Toxoplasma gondii infection in humans is mainly due to consumption of infected raw or undercooked meat and meat products or to accidental ingestion of sporulated oocysts. Nonetheless, human infection could also be caused by the ingestion of unpasteurized milk and milk products. Since ewes’ milk is widely used in Italy to produce raw-milk cheese which is locally consumed and world-wide exported, a better understanding of the relevance of the infection rate in sheep herds and the implication as public health threat are needed. Aim of the present paper was to evaluate the prevalence of T. gondii in sheep herds located in the infected flocks. For this tool thirty-six ewe herds located in the Perugia Province were investigated for the presence of Toxoplasma gondii antibodies and DNA in bulk milk. Samples were collected at 3 week interval for three times for each flock and analyzed by immunofluorescence antibody test (IFAT) and loop-mediated isothermal amplification (LAMP) methods, for the detection of T. gondii antibodies (IgG) and target DNA respectively. Flocks were considered positive to T. gondii if at least one bulk milk sample collected tested positive at one of the analytic methods. Twenty-nine flocks were positive with a prevalence of 80.56% but a slight concordance was registered between the two methods considered, in fact the K -value obtained by the agreement analysis between IFAT and LAMP was 0.125. Furthermore, only 30% of the flocks were positive in all three bulk milk samples collected through antibodies, and none by DNA detection. The use of only one method and only one sample, when bulk milk is considered for T. gondii screening in sheep flocks, must therefore be strongly discouraged. Further studies are needed to better define control procedure to reduce the prevalence of positive flocks in the investigated areas as well as to better understand the significance for human health of T. gondii in ewe milk and products.
Screening of Toxoplasma gondii positive sheep flocks in Perugia Province (Umbria Region,Central Italy) using bulk milk analyses
Veronesi Fabrizia;Zanet Stefania;SEBASTIANI, VALENTINA;Branciari Raffaella;Valiani Andrea;Ranucci David
2018
Abstract
Toxoplasma gondii infection in humans is mainly due to consumption of infected raw or undercooked meat and meat products or to accidental ingestion of sporulated oocysts. Nonetheless, human infection could also be caused by the ingestion of unpasteurized milk and milk products. Since ewes’ milk is widely used in Italy to produce raw-milk cheese which is locally consumed and world-wide exported, a better understanding of the relevance of the infection rate in sheep herds and the implication as public health threat are needed. Aim of the present paper was to evaluate the prevalence of T. gondii in sheep herds located in the infected flocks. For this tool thirty-six ewe herds located in the Perugia Province were investigated for the presence of Toxoplasma gondii antibodies and DNA in bulk milk. Samples were collected at 3 week interval for three times for each flock and analyzed by immunofluorescence antibody test (IFAT) and loop-mediated isothermal amplification (LAMP) methods, for the detection of T. gondii antibodies (IgG) and target DNA respectively. Flocks were considered positive to T. gondii if at least one bulk milk sample collected tested positive at one of the analytic methods. Twenty-nine flocks were positive with a prevalence of 80.56% but a slight concordance was registered between the two methods considered, in fact the K -value obtained by the agreement analysis between IFAT and LAMP was 0.125. Furthermore, only 30% of the flocks were positive in all three bulk milk samples collected through antibodies, and none by DNA detection. The use of only one method and only one sample, when bulk milk is considered for T. gondii screening in sheep flocks, must therefore be strongly discouraged. Further studies are needed to better define control procedure to reduce the prevalence of positive flocks in the investigated areas as well as to better understand the significance for human health of T. gondii in ewe milk and products.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
