Contaminated water confirmed as source of infection by bioassay in an outbreak of toxoplasmosis in South Brazil

Abstract

Toxoplasma gondii-a protozoan belonging to the subphylum Apicomplexa (Adl et al., 2012) and family Sarcocystidae-is the causal agent of toxoplasmosis, an important and widespread zoonotic disease. The protozoan life cycle involves domestic and wild felids as definitive hosts and a number of mammals, including humans, as intermediate hosts. Modes of T. gondii transmission to human include (a) ingestion of sporulated oocysts present in contaminated water or food; (b) ingestion of bradyzoite-containing cysts present

Contamination of Soil, Water, Fresh Produce, and Bivalve Mollusks with Toxoplasma gondii Oocysts: A Systematic Review

“…Water was the environmental matrix most extensively studied worldwide with 25 out of 40 articles reporting T. gondii -positive samples in Brazil ( n = 6), Colombia ( n = 2), Egypt ( n = 1), France ( n = 2), French Guiana (France) ( n = 1), Germany ( n = 1), Greece and Bulgaria ( n = 1), Iran ( n = 1), Mexico ( n = 1), Pakistan ( n = 1), Poland ( n = 3), Russia and Bulgaria ( n = 1), Scotland ( n = 1), Serbia ( n = 1), Spain ( n = 1), and Turkey ( n = 1). Overall, detection rates ranged from 5% (1/20) in Greece [ 50 ] to 100% (8/8) in Brazil [ 51 ], and most studies reported a detection rate below 20% ( Table 2 and Figure 2 ; Supplementary Table S3 ).…”

“…Indeed, only 13 of the selected articles studied the association between oocyst detection in environmental matrices with human T. gondii infection and toxoplasmosis (outbreaks, endemic, or sporadic cases), most of them from North and South America. Five of these studies focused on soil [ 56 , 60 , 70 , 77 , 80 ], with three of them reporting positive samples; 10 were in water [ 51 , 60 , 70 , 87 , 88 , 89 , 91 , 92 , 104 , 105 ], with eight reporting positive samples; and three were on fresh produce [ 60 , 88 , 92 ], with one reporting positive samples and the other reporting negative samples, but suggesting that the occurrence of toxoplasmosis was connected with vegetable consumption in a restaurant [ 60 ] ( Table 1 , Table 2 , Table 3 and Table 4 ).…”

“…The public health importance of different contaminated water sources is determined by their uses. In relation to this, one article reported 9.0% (9/100) recreational water samples to be oocyst positive [ 78 ], while the detection rates were between 16.7% (9/54) [ 95 ] and 50.0% (1/2) [ 88 ] in irrigation/washing water, and 2.3% (1/44) [ 97 ] and 100% (8/8) [ 51 ] in potable water. The origin of these samples was not specified in all cases; the recreational water corresponded to lakes and pools, the irrigation/washing water was from a river, and in one study, the potable water corresponded to water kept in tanks/towers from houses, in fountains, and from the water and sewage company.…”

“…The origin of these samples was not specified in all cases; the recreational water corresponded to lakes and pools, the irrigation/washing water was from a river, and in one study, the potable water corresponded to water kept in tanks/towers from houses, in fountains, and from the water and sewage company. One study with 100% of positive potable water samples was linked to a human toxoplasmosis outbreak in Santa Maria, Brazil, which was one of the largest studies worldwide with around 902 confirmed cases [ 51 ] and one of the few that used piglet bioassay for parasite detection; thus, oocysts infectivity was confirmed.…”

Identification of Oocyst-Driven Toxoplasma gondii Infections in Humans and Animals through Stage-Specific Serology—Current Status and Future Perspectives

“…There are few documented T. gondii outbreaks in humans, and the acute infection can present with vague, unspecific clinical signs that can be overlooked [5]. Waterborne outbreaks have been easier to identify given the large number of people affected [33,40,44,45].…”