coccidiose

Coccidiose, or coccidiosis, is a parasitic disease caused by protozoan parasites of the subclass Coccidia. It affects a wide range of animals, with poultry and livestock being particularly impacted, and can also occur in humans, where it is usually associated with intestinal infection by different Isospora, Cyclospora, Cryptosporidium or Eimeria species. In animals, the disease is most economically significant in poultry, caused primarily by Eimeria species.

The infection is transmitted via oocysts shed in feces. These oocysts sporulate in the environment and become infective after a period of time under suitable moisture and temperature. Ingested sporulated oocysts release sporozoites that invade intestinal cells and undergo asexual and sexual stages, producing new oocysts that are shed in feces, continuing the cycle. The severity depends on the parasite species, host immune status, and environmental conditions.

Clinical signs vary by host and species. In poultry, coccidiosis causes intestinal damage, diarrhea (often with blood), poor weight gain and reduced feed efficiency. In cattle and other livestock, symptoms include diarrhea and dehydration. In humans, infection can range from asymptomatic to mild gastroenteritis; certain species such as Cyclospora and Isospora belli can cause prolonged diarrhea, especially in immunocompromised individuals. Diagnosis relies on detection of oocysts in feces by microscopy with appropriate staining, supplemented by molecular tests in some cases.

Treatment and prevention are species-specific. In animals, anticoccidials (for example, amprolium, ionophores, or toltrazuril) and good husbandry practices help control outbreaks. In humans, therapy may include nitazoxanide for some species or trimethoprim-sulfamethoxazole for others, with attention to immune status. Prevention emphasizes sanitation, clean water, proper litter management in farms, and vaccination where available.