebic liver abscesses over a sixteen-year period. Case presentation: A Caucasian male developed recurrent amebic liver abscesses, when aged 23, 27 and 39 years. Only on the first occasion did this coincide with a recent visit to the tropics. The patient received adequate treatment during each episode. Possible explanations are persistent asymptomatic carrier state, cysts passage in his family, re-infection or chance. Conclusion: We describe the unusual case of a healthy male who developed recurrent amebic liver abscesses over a long period despite adequate treatment. Possible pathophysiological explanations are explored

Interference with the Host Haemostatic System by Schistosomes

Schistosomes, parasitic flatworms that cause the tropical disease schistosomiasis, are still a threat. They are responsible for 200 million infections worldwide and an estimated 280,000 deaths annually in sub-Saharan Africa alone. The adult parasites reside as pairs in the mesenteric or perivesicular veins of their human host, where they can survive for up to 30 years. The parasite is a potential activator of blood coagulation according to Virchow's triad, because it is expected to alter blood flow and endothelial function, leading to hypercoagulability. In contrast, hepatosplenic schistosomiasis patients are in a hypocoagulable and hyperfibrinolytic state, indicating that schistosomes interfere with the haemostatic system of their host. In this review, the interactions of schistosomes with primary haemostasis, secondary haemostasis, fibrinolysis, and the vascular tone will be discussed to provide insight into the reduction in coagulation observed in schistosomiasis patients.Interference with the haemostatic system by pathogens is a common mechanism and has been described for other parasitic worms, bacteria, and fungi as a mechanism to support survival and spread or enhance virulence. Insight into the mechanisms used by schistosomes to interfere with the haemostatic system will provide important insight into the maintenance of the parasitic life cycle within the host. This knowledge may reveal new potential anti-schistosome drug and vaccine targets. In addition, some of the survival mechanisms employed by schistosomes might be used by other pathogens, and therefore, these mechanisms that interfere with host haemostasis might be a broad target for drug development against blood-dwelling pathogens. Also, schistosome antithrombotic or thrombolytic molecules could form potential new drugs in the treatment of haemostatic disorders

Manual blood exchange transfusion does not significantly contribute to parasite clearance in artesunate-treated individuals with imported severe Plasmodium falciparum malaria

Background: Exchange transfusion (ET) has remained a controversial adjunct therapy for the treatment of severe malaria. In order to assess the relative contribution of ET to parasite clearance in severe malaria, all patients receiving ET as an adjunct treatment to parenteral quinine or to artesunate were compared with patients treated with parenteral treatment with quinine or artesunate but who did not receive ET. ET was executed using a standardized manual isovolumetric exchange protocol. Methods. All patients in the Rotterdam Malaria Cohort treated for severe P. falciparum malaria at the Institute for Tropical Diseases of the Harbour Hospital between 1999 and 2011 were included in this retrospective follow-up study. Both a two-stage approach and a log-linear mixed model approach were used to estimate parasite clearance times

Association of Eumycetoma and Schistosomiasis

Eumycetoma is a morbid chronic granulomatous subcutaneous fungal disease. Despite high environmental exposure to this fungus in certain regions of the world, only few develop eumycetoma for yet unknown reasons. Animal studie

Predictive value of lymphocytopenia and the neutrophil-lymphocyte count ratio for severe imported malaria

Background: Lymphocytopenia has frequently been described in patients with malaria, but studies on its association with disease severity have yielded conflicting results. The neutrophil/lymphocyte count ratio (NLCR) has been introduced as a parameter for systemic inflammation in critically ill patients and was found, together with lymphocytopenia, to be a better predictor of bacteraemia than routine parameters like C-reactive protein and total leukocyte count. In the present study, the predictive value of the NLCR and lymphocytopenia for severe disease was evaluated in patients with imported malaria. Methods. All patients diagnosed with malaria at the Harbour Hospital between January 1§ssup§st§esup§ 1999 and January 1§ssup§st§esup§ 2012 with differential white cell counts determined within the first 24 hours after admission were included in this retrospective study. Severe malaria was defined according to the WHO criteria. The performance of the NLCR and lymphocytopenia as a marker of severe malarial disease was compared back-to-back with that of C-reactive protein as a reference biomarker. Results: A total of 440 patients (severe falciparum malaria n = 61, non-severe falciparum malaria n = 259, non-falciparum malaria n=120) were included in the study. Lymphocytopenia was present in 52% of all patients and the median NLCR of all patients was 3.2. Total lymphocyte counts and NLCR did not differ significantly between groups. A significant correlation of total leukocyte count and NLCR, but not lymphocyte count, with parasitaemia was found. ROC analysis revealed a good negative predictive value but a poor positive predictive value of both lymphocytopenia and NLCR and performance was inferior to that of C-reactive protein. After complete parasite clearance a significant rise in total leukocyte count and lymphocyte count and a significant decrease in NLCR was observed. Conclusion: The NLCR was found to correlate with parasitaemia, but b

Toxoplasma gondii Serostatus Is not associated with impaired long-term survival after heart transplantation

BACKGROUND: Conflicting data have been reported about the effect of Toxoplasma serostatus on mortality after heart transplantation. Either a positive or a negative recipient Toxoplasma serostatus was found to be associated with increased mortality. METHODS: We evaluated the effects of T. gondii infection on survival of our 582 cardiac allograft recipients operated upon between June 1984 and July 2011. RESULTS: The 258 Toxoplasma seronegative and 324 seropositive recipients differed in age, pretransplantation diagnosis, ischemia time, renal function, donor Toxoplasma serology, and maintenance immunosuppression. After a median follow-up time of 8.3 years (range, 0-26 years), 117 (45%) seronegative and 219 (67%) seropositive patients died. No difference was found in deaths due to cardiac allograft vasculopathy. After adjustment for all relevant clinical characteristics, the recipient Toxoplasma serostatus was not associated with mortality (hazard ratio, 1.21; 95% confidence interval [CI], 0.95-1.54). With the Toxoplasma serostatus combination donor negative/recipient negative as a reference, univariate hazard ratios for the Toxoplasma serostatus combinations were D+/R-0.52 (95% CI, 0.37-0.7

Is paromomycin the drug of choice for eradication of Dientamoeba fragilis in adults?

Dientamoeba fragilis is a debated protozoan parasite that is often detected in stools of patients with chronic gastro-intestinal complaints. A retrospective follow-up study of a large cohort of patients was performed to better understand the natural course of the infection and possible treatment options. D. fragilis was spontaneously cleared in 41% of untreated cases. With an eradication rate of 98%, treatment with paromomycin appeared more effective than treatment with clioquinol (83%) or metronidazole (57%)

Inhibition of Fatty Acid Oxidation as a New Target To Treat Primary Amoebic Meningoencephalitis

Primary amoebic meningoencephalitis (PAM) is a rapidly fatal infection caused by the free-living amoeba Naegleria fowleri The amoeba migrates along the olfactory nerve to the brain, resulting in seizures, coma, and, eventually, death. Previous research has shown that Naegleria gruberi, a close relative of N. fowleri, prefers lipids over glucose as an energy source. Therefore, we tested several already-approved inhibitors of fatty acid oxidation alongside the currently used drugs amphotericin B and miltefosine. Our data demonstrate that etomoxir, orlistat, perhexiline, thioridazine, and valproic acid inhibited growth of N. gruberi We then tested these compounds on N. fowleri and found etomoxir, perhexiline, and thioridazine to be effective growth inhibitors. Hence, not only are lipids the preferred food source for N. gruberi, but also oxidation of fatty acids seems to be essential for growth of N. fowleri Inhibition of fatty acid oxidation could result in new treatment options, as thioridazine inhibits N. fowleri growth in concentrations that can be reached at the site of infection. It could also potentiate currently used therapy, as checkerboard assays revealed synergy between miltefosine and etomoxir. Animal testing should be performed to confirm the added value of these inhibitors. Although the development of new drugs and randomized controlled trials for this rare disease are nearly impossible, inhibition of fatty acid oxidation seems a promising strategy as we showed effectivity of several drugs that are or have been in use and that thus could be repurposed to treat PAM in the future