Persistence of Eimeria bovis in soil

Area of Science:

• Veterinary Parasitology
• Environmental Microbiology
• Animal Health

Background:

• Eimeriosis is a global cattle disease caused by Eimeria oocysts on pastures.
• Understanding oocyst persistence in soil is crucial for disease control.
• Limited data exists on Eimeria oocyst survival under natural environmental conditions.

Purpose of the Study:

• To investigate the persistence of Eimeria bovis oocysts in soil under temperate climate conditions.
• To evaluate the influence of season and cattle faeces on oocyst survival.
• To determine the impact of environmental exposure on oocyst viability.

Main Methods:

• Soil samples were artificially contaminated with Eimeria bovis oocysts.
• Samples were incubated outdoors from July 2010 to April 2011, with and without cattle faeces.
• Oocysts were recovered using a flotation method and quantified.
• Positive control samples were analyzed immediately after spiking.

Main Results:

• Oocyst recovery rates varied significantly by season and initial spiking time.
• Summer incubation led to a drastic reduction in oocyst recovery (0.30%).
• Oocysts spiked in October showed higher recovery (2.05% without faeces, 2.64% with faeces).
• Faeces positively influenced oocyst integrity but not overall recovery numbers.
• Most oocysts were below detection limits after the winter period.

Conclusions:

• Seasonal factors, particularly summer, significantly reduce Eimeria oocyst survival in soil.
• Overwintering allows for some oocyst persistence, though numbers decrease.
• Cattle faeces may protect oocyst integrity but do not enhance survival rates.
• Further research is needed to fully elucidate oocyst dynamics in pasture environments.