Diseases of Digestive Sytem

Life cycle of Emeria species

Coccidiosis | Life Cycle

Coccidiosis Life cycle

Coccidiosis defined as single cell protozoan disease that caused by Emeria species under the family of apicomplexa. Most common characteristics of Emeria species are single cells & intracellular parasites. Sometimes its  uncontrollable due to their repeated life cycle of Emeria species. So it has precious life cycle. . Emeria have complex life cycle which completely multiply into the chicken.

There are seven species of Emeria may exist in worldwide. Some common species are Emeria tanella, Emeria acervulina, maxima, nicartrix, brunetti etc which causing coccidiosis in poultry.

Life cycle of coccidiosis so much important due to identify the lesion in the intestine of poultry. If we know the life cycle of coccidiosis, we can isolates the Emeria species easily due to they specified site of infection in the intestine.

So Life cycle of coccidiosis represent by flow chart

Broadly life
cycle of coccidiosis divided by two cycles- Asexual & Sexual reproduction & both have unique stages

Asexual Reproduction

Life cycle of coccidiosis by Asexual reproduction started from Ocyst from infected host by faeces. There are two types OOcycst involved this process.

  1. Unsporoluted Oocyst

It considered fresh Ocyst which newly come out in the environment from intestine of poultry. Its also called Oocyst. Most common characteristics are covering by thick wall, highly resistant to temperature & disinfactant.

2. Sporoluted Oocyst

A cyst like thick wall round structure contain encysted zygote produced from sporoblast from which sporozoite develop by Emeria protozoan species. The process of formation sporocyst called sporolution. This sporocyst called sporulated ocyst. Sporolated ocyst called infective stages of Emeria species. Meosis cell division is present this process.

Severals factors involved for sporulation like poultry litter condition, temperature, moisture & Oxygen etc. Sporulation take place outside the host.

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Sporulated Oocyst engulfed by normal birds from faeces. Engulfment not depends on ages, any aged poultry intake oocyst from litter in the flock.

Sporulated Ocyst crushed by gizzard ventricles & Release sporoluted ocyst in the intestine in the poultry.


Sporulated Oocyst convert four sporocyst & each contain two sporozoites by the action of chemotripsin & bile salt.

Release million of sporozoites in lumen of inrestine by process of  Excystation in asexual reproduction.

The motile sporozoites into the enterocytes of small intestine then migrate to their respective sites of development

This results sporozoites attachment to host cell receptors by gliding motility. Attachment can initiate continuous reproduce sporozoites.

Then Enter into the epithelial cells of epithelium Or Intraepithelial cells lymphocyts intestine of poultry. the sporozoites develop into Tropozoites by asexual reproduction

Convert Schizont afetr several rounds of asexual reproduction of schizont in the inrestine.This results in many nuclei developing within the schizont by asexual reproduction . Each nucleus develops into a merozoite which initiate sexual reproduction.schizonts rupture, million of merozoites are released intestine.

Schizont either go on to re-infect more enterocytes or develop into either male or female gametes via the process of gametogenesis

Sexual reproduction


Microgametocytes produce microgametes that burst from the infected cells, enter into the cells containing macrogametes, and fertilized them. As a result zygotes comes out from impermeable cyst wall around themself & finally Ocyst are formed.

These gametes fuse to form an oocyst & Ocyst rupture from host cells which is then released in its non-infectious, unsporulated form through the faeces of the host & excrete by faeces in the environmrnt. 

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