Implementation and analysis of Babesia immunoassay testing

Abstract

Lifelong withdrawal from the donor population of those who have been diagnosed with babesiosis must be used for transmission prevention. The aim of the study was a detection of Babesia antibodies level with the usage of experimental Babesia divergens whole-cell slide antigen and commercial B. microti immunofluorescence assay substrate slide (Fuller Laboratories, USA). Methods. Experimental B. divergens whole-cell slide antigen in addition to commercial B. microti IFA substrate slide was used to create a diagnostic kit for serum Babesia antibodies level detecting, as well as for a babesiosis serodiagnosis clinical trial of different origins blood samples (patients with Lyme disease, rheumatoid arthritis and toxoplasmosis; human blood donors; cattle). Results. Antibodies to B. divergens (5.4%) and B. microti (2.3%) were detected with higher (p <0.05) frequency at Lyme disease patients (16.7%) than at blood donors (1.7%). Diagnostically significant IgG titres (= 1:128) were found in 13.3% of blood samples from Lyme disease patients and 1.7% from blood donors. Specific IgM were also found in 13.3% blood samples from Lyme disease patients. Among blood samples from Lyme disease patients, in which diagnostically significant titres of Babesia antibodies were detected (16.7%), 60% of them were represented by IgG and IgM (rA= 0.63), and in 40% only one of them reached diagnostically significant titre. Conclusions. Advantages of babesiosis IFA diagnostics are combined with its significant disadvantages (principle of evaluation, low sensitivity in the initial period of the disease, probability of false positives, absence of validated test systems and research protocols for B. divergens and B. divergens-like species).