Eimeria

Parasite210097 - Fig2 - Eimeria spp. ex Moschus berezovskii

Eimeria is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in animals such as poultry, cattle, and smaller ruminants. These parasites are of significant concern in the fields of veterinary medicine and animal husbandry, due to their impact on animal health and the agricultural economy.

Life Cycle

The life cycle of Eimeria species is complex and involves both asexual and sexual phases, which occur within the intestines of the host animal. The cycle begins when an animal ingests oocysts, the infectious form of the parasite, from the environment. Inside the host's intestines, the oocysts undergo sporulation, releasing sporozoites that invade the intestinal cells. This is followed by a series of asexual and sexual reproductive cycles that produce new oocysts, which are then excreted in the feces, contaminating the environment and potentially infecting other hosts.

Species and Hosts

There are numerous species of Eimeria that infect a wide range of hosts. For example, Eimeria tenella, Eimeria maxima, and Eimeria acervulina are well-known for causing coccidiosis in chickens, leading to significant economic losses in the poultry industry. Other species, such as Eimeria bovis and Eimeria zuernii, are known to infect cattle.

Symptoms and Diagnosis

The clinical signs of coccidiosis vary depending on the species of Eimeria involved and the severity of the infection but often include diarrhea, which may be bloody, weight loss, reduced feed intake, and in severe cases, death. Diagnosis is typically made by microscopic examination of feces to identify and count oocysts.

Control and Prevention

Control and prevention of coccidiosis are primarily achieved through hygiene and management practices that reduce oocyst exposure, the use of coccidiostatic drugs in feed, and vaccination. Vaccines against coccidiosis are available for some species, such as chickens, and have been shown to be an effective method of control.

Economic Impact

The economic impact of Eimeria infections, particularly in the poultry and cattle industries, is significant. Losses result from reduced productivity, increased mortality, and the costs associated with prevention and treatment of the disease.