Detection of Toxoplasma gondii in environmental matrices (water, soil, fruits and vegetables)

Toxoplasmosis is a widely distributed protozoan disease caused by Toxoplasma gondii. The infective stages of T. gondii are capable of infecting a variety of vertebrates including humans. Domestic and wild felids are capable of serving as definitive hosts and T. gondii oocysts are excreted in their faeces. Toxoplasmosis is caused by ingesting T. gondii oocysts from contaminated water or foodstuff or by consuming T. gondii tissue cysts from infected hosts. However, the impact of oocysts on toxoplasmosis epidemiology needs to be specified because they are suspected to be associated with T. gondii seroprevalence in some emerging outbreaks of acute toxoplasmosis in humans from soil or water. They are probably responsible for a significant part of infections in animals that could be later consumed by humans. Detection of T. gondii oocysts in environmental samples is great challenge as this coccidian parasite can be responsible for severe infections in humans and animals via ingestion of a single oocyst from contaminated water, soil, fruits or vegetables. The present study was designed to develop methods for the detection of oocysts from water, soil and food. The highest prevalence was reported from water around farms (13%) followed by lakes and pools (9%) and water reservoirs (7%). The lowest rates resulted from drinking water and tubewells (6% each). Overall prevalence of T. gondii contamination was higher in vegetables (5.6 %) than fruits (4 %). The highest prevalence of T. gondii contamination was noted in gardens and backyards of homes and gardens, that is, 20 and 20%, respectively. In these places, cats often defecate and become a source of infection. Then followed by public enclosures where infection was 14.3%. The lowest (13.3%) contamination was noted in homes of urban areas. T. gondii infection in rural areas was the highest (20%) in home back yards followed by homes (16.7%) then public enclosure (14.5%) whereas the lowest (13.3%) at gardens of rural areas.