Primary toxoplasmosis with critical illness and multi-organ failure in an immunocompetent young man

Mutual regulations between Toxoplasma gondii and type I interferon

In the decades since the discovery, Type I interferon (IFN-I) has been intensively studied for their antiviral activity. However, increasing evidences suggest that it may also play an important role in the infection of Toxoplasma gondii, a model organism for intracellular parasites. Recent studies demonstrated that the induction of IFN-I by the parasite depends on cell type, strain genotype, and mouse strain. IFN-I can inhibit the proliferation of T. gondii, but few studies showed that it is beneficial to the growth of the parasite. Meanwhile, T. gondii also can secrete proteins that impact the pathway of IFN-I production and downstream induced interferon-stimulated genes (ISGs) regulation, thereby escaping immune destruction by the host. This article reviews the major findings and progress in the production, function, and regulation of IFN-I during T. gondii infection, to thoroughly understand the innate immune mechanism of T. gondii infection, which provides a new target for subsequent intervention and treatment.

Parasitic and Fungal Triggers of Cytokine Storm Syndrome

Infections caused by parasites and fungi can trigger the cytokine storm syndrome (CSS). These infections causing CSS can occur together with acquired immunodeficiencies, lymphomas, the use of immunosuppressive medications, transplant recipients, cancer, autoinflammatory, and autoimmune diseases or less frequently in healthy individuals. Histoplasma, Leishmania, Plasmodium, and Toxoplasma are the most frequent organisms associated with a CSS. It is very important to determine a previous travel history when evaluating a patient with a CSS triggered by these organisms as this may be the clue to the causal agent. Even though CSS is treated with specific therapies, an effort to find the causal organism should be carried out since the treatment of the infectious organism may stop the CSS. Diagnosing a CSS in the presence of parasitic or fungal sepsis should also lead to the study of an altered cytotoxic or hemophagocytic response in the susceptible host.

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.

Cerebral toxoplasmosis requiring urgent brain biopsy

A 39-yerar-old man was admitted to our hospital with behavioral disturbances and generalized headaches. He was diagnosed with CNS toxoplasmosis after performing a brain biopsy. He found to be HIV positive with a CD4 of 14/uL He was started on ant toxoplasmosis along with antiretroviral therapy. He presented 6 weeks after discharge with worsening headache thought to be related to relapse of toxoplasmosis. However, he found to have severe anemia related to CMV-induced gastrointestinal bleeding. He was started on anti-cytomegalovirus drugs and has finally achieved significant improvement.

Recurrent seizures during acute acquired toxoplasmosis in an immunocompetent traveller returning from Africa

INTRODUCTION

We report an unusual case of acute acquired toxoplasmosis (AAT) presenting as lymphadenopathy and recurrent seizures in an immunocompetent 15-year-old boy.

MATERIALS AND METHODS

The patient reported an 18-day vacation to Africa (Ethiopia), 39 days prior to the first seizure. Electroencephalogram (EEG) showed sporadic single-spike or sharp-wave paroxysms and the magnetic resonance imaging (RMI) of the brain was negative. The serology for T. gondii was compatible with an acute infection defined as positive for both toxoplasma-specific IgG and IgM and a low avidity (6 %), confirmed by a reference laboratory. The patient reported other two episodes of seizures, occurring 7 days apart. He was treated with pyrimethamine plus sulfadiazine and leucovorin for 4 weeks, with an improvement of lymphadenitis and normalization of EEG. After 5 months, new seizures were reported and a diagnosis of epilepsy was done. Toxoplasma polymerase chain reaction (PCR) of cerebrospinal fluid (CSF) and blood were negative. A treatment with valproic acid was started, obtaining control of the neurological disease.

CONCLUSION

Awareness of this neurologic manifestation by clinicians is required, also in immunocompetent patients. The relationship between toxoplasmosis and recurrent seizure needs to be investigated by new studies.