Toxoplasmosis

Abstract

Toxoplasma gondii is a protozoan parasite that infects up to a third of the world's population. Infection is mainly acquired by ingestion of food or water that is contaminated with oocysts shed by cats or by eating undercooked or raw meat containing tissue cysts. Primary infection is usually subclinical but in some patients cervical lymphadenopathy or ocular disease can be present. Infection acquired during pregnancy may cause severe damage to the fetus. In immunocompromised patients, reactivation of latent disease can cause life-threatening encephalitis. Diagnosis of toxoplasmosis can be established by direct detection of the parasite or by serological techniques. The most commonly used therapeutic regimen, and probably the most effective, is the combination of pyrimethamine with sulfadiazine and folinic acid. This Seminar provides an overview and update on management of patients with acute infection, pregnant women who acquire infection during gestation, fetuses or infants who are congenitally infected, those with ocular disease, and immunocompromised individuals. Controversy about the effectiveness of primary and secondary prevention in pregnant women is discussed. Important topics of current and future research are presented.

First report of seroprevalence of <i>Toxoplasma gondii</i> infection in sheep in Pomerania, northern Poland

“…The parasite has a worldwide distribution and is mainly transmitted by food contaminated by oocysts excreted in the faeces of infected cat, by undercooked or raw meat (mainly pork and lamb) containing tissue cysts, or unpasteurized milk of infected animals, and transplacentally [2]. Although the invasion is mostly asymptomatic and selflimiting in immunocompetent individuals, it may lead to a life threatening disease in humans with impaired immune response or immune system immaturity.…”

Partial depletion of CD4+CD25+Foxp3+ T regulatory cells significantly increases morbidity during acute phase Toxoplasma gondii infection in resistant BALB/c mice

“…In humans, the two groups at high risk are foetuses due to their immature immune system and immunocompromised individuals [1]. A primo infection during pregnancy does not always result in congenital infection [2] and clinical manifestations during acute infection vary [1]. This variability, to a great extent, is governed by the immune response of the host, although differences in inoculum size, and virulence of the infecting strain are also important contributory factors [3].…”

Congenital toxoplasmosis: candidate host immune genes relevant for vertical transmission and pathogenesis

“…1 Transplacental passage of the parasite causes congenital toxoplasmosis. Transmission frequency and severity of disease vary with gestation time: during the first weeks, vertical transmission is of low rate, although if it occurs, it causes major damage to the embryo.…”