The first detection of Toxoplasma gondii DNA in environmental air samples using gelatine filters, real-time PCR and loop-mediated isothermal (LAMP) assays: qualitative and quantitative analysis.

Abstract

Toxoplasma gondii infections are acquired through the ingestion of oocysts present in the environment. However, there is no data about their occurrence in the air or about airborne transmission of these infections. In the present paper, we report on the identification of T. gondii using rapid molecular detection methods, supported by microscopic analysis, in environmental air samples. A total of 71 samples were collected, using gelatine filters, from kitchen gardens, recreational areas and sandpits located in northern and north-eastern Poland. Material recovered from the filters was analysed using real-time PCR and loop-mediated isothermal assays targeting the T. gondii B1 gene. Toxoplasma gondii DNA was found in two samples, as confirmed by both molecular assays. Genotyping at the SAG2 locus showed Toxoplasma SAG2 type I. Moreover, the presence of T. gondii oocysts was confirmed in one of the positive samples with the use of microscopy. The results showed that T. gondii may be present in environmental air samples and that respiratory tract infections may play a role in the high prevalence of toxoplasmosis in humans and animals. To the best of our knowledge, this is the first epidemiological evidence that oro-fecal and foodborne toxoplasmosis may be traceable to an airborne respiratory origin and that this may represent a new, previously unknown transmission route for this disease.