Study of the Prevalence and Patterns of Toxoplasmosis in Domestic Cats in Shiraz City and Evaluation of Preventive Strategies to Reduce Transmission to Humans

Toxoplasmosis is a widespread zoonotic parasitic disease caused by the obligate intracellular protozoan Toxoplasma gondii. Domestic cats (Felis catus), members of the Felidae family, serve as the definitive hosts and play a crucial role in the parasite's life cycle by shedding environmentally resistant oocysts in their feces. During primary infection, a single cat may excrete approximately ۱×۱۰۷ to ۱×۱۰۸ oocysts over a ۷-۱۴ day shedding period. These oocysts can survive in soil, water, and other moist environments for ۱۲-۱۸ months, contributing to long-term environmental contamination and increasing the risk of transmission to humans and other animals. Globally, seroepidemiological studies estimate that about ۳۰-۴۰% of the human population has been exposed to T. gondii. In Iran, the reported seroprevalence among humans ranges between ۳۹% and ۵۵%, reflecting relatively high exposure levels. Infection rates in domestic and stray cats in different regions of the country vary from ۲۰% to ۶۰%, depending on environmental conditions, feeding habits, and management practices. In Shiraz, epidemiological studies conducted between ۲۰۱۸ and ۲۰۲۵ indicate that the prevalence of T. gondii infection among domestic cats ranges from ۲۵% to ۴۵%. Higher infection rates have been reported among free-roaming and stray cats (۵۰-۶۰%), while strictly indoor cats show lower prevalence rates of ۱۰-۲۰%. Key risk factors associated with infection include outdoor access, hunting of intermediate hosts such as rodents and birds, consumption of raw or undercooked meat, and poor litter box hygiene. Environmental surveys in urban parks and residential areas of Shiraz have detected oocyst contamination in ۱۰-۲۵% of soil samples. Preventive measures can significantly reduce transmission. Cleaning litter boxes within ۲۴ hours may reduce oocyst sporulation by over ۹۰%, while public health education on food hygiene and handwashing can lower human exposure by ۲۰-۳۰%. Additionally, stray cat population control programs may decrease environmental contamination by up to ۴۰%.

کلیدواژه ها:

Toxoplasma gondii ، toxoplasmosis ، domestic cats ، prevalence ، zoonotic transmission ، Shiraz ، prevention