Toxoplasmosis in an Immunocompetent Patient

A Report of a Rare Case of a Solitary Ring-Enhancing Lesion in a Patient With Positive Toxoplasma Serology

Ring-enhancing lesions are typically observed in patients with immunosuppression caused by underlying conditions such as HIV/AIDS or cancer. These lesions can arise from various etiologies, including infections, neoplasms, or vascular conditions. This case involves a male in his 30s from South America who presented to the emergency department after experiencing a seizure episode. He had no significant prior medical history and reported that he had not seen a doctor since childhood. A comprehensive workup was initiated during his hospitalization, including brain imaging that revealed a solitary ring-enhancing lesion. The evaluation encompassed brain CT and MRI, along with infectious labs measuring inflammatory and serological markers for several diseases. An infectious disease consultant was engaged to assist in developing a thorough assessment and management plan. Throughout the hospitalization, the patient exhibited a benign physical exam with no neurological deficits, remained afebrile, and displayed insignificant white blood cell counts and negative blood cultures. Serological test results were all negative for HIV, rapid plasma reagin, and tuberculosis, except for a positive Toxoplasma gondii IgG antibody level. This case is noteworthy because the patient presented with a solitary ring-enhancing lesion in the brain resulting from a prior T. gondii infection, despite the absence of documented risk factors for this condition.

Re-Emerging, Under-Recognized Zoonotic, and Neglected Tropical Diseases in Hawai'i

Hawai'i, the United States' most western geographic state in the Pacific, lies between the North and South American continents and the Indo-Pacific regions, including Japan. The tropical environmental conditions of the Hawaiian Islands provide favorable ecosystems for various infectious pathogens, their vectors, and reservoirs. This creates an environment conducive to the transmission of zoonotic diseases affecting both humans and animals. Hawai'i has experienced an increase in dengue, leptospirosis, and murine typhus outbreaks. Furthermore, toxoplasmosis and neuroangiostrongyliasis cases remain prevalent throughout the state, and the putative presence of autochthonous Zika cases identified in a retrospective study may be of national public health concern. Understanding the factors that affect the transmission and distribution of zoonoses is necessary to identify at-risk locations and populations. The One Health approach seeks to understand, report, and interpret these factors and requires collaboration between private and governmental institutions. One Health should focus on neglected tropical diseases (NTD) and prioritize development of interventions to control and prevent the transmission of diseases that spread between animals and humans. This review focuses on the epidemiological and clinical characteristics of under-recognized zoonotic and NTD affecting Hawai'i, including leptospirosis, murine typhus, neuroangiostrongyliasis, toxoplasmosis, dengue, and Zika.

Central Nervous System Tuberculosis Presenting With Multiple Ring-Enhancing Lesions: A Diagnostic Challenge

Mycobacterium tuberculosis (TB) used to be one of the most widespread infections around the world. However, with improvements in sanitation, access to therapy, and increased public health efforts, TB has almost been eliminated from the developed world. While classically located in the lungs, infection can spread to distant sites from either late stage complications or as a sequelae from immunosuppression. In this paper, we present a case of a 53-year-old female who presented with nonspecific neurological complaints and multiple ring-enhancing lesions in the brain who was eventually diagnosed with central nervous system (CNS) tuberculosis after a lengthy workup despite following guideline-directed management. The purpose of this case report is to review an approach for ring-enhancing lesions and clinical considerations for central nervous system tuberculosis and add to the limited body of literature on the subject.

Tubulointerstitial nephritis and uveitis syndrome following meningitis and systemic lymphadenopathy with persistent Toxoplasma immunoglobulin M: a case report

Background

Tubulointerstitial nephritis and uveitis syndrome is a rare lymphocyte-related oculorenal inflammatory disease presumed to be associated with drug use and infectious agents. Toxoplasma gondii is one of such pathogens that could exhibit encephalitis, meningitis, and uveitis in immunocompromised or in some immunocompetent individuals. If the immunoglobulin M of Toxoplasma is positive on screening, the interpretation of the result is not simple, especially when immunoglobulin M stays positive persistently.

Case presentation

A 34-year-old Asian male developed fever, headache, and lymphadenopathy with tenderness, which was initially diagnosed as meningitis. Antibiotics were started, and diclofenac sodium was used for the fever. Although his symptoms were alleviated in a week by the treatment, gradual decline in renal function was noted, prompting a renal biopsy that indicated acute granulomatous interstitial nephritis. A week later, tenderness in both eyes with blurred vision appeared and revealed iritis and keratic precipitations in both eyes; hence, the diagnosis of acute tubulointerstitial nephritis and bilateral uveitis syndrome was made. Toxoplasma gondii-specific immunoglobulin G and immunoglobulin M titers were both positive. Although we could not rule out recent infection of Toxoplasma gondii, which may cause uveitis initially, Toxoplasma immunoglobulin G avidity test indicated a distant infection, which allowed us to rule out meningitis and uveitis as responsible for the complication of recent Toxoplasma gondii infection. Drug-induced lymphocyte stimulation test, or lymphocyte transformation test of diclofenac sodium, was solely positive among the tested drugs. Uveitis was alleviated only with ophthalmic steroid, and renal function returned to normal without administration of systemic steroid.

Conclusions

We experienced a case of diclofenac-induced tubulointerstitial nephritis and uveitis syndrome. In ruling out infections, Toxoplasma immunoglobulin M was persistently positive, and Toxoplasma immunoglobulin G avidity test indicated a “distant” infection. From these two results, we ruled out recent infection. However, it should be noted that “distant” infection indicated by commercial immunoglobulin G avidity is still a multiplex profile consisting of reinfection, reactivation, and latent infection. Narrowing down the infection profile of Toxoplasma is challenging in some cases. Therefore, careful diagnosis and extended follow-up of such patients are needed.

Dehydroepiandrosterone Effect on Toxoplasma gondii: Molecular Mechanisms Associated to Parasite Death

Toxoplasmosis is a zoonotic disease caused by the apicomplexa protozoan parasite Toxoplasma gondii. This disease is a health burden, mainly in pregnant women and immunocompromised individuals. Dehydroepiandrosterone (DHEA) has proved to be an important molecule that could drive resistance against a variety of infections, including intracellular parasites such as Plasmodium falciparum and Trypanozoma cruzi, among others. However, to date, the role of DHEA on T. gondii has not been explored. Here, we demonstrated for the first time the toxoplasmicidal effect of DHEA on extracellular tachyzoites. Ultrastructural analysis of treated parasites showed that DHEA alters the cytoskeleton structures, leading to the loss of the organelle structure and organization as well as the loss of the cellular shape. In vitro treatment with DHEA reduces the viability of extracellular tachyzoites and the passive invasion process. Two-dimensional (2D) SDS-PAGE analysis revealed that in the presence of the hormone, a progesterone receptor membrane component (PGRMC) with a cytochrome b5 family heme/steroid binding domain-containing protein was expressed, while the expression of proteins that are essential for motility and virulence was highly reduced. Finally, in vivo DHEA treatment induced a reduction of parasitic load in male, but not in female mice.

Acute toxoplasmosis complicated with myopericarditis and possible encephalitis in an immunocompetent patient

We document a case of a 34-year-old man with no medical previous history, presenting with lymphoproliferative syndrome associated to Toxoplasma gondii infection complicated with myopericarditis and possible encephalitis, whose diagnosis was made with lymph node biopsy, cardiac imaging, serology compatible with acute toxoplasmosis and clinical response after treatment.