Question

Describe the life cycle of Toxoplasma gondii in the nonfeline host and describe its importance to veterinary and human medicine. Also discuss how transmission to humans can be prevented. 


Answer 1

ANSWER :

TOXOPLASMA GONDII :

Toxoplasma gondii is a intracellular parasite having one eukaryote, which causes serious infectious disease named TOXOPLASMOSIS.

LIFE CYCLE OF TOXOPLASMA GONDII IN NONFELINE HOST :

Cats play a important role as host in life cycle of Toxoplasma Gondii. If the cat ingests infected meat of animals having sporulated oocytes, is transmitted to intestines of cat that is called as Tachyzoites. There the developed oocysts shed in the feces of cat, where the cyst wall of the oocyst gets dissolved by an proteolytic enzyme in stomach and small intestine which release Bradyzoites. They slowly multiply in stage and penetrate small intestine epithelial cells for the formation of asexual cycles before sexual cycle formation. When a male and female gamete fertilizes two walls surrounding fertilized zygote form oocyst which is excreted completely as unsporulated stage in feces Each oocyst measure 10-12 cm   and become infectious after 1 to 5 days of excretion, containing 2 sporocysts and each one contains 4 sporozoites. These sporulated oocysts can survive in soil for several months. Within few hours of infection tachyzoites invades to extra intestinal tissues by lumph and blood. Released tachyzoites enter into new host body and gets multiply. In this stage host gets infected and parasite goes into resting stage where bradyzoites are isolated. Formed tissue cysts are present in brain, muscles, liver and cause no host reaction and remain in host. In nonfeline hosts like human beings and mice is similar to cycle with definiyive hosts.

IMPORTANCE OF TOXOPLASMA TO VETERINARY AND HUMAN MEDICINE :

As Toxoplasma gondii shows adverse effects on humans, veterinaries play an important role in educating human population about risk of infection, which will spread from eating of rats, birds, and other animals. If the infection is not controlled on the early stages of attack it leads to serious side effects on health of humans.

HOW TRANSMISSION CAN PREVENTED IN HUMANS?

* Wash fruits and vegetables with water before eating them

* Avoid feeding of house cats in open utensils, separate their food

* Avoid using of utensils or food contaminated with cats feces with direct contact

* Clean the area with disinfectants and wear gloves and mask at the time of cleaning

* Monitoring of pregnant women with careful monitoring prevents spread of infection.