Summary: The apicomplexan parasite Toxoplasma gondii was discovered a little over 100 years ago, but knowledge of its biological life cycle and its medical importance has grown in the last 40 years. This obligate intracellular parasite was identified early as a pathogen responsible for congenital infection, but its clinical expression and the importance of reactivations of infections in immunocompromised patients were recognized later, in the era of organ transplantation and HIV infection. Recent knowledge of host cell-parasite interactions and of parasite virulence has brought new insights into the comprehension of the pathophysiology of infection. In this review, we focus on epidemiological and diagnostic aspects, putting them in perspective with current knowledge of parasite genotypes. In particular, we provide critical information on diagnostic methods according to the patient's background and discuss the implementation of screening tools for congenital toxoplasmosis according to health policies.

https://hal.archives-ouvertes.fr/hal-00696903/document

Epidemiology of and Diagnostic Strategies for Toxoplasmosis

https://www.clinicalmicrobiologyandinfection.com/article/S1198-743X(14)62509-X/pdf

Toxoplasma gondii: transmission, diagnosis and prevention

Toxoplasma gondii infection in humans and animals in the United States.

Toxoplasmosis snapshots: Global status of Toxoplasma gondii seroprevalence and implications for pregnancy and congenital toxoplasmosis

Toxoplasmosis: a history of clinical observations

Toxoplasma gondii: from animals to humans

http://www.swrcb.ca.gov/rwqcb3/board_info/agendas/2006/feb/item5/docs/molecularandbioassaybaseddetectionoftoxoplasmaoocystuptakebymussels.pdf

Molecular and bioassay-based detection of Toxoplasma gondii oocyst uptake by mussels (Mytilus galloprovincialis)

Phylogenetic analysis based on full-length large subunit ribosomal RNA gene sequence comparison reveals that Neospora caninum is more closely related to Hammondia heydorni than to Toxoplasma gondii

Two methods, centrifugation and flocculation, were evaluated to determine their efficiencies of recovery of Toxoplasma gondii oocysts from contaminated water samples. Demineralized and tap water replicates were inoculated with high numbers of sporulated or unsporulated T. gondii oocysts (1 × 105 and 1 × 104 oocysts). The strain, age, and concentration of the seeded oocysts were recorded. Oocysts were recovered either by centrifugation of the contaminated samples at various g values or by flocculation with two coagulants, Fe2(SO4)3 and Al2(SO4)3. The recovery rates were determined with the final pellets by phase-contrast microscopy. Sporulated oocysts were recovered more effectively by flocculation with Al2(SO4)3 (96.5% ± 21.7%) than by flocculation with Fe2(SO4)3 (93.1% ± 8.1%) or by centrifugation at 2,073 × g (82.5% ± 6.8%). For the unsporulated oocysts, flocculation with Fe2(SO4)3 was more successful (100.3% ± 26.9%) than flocculation with Al2(SO4)3 (90.4% ± 19.1%) or centrifugation at 2,565 × g (97.2% ± 12.5%). The infectivity of the sporulated oocysts recovered by centrifugation was confirmed by seroconversion of all inoculated mice 77 days postinfection. These data suggest that sporulated Toxoplasma oocysts purified by methods commonly used for waterborne pathogens retain their infectivity after mechanical treatment and are able to induce infections in mammals. This is the first step in developing a systematic approach for the detection of Toxoplasma oocysts in water.

Anja R Heckeroth

Papers

Toxoplasma gondii: from animals to humans

Molecular and bioassay-based detection of Toxoplasma gondii oocyst uptake by mussels (Mytilus galloprovincialis)

Phylogenetic analysis based on full-length large subunit ribosomal RNA gene sequence comparison reveals that Neospora caninum is more closely related to Hammondia heydorni than to Toxoplasma gondii

Development and application of different methods for the detection of Toxoplasma gondii in water.

Erratum to “Toxoplasma gondii: from animals to humans” [Int. J. Parasitol. 30 (2000) 1217–1258]