The definitive host for sexual reproduction are felines.
Male and female gametes fuse into zygotes in the cats digestive tract and later turn into oocysts. During shedding, up to 10 million oocysts can be released from feces per day.
Oocysts can remain in moist soil for several months.
Oocysts become infectious one to five days after excretion and begin sporulation.
Oocysts then travel one of four ways:
1. From contaminated soil back to feline
After infection thick tissue walls form and fill with bradyzoites along the feline intestine and produce oocysts, while other bradyzoites penetrate the lamina propr and begin to multiply as tachyzoites. Tachyzoites disseminate to the extra intestinal tissue through the lymph and blood and can enter almost any type of host cell, multiply until the host cell is filled with parasites and dies. The released tachyzoites enter new host cells are repeat the cycle which can result in microfiche of tissue necrosis. When the host overcomes this phase of infection the parasite can enter a resting stage in which the bradyzoites are isolated in tissue cysts. These cysts contain hundreds of bradyzoites and are commonly formed in the brain, liver, and muscles. These cysts usually cause no host reaction and can remain till the death of the host
2. From contaminated soil to rodent to feline
Pseudocysts that form in the rodents area of the brain that processes signals for cat odor and the area of the brain that processes fear. This leads to increase risk taking, decreased ability to recognize predators in local areas, and increased probability that toxoplasma gondii will return to another feline.
3. From contaminated soil to wild life then to humans
For example, ingestion of infected meat that was not properly cooked.
4. From contaminated soil to humans
Cleaning cat litter box without wearing gloves or not washing hands before ingesting something orally. Also, if an individual comes into contact with something that feline fecal mater has previously come into contact with.
Male and female gametes fuse into zygotes in the cats digestive tract and later turn into oocysts. During shedding, up to 10 million oocysts can be released from feces per day.
Oocysts can remain in moist soil for several months.
Oocysts become infectious one to five days after excretion and begin sporulation.
Oocysts then travel one of four ways:
1. From contaminated soil back to feline
After infection thick tissue walls form and fill with bradyzoites along the feline intestine and produce oocysts, while other bradyzoites penetrate the lamina propr and begin to multiply as tachyzoites. Tachyzoites disseminate to the extra intestinal tissue through the lymph and blood and can enter almost any type of host cell, multiply until the host cell is filled with parasites and dies. The released tachyzoites enter new host cells are repeat the cycle which can result in microfiche of tissue necrosis. When the host overcomes this phase of infection the parasite can enter a resting stage in which the bradyzoites are isolated in tissue cysts. These cysts contain hundreds of bradyzoites and are commonly formed in the brain, liver, and muscles. These cysts usually cause no host reaction and can remain till the death of the host
2. From contaminated soil to rodent to feline
Pseudocysts that form in the rodents area of the brain that processes signals for cat odor and the area of the brain that processes fear. This leads to increase risk taking, decreased ability to recognize predators in local areas, and increased probability that toxoplasma gondii will return to another feline.
3. From contaminated soil to wild life then to humans
For example, ingestion of infected meat that was not properly cooked.
4. From contaminated soil to humans
Cleaning cat litter box without wearing gloves or not washing hands before ingesting something orally. Also, if an individual comes into contact with something that feline fecal mater has previously come into contact with.