Dispersion of Echinococcus granulosus eggs from infected dogs under natural conditions in Patagonia, Argentina

Abstract

Cystic echinococcosis caused by Echinococcus granulosus is a major zoonosis of public health significance in the Patagonian region of Argentina. This investigation sought to test the hypothesis that the persistence and dispersion of the parasite eggs can be explained by physical and meteorological parameters along with final host infection and behaviour. This observational study was carried out over a five-year period within an enclosure where two dogs harbouring a worm burden ranging from 100 to 1000 mature adult E. granulosus, as well as two uninfected dogs, had previously been kept for six months. Environmental canine faeces, topsoil, pond water, and sediment samples were examined to control for the presence of eggs and coproantigens of the parasite using microscope-based techniques and copro-ELISA plus copro-Western Blot tests. The parasite eggs were detected up to 41 months later in faeces from infected dogs, soil and sediment, and coproantigen tests remained positive for up to 70 months in faeces. Overall, parasite eggs were found within a maximum distance of 115 m from the contaminated dog faeces deposition site. Our findings indicate that under Patagonian environmental conditions, egg persistence and dispersion seem to be related to the worm burden and habits of the infected dog, to prevailing wind direction and to the existence of low bushes as well as natural bodies of water. The present study is the first to provide direct evidence of interaction between bioclimatic conditions and E. granulosus egg dispersion under Patagonian field conditions. https://www.cambridge.org/core/terms. https://doi.

Epidemiology and spatial distribution of Echinococcus granulosus in sheep and goats slaughtered in a hyperendemic European Mediterranean area

“…These values are higher than those reported in sheep and goats in other countries of the Mediterranean area, respectively: 30.2% and 7.6% in Greece [ 23 ]; 16.4% and 2.9% in Tunisia [ 24 ]; 6.9% and 1.6% in Algeria [ 25 ]; < 0.1% for both in Spain [ 26 ]; and < 0.002% for sheep and absence of infected goats in the last national census conducted in France [ 27 ]. The variation in the prevalence of CE in different parts of the world may be associated not only with environmental factors such as cool temperatures, high rainfall and shade, which increase the probability of egg survival in the environment and favor the transmission of CE in livestock, but also with control measures and breeding systems, number of dogs in each location, and education level and economic status of the population [ 28 ]. In the Mediterranean area, CE is predominant particularly in countries with large numbers of grazing sheep.…”

Spatial Distribution and Epidemiology of Echinococcus Granulosus Infection in Sheep and Goats Slaughtered in a Hyperendemic European Mediterranean Area

“…in Algeria [23]; < 0.1% for both in Spain [24]; and < 0.002% and absence of infected goats in the last national census conducted in France [25]. The variation in the prevalence of CE in different parts of the world may be associated not only with environmental factors such as cool temperatures, high rainfall and shade that increase the probability of egg survival in the environment and favor the transmission of CE in livestock, but also with control measures and breeding systems, numbers of dogs in each location, education level and economic status of the population [26]. In the Mediterranean area, echinococcosis is predominant particularly in countries with large number of grazing sheep.…”

Human and animal cystic echinococcosis in Tataouine governorate: hypoendemic area in a hyperendemic country, myth or reality?

“…Tunisia is a country with a past and current history of pastoral husbandry, especially in the southern regions where traditional livestock breeding systems are based on the use of large rangelands [20]. The differences in prevalence observed in the present study might have been influenced by the level of environmental contamination by E. granulosus s.s. eggs and the climatic conditions (low rainfall and high temperature in summer) that reduce the viability of eggs [40], but also by livestock age at slaughter. It is known that the E. granulosus s.l.…”