RÉSUMÉ
We present a set of data on human and chicken Toxoplasma gondii seroprevalence that was investigated and analysed in light of groundwater vulnerability information in an area endemic for waterborne toxoplasmosis in Brazil. Hydrogeological assessment was undertaken to select sites for water collection from wells for T. gondii oocyst testing and for collecting blood from free-range chickens and humans for anti-T. gondii serologic testing. Serologic testing of human specimens was done using conventional commercial tests and a sporozoite-specific embryogenesis-related protein (TgERP), which is able to differentiate whether infection resulted from tissue cysts or oocysts. Water specimens were negative for the presence of viable T. gondii oocysts. However, seroprevalence in free-range chickens was significantly associated with vulnerability of groundwater to surface contamination (p < 0.0001; odds ratio: 4.73, 95% confidence interval: 2.18-10.2). Surprisingly, a high prevalence of antibodies against TgERP was detected in human specimens, suggesting the possibility of a continuous contamination of drinking water with T. gondii oocysts in this endemic setting. These findings and the new proposed approach to investigate and analyse endemic toxoplasmosis in light of groundwater vulnerability information associated with prevalence in humans estimated by oocyst antigens recognition have implications for the potential role of hydrogeological assessment in researching waterborne toxoplasmosis at a global scale.
Sujet(s)
Poulets/parasitologie , Eau douce/parasitologie , Oocystes , Toxoplasma/immunologie , Toxoplasmose/épidémiologie , Maladies hydriques/épidémiologie , Adolescent , Adulte , Sujet âgé , Sujet âgé de 80 ans ou plus , Animaux , Anticorps antiprotozoaires/sang , Antigènes de protozoaire/analyse , Brésil/épidémiologie , Enfant , Test ELISA , Femelle , Humains , Mâle , Adulte d'âge moyen , Protéines de protozoaire/analyse , Études séroépidémiologiques , Toxoplasma/isolement et purification , Toxoplasmose/diagnostic , Toxoplasmose/transmission , Toxoplasmose animale/diagnostic , Toxoplasmose animale/épidémiologie , Maladies hydriques/diagnostic , Maladies hydriques/transmission , Jeune adulteRÉSUMÉ
We present a set of data on human and chicken Toxoplasma gondiiseroprevalence that was investigated and analysed in light of groundwater vulnerability information in an area endemic for waterborne toxoplasmosis in Brazil. Hydrogeological assessment was undertaken to select sites for water collection from wells for T. gondiioocyst testing and for collecting blood from free-range chickens and humans for anti-T. gondiiserologic testing. Serologic testing of human specimens was done using conventional commercial tests and a sporozoite-specific embryogenesis-related protein (TgERP), which is able to differentiate whether infection resulted from tissue cysts or oocysts. Water specimens were negative for the presence of viable T. gondiioocysts. However, seroprevalence in free-range chickens was significantly associated with vulnerability of groundwater to surface contamination (p < 0.0001; odds ratio: 4.73, 95% confidence interval: 2.18-10.2). Surprisingly, a high prevalence of antibodies against TgERP was detected in human specimens, suggesting the possibility of a continuous contamination of drinking water with T. gondiioocysts in this endemic setting. These findings and the new proposed approach to investigate and analyse endemic toxoplasmosis in light of groundwater vulnerability information associated with prevalence in humans estimated by oocyst antigens recognition have implications for the potential role of hydrogeological assessment in researching waterborne toxoplasmosis at a global scale.
Sujet(s)
Adolescent , Adulte , Sujet âgé , Sujet âgé de 80 ans ou plus , Animaux , Enfant , Femelle , Humains , Mâle , Adulte d'âge moyen , Jeune adulte , Poulets/parasitologie , Eau douce/parasitologie , Oocystes , Toxoplasma/immunologie , Toxoplasmose/épidémiologie , Maladies hydriques/épidémiologie , Anticorps antiprotozoaires/sang , Antigènes de protozoaire/analyse , Brésil/épidémiologie , Test ELISA , Protéines de protozoaire/analyse , Études séroépidémiologiques , Toxoplasma/isolement et purification , Toxoplasmose animale/diagnostic , Toxoplasmose animale/épidémiologie , Toxoplasmose/diagnostic , Toxoplasmose/transmission , Maladies hydriques/diagnostic , Maladies hydriques/transmissionRÉSUMÉ
American mink (Neovison vison) is a widely distributed invasive species in southern Chile. Thirty four feral minks were trapped at two distinct sites (rural and peri-urban), diet analyzed and Toxoplasma gondii exposure compared using PCR and specific antibodies. Serum samples were evaluated using a commercial latex agglutination test where a titer ≥ 1:32 was considered positive. Of 30 mink analyzed, 21 (70%) were positive to T. gondii antibodies, with titers ranging from 1:32 to 1:2048. As expected, adult mink showed higher seroprevalence of exposure to T. gondii (18/21) than young mink (3/9) (P=0.008). There was not statistically significant difference between sex groups (P=0.687). Differences in seroprevalence were observed between the two sample sites with a higher proportion of positive individuals in the peri-urban area, and therefore, closer to human settlements (35.7% vs. 100%, P=0.0001). Individuals positive to T. gondii using PCR and/or serology showed similar differences by site with higher infected individuals in peri-urban areas (58.8% vs. 100%, P=0.007). Diet of American mink based in fecal composition analyses was mainly based on crustaceans (frequency of occurrence: crustaceans=100%, birds and rodents<7%), suggesting that the high observed prevalence of T. gondii infection might be more associated with its aquatic behavior (e.g. ingestion of oocysts in contaminated fresh water) than with their trophic behavior (e.g. preying over species that can have T. gondii cysts in their tissues). As an invasive species potentially subject to routine culling to maintain population sizes under control, minks could be used as a sentinel species to monitor pathogens of public and wildlife health importance, such as T. gondii, in aquatic environments.
Sujet(s)
Visons , Toxoplasmose animale/parasitologie , Animaux , Chili , Démographie , Fèces/parasitologie , Femelle , Espèce introduite , Mâle , Études séroépidémiologiques , Toxoplasmose animale/épidémiologieRÉSUMÉ
Infection source can determine cost-effective public health interventions. To quantify risk of acquiring Toxoplasma gondii from environmental sources versus from meat, we examined serum from pregnant women in Chile. Because 43% had oocyst-specific antibodies, we conclude that contaminated meat remains the primary source of infection but that environmental sources also pose substantial risk.