Biological researchers at the University of London’s Royal Veterinary College (RVC) are a step closer to finding a new cost-effective vaccine for the intestinal disease, coccidiosis. The disease, caused by protozoan parasites of the genus Eimeria, affects chickens’ intestines and if not controlled has extremely high mortality rates.

Domestic chickens can be infected by seven species of Eimeria, each colonizing a preferred region of the intestine and causing symptoms of differing severity. In a decade-long collaborative research project, biologists at the RVC have helped produce full genome sequences of all seven of these species.

This is major breakthrough for the poultry production industry in its fight against coccidiosis, which puts the global economic cost of infection at around GBP1.8 billion (US$3.06 billion). This is mainly due to production losses combined with costs of prevention and treatment.

The research is being published in the academic journal Genome Research and is funded by the Biotechnology and Biological Sciences Research Council.

Coccidiosis affects all livestock but is particularly hurtful to poultry because of the high density that chickens can be housed in during the production process. Eimeria species that cause coccidiosis have a direct fecal-oral life cycle that is ideal for spreading rapidly through susceptible hosts when housed in close quarters.

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These parasites are also particularly devastating because they survive for long periods in environments such as feces and litter. This means most chicken flocks in the world are exposed, with many inevitably becoming infected. Drugs are commonly used to control the parasites, but resistance evolves rapidly and there is a continuing need to develop new, effective control of disease. 

Professor Fiona Tomley, RVC head of pathology and pathogen biology, and Dr. Damer Blacke, RVC senior lecturer in parasitology, are co-authors of the research, which is being published in the academic journal, Genome Research.

“Understanding the genetic code of Eimeria parasites will help in the race to develop new therapies for coccidiosis,” said Tomley. “With poultry production expansion predicted to continue for at least the next 30 years, and with Africa and Asia accounting for most of this growth, developing a new generation of cheap effective vaccines against coccidiosis will be a major contribution to global food security.”