Waterborne Toxoplasmosis, Brazil, from Field to Gene

Abstract

Water was the suspected vehicle of Toxoplasma gondii dissemination in a toxoplasmosis outbreak in Brazil. A case-control study and geographic mapping of cases were performed. T. gondii was isolated directly from the implicated water and genotyped as SAG 2 type I.

The role of MHC haplotypes H2d/H2b in mouse resistance/susceptibility to cyst formation is influenced by the lineage of infective Toxoplasma gondii strain

“…Importantly, we and others were unable to iso-late the avirulent Type II clonotype T. gondii strains in Brazilian territory, where approximately 80% of all isolated strains were virulent (Dubey et al 2002, Ferreira Ade et al 2004, 2006. However, most of the immunological studies concerning T. gondii infections have been performed with the ME49, a Type II strain.…”

“…Possibly one-third of the world's human population is infected with T. gondii (Dubey 1998, Tenter et al 2000. Infection with the parasite occurs via three main routes: con-86 MARIANNE G. RESENDE et al genitally by transplacental transmission of tachyzoites; ingestion of food or water contaminated with oocysts shed in feces of infected cats (Bahia-Oliveira et al 2003, de Moura et al 2006; or by ingestion of raw or undercooked meat containing tissue cysts (Dubey 1996). Infection is asymptomatic in most individuals, whereas severe pathology and lethality due to toxoplasmosis is a common finding in congenitally infected or immunodeficient patients (Desmonts and Couvreur 1974).…”

“…We have recently reported a non-clonal distribution of natural recombinant Type I/III strains, in different geographic areas of Brazil, where acquired ocular toxoplasmosis (up to 20% of the infected population) is commonly found among patients with chronic toxoplasmosis (Glasner et al 1992, Dubey et al 2002, Fux et al 2003, Ferreira Ade et al 2004, 2006, Portela et al 2004). Importantly, we and others were unable to iso-late the avirulent Type II clonotype T. gondii strains in Brazilian territory, where approximately 80% of all isolated strains were virulent (Dubey et al 2002, Ferreira Ade et al 2004, 2006.…”

Detection of Toxoplasma gondii oocysts in water: proposition of a strategy and evaluation in Champagne-Ardenne Region, France

“…The presence of Toxoplasma DNA in three PDW samples is more surprising, since none of those samples were positive by bioassay. The bioassay is the reference test for Toxoplasma isolation since it is positive in the presence of viable parasites and can be used for genotyping (De Moura et al 2006), but this method is time and cost consuming. In addition, the bioassay is less sensitive for the detection of Toxoplasma in environmental samples, as demonstrated by Isaac-Renton et al (1998).…”

“…Likewise, a large toxoplasmosis outbreak in 2000 was associated with the consumption of contaminated water from a municipal reservoir, which was vulnerable to infiltration due to its precarious state of conservation. Interestingly, water collected from the suspected reservoir was filtered and multiple bioassays were performed in cats, chickens and pigs fed with the membrane filters, leading to parasite isolation and genotyping (De Moura et al 2006). The last outbreak was the only one in which detection of T. gondii in the implicated water source was possible.…”