Additional testing is required to resolve the discordant results.Ī 4 fold change in antibody titer or the presence of Dengue-specific IgM in CSF confirms a recent infection. There is a high probability of non-infection.Īn equivocal result indicates that the presence or absence of antibodies to Trypanosoma cruzi could not be established with either assay.Īn inconclusive result indicates that results between the two assays did not agree. All specimens with presumptive positive, equivocal, and inconclusive results will be forwarded to the Centers for Disease Control and Prevention (CDC) for confirmatory testing.Ī presumptive positive result indicates that antibodies to Trypanosoma cruzi were detected for both assays.Ī negative result indicates that antibodies to Trypanosoma cruzi were not detected for both assays. Results from both assays are considered when determining the final result interpretation. The most convincing evidence of recent infection is a 4 fold rise in titer between an acute and convalescent serum.Īll specimens submitted for Chagas IgG serologic screening will be tested using two different enzyme immunoassays, both designed to detect antibodies to Trypanosoma cruzi, the causative agent of Chagas disease.

You can contact commercial laboratories for Toxoplasma and Bartonella antibody testing, if needed.Ī single titer >= 1:160 is evidence of a prior infection, but does not confirm that it was recent. These sites may also not be accessible to people with disabilities.Įffective immediately, Toxoplasma and Bartonella IgG Antibody tests will no longer be offered at the DSHS Laboratory due to unavailability of reagents. Note: External links to other sites are intended to be informational and do not have the endorsement of the Texas Department of State Health Services. Health Care Information Collection (THCIC).National Electronic Disease Surveillance System (NEDSS).Emergency Medical Services (EMS) Licensure.Asbestos Hazard Emergency Response Act (AHERA).Food Manufacturers, Wholesalers, and Warehouses.Resources for Cancer Patients, Caregivers and Families.Cancer Resources for Health Professionals.Texas Comprehensive Cancer Control Program.Library and Information Science Program.Research, Funding, & Educational Resources.Center for Health Emergency Preparedness & Response.Thus, Western blotting is helpful in identifying false-positive ELISA results for Lyme disease. It is concluded that (1) positive results from both the WB and ELISA assays provide strong diagnostic support for Lyme disease and (2) a positive ELISA test, particularly if at a low titer and without a positive WB test, is associated with a lack of clinical features of Lyme disease. (5) History of tick exposure and degree of fever were not significantly different among the three serologic groups, and thus they were not diagnostically helpful. (4) A definite response to antibiotics occurred in 75% of patients wherein both ELISA and WB were positive but in only 11% of cases with a positive ELISA but a negative WB. (3) Ninety-one percent of group 2 had a rheumatic or inflammatory condition other than Lyme disease. (2) All patients with erythema chronicum migrans had both positive WB and ELISA tests. Findings included the following: (1) Patients with a strong clinical history of Lyme disease were usually positive by both WB and ELISA (group 1). The study population was divided into three groups: group 1 (positive ELISA, positive WB), group 2 (positive ELISA, negative WB), and group 3 (negative ELISA, negative WB). The clinical data from these patients were then analyzed. Of 650 consecutive sera analyzed by ELISA in a laboratory within a 1-year period, 77 were subsequently tested by WB. Patients with discordant ELISA and Western blot (WB) assay results for Borrelia burgdorferi were studied to determine whether there was sufficient clinical evidence to support a diagnosis of Lyme disease. Often, for families and physicians, the clinical dilemma is whether fatigue, arthritis/arthralgias, a positive enzyme-linked immunosorbent assay (ELISA), and tick exposure, but no evidence of erythema chronicum migrans, are sufficient to diagnose and treat Lyme disease. Without evidence of erythema chronicum migrans, diagnostic confirmation of Lyme disease may be difficult, particularly if there are conflicting laboratory results.

Positive elisa negative western blot