Simultaneous detection of serum immunoglobulin G antibodies to Cryptosporidium parvum by multiplex microbead immunoassay using 3 recognized specific recombinant C. parvum antigens

Cryptosporidiosis is a significant diarrheal disease in both humans and other mammals worldwide. In the present study, we established and validated a multiplex microbead immunoassay (MIA) for surveillance of Cryptosporidium parvum infections. In the multiplex MIA, 3 specific recombinant proteins, CP23, SA35, and SA40, were used as the capture antigens simultaneously. The antibody directed against CP23 is an index of historic infection, and those against SA35 and SA40 are indices of recent infection. The multiplex MIA yielded essentially identical results with that of monoplex MIA using these 3 recombinant proteins, and the reproducibility of the multiplex MIA results was high when standardized with a calibration curve. With multiplex MIA, we detected that the pediatric population showed a higher percentage of recent infections (seropositive rates of antibodies directed against CP23, SA35, and SA40 were 6.28%, 23.19%, and 22.71%, respectively, n = 207), whereas the adult population showed a higher percentage of historic infections (seropositive rates of antibodies directed against CP23, SA35, and SA40 were 24.40%, 11.48%, and 16.75%, respectively, n = 209).