Background: During the past 10 years in our clinical immunology laboratory, we have observed that some patients with high titers of antibodies against the Herpes family of viruses also exhibit elevation in antibodies against Borrelia burgdorferi antigens. Furthermore, when sera from patients with high IgG antibody levels against B. burgdorferi and Epstein-Barr virus were tested for food-specific antibodies, the degree of immune reactivity to food antigens was much higher in patients who were seropositive for B. burgdorferi and EBV antigens than in those who were seronegative. We purchased monoclonal and affinity-purified polyclonal antibodies against B. burgdorferi, Herpes family viruses and other infectious agents, and reacted them with 180 different food antigens so we could examine the degree of cross-reactivity between infectious agents and various food antigens. Methods: Using ELISA methodology, we applied monoclonal and affinity-purified polyclonal antibodies against Epstein-Barr virus, cytomegalovirus, measles, rubella, herpes simplex type 1, Varicella zoster, Chlamydia pneumoniae, streptokinase, Yersinia enterocolitica and Borrelia burgdorferi, to 180 different food antigens in order to explain some baffling test results detected during lab testing. Results: While some of these antibodies did not react to any of the tested food antigens, B. burgdorferi antibody reacted with 39 foods, EBV-VCA antibody with 20, EBNA-1 antibody with 10, EBV-EA antibody with 20, rotavirus antibody with 11, and measles antibody with 4 out of 180 food antigens. We demonstrated that these antibodyantigen reactions are specific, since only specific antigens and not non-specific antigens inhibited these immune reactivities. Conclusions: Results indicate that the presence of some of the antibodies against infectious agents detected in human serum can result in false-positivity in serologic tests for food antigens used in the diagnosis of food adverse reactions. These results may explain antibody detection in the sera of many individuals against various food antigens that they have never actually eaten.