Detection of toxoplasmosis by serology and nested-PCR in kidney transplant recipients and patients on hemodialysis from Sri Lanka

Toxoplasmosis, the parasitic disease caused by Toxoplasma gondii (T.gondii) affects approximately one-third of the global population. In immunocompromised patients who had been previously infected with T.gondii, the parasite can reactivate to cause infection. This study aimed to determine the seroprevalence of T.gondii among kidney transplant recipients (KTR) and hemodialysis patients (HD) by enzyme-linked immunosorbent assay (ELISA) and to detect T.gondii Deoxyribonucleic Acid (DNA) by nested-Polymerase Chain Reaction (nPCR). Of the 342 patients (114 KTR and 228 HD), 64 (18.7%) and 123 (36%) showed evidence of acute and past infection, respectively, by ELISA, while two (0.6%) had indeterminate results and 153 (44.7%) were negative. In nPCR, there were 28 (8.2%) positives, of which 6.1% only IgG positives, 1.2% only IgM positives, 0.6% both IgM and IgG positives, and 0.3% were indeterminates. The importance of using a combination of serology and molecular methods to determine toxoplasmosis status before commencing treatment in patients awaiting KTR and undergoing HD is indicated by these results. This is the first study that determined toxoplasmosis seroprevalence and targeted the B1 gene using nPCR method to detect toxoplasmosis among KTR and HD patients in Sri Lanka.