2020; 2(1): 8-16PublishedOnline:01/10/2020 (https://journals.unza.zm/index.php?journal=medicine) DOI: 10.21617/jprm2020.213ISSN: 2415-038X (Print)Received: 14August2020Accepted: 16August 2020Published: 1October2020RESEARCH ARTICLEOpen AccessComparison of Serologic Diagnosis of Taeniosis and Cysticercosis in Field Samples from Eastern Zambia

Background:Neurocysticercosis is a leading cause of epilepsy in Taenia soliumendemic regions of the world accounting for about 30% of all epileptic cases. The main aim of this study was to do aComparison of Serologic Diagnosis of Taeniosis and Cysticercosis in Field Samples from Eastern Zambia.Methods: Retrospectively collectedSamples through community-based cross sectional and longitudinal studies which looked at the prevalence and incidence of human T. solium infections, respectively, and described in earlier reports were selected for this laboratory based study. Samples, with coproantigen ELISA and serum antigen ELISA which the results were known were randomly selected for this study.Results: A total of 886 serum samples were analyzed. The rT24 /rES33 EITB detected a taeniosis and cysticercosis prevalence of 5.9% and 9.5%, respectively. On performance the Kappa statistics revealed a fair agreement of rT4/rES33 EITB (Kappa value of 0.2781-0.2117) compared to coproantigen ELISA and serum antigen ELISA. Although there is not a good agreement between the antibody and antigen test.Conclusion: This study found that the performance of rT4/rES33 EITB compared to copro antigen ELISA and serum antigen ELISA were fair and because the agreement was not good between the antibody and antigen test the, selection of a test must be carefully made, with consideration of what is needed. Keywords:Taenia solium diagnosis; coproantigen ELISA; immunodiagnosis; Ag-ELISA; recombinant T24/ES33 EITB

753. Performance Characteristics of Diagnostic Assays in Blastomycosis

Background Blastomycosis has historically been a difficult diagnosis to establish, often initially misdiagnosed as bacterial pneumonia. Serologic assays and polymerase chain reaction (PCR) tests are available, but their performance is not well defined. The objective of this study was to characterize their performance. Methods Subjects were identified via chart review of patients diagnosed with blastomycosis from 2005 to 2020. A definitive diagnosis was based on fungal culture, histopathology, or cytology. Performance characteristics of the Blastomyces antibody enzyme linked immunosorbent assay (ELISA), immunodiffusion (ID), complement fixation (CF), urine and serum antigen ELISAs, and PCR were evaluated in patients with confirmed blastomycosis. Data on patient demographics, location of disease, and mortality was also collected. Results We identified 193 patients with blastomycosis. The mean age was 51.8 years (range, 11-84) and 73.6% of patients were male. 42.5% resided in Minnesota, 18.1% in Wisconsin, and 12.9% in Iowa. Diagnosis was based on culture in 142 (73.2%) or histopathology/cytology in 67 (34.7%) patients. Granulomatous inflammation was present in 73.1% (38/52) while 21.2% (41/193) had evidence of extrapulmonary dissemination. The antibody, ID, and CF assays were positive in 43.5% (37/85), 35.1% (33/94) and 20.5% (8/39) of patients, respectively. Sensitivity of Blastomyces PCR was 40% (4/10) in sputum and 75% (21/28) in bronchoalveolar lavage (BAL) fluid. Blastomyces urine and serum antigen tests were positive in 68% (34/50) and 50% (9/18) of cases, respectively, while the urine antigen was positive in 63.6% (7/11) of disseminated cases. Patients had a positive Histoplasma urine antigen test in 54.1% (20/37) and Aspergillus galactomannan in BAL in 34.8% (8/23) of cases. Serum beta-D-glucan test was positive in 16.7% (2/12). 90-day mortality was 21/193 (10.9%) and median time from diagnosis to death was 18 days. Conclusion In this cohort, Blastomyces urine antigen was the most sensitive noninvasive test, with similar performance in pulmonary and disseminated disease. However, its utility is limited by poor specificity due to cross-reactivity. Blastomyces PCR from BAL fluid demonstrated the highest sensitivity. Blastomyces antibody, ID, and CF had poor sensitivity. Disclosures All Authors: No reported disclosures

Advances in Diagnosis of Progressive Pulmonary and Disseminated Coccidioidomycosis

Background Antibody detection is the main method for diagnosis of coccidioidomycosis, but it has limitations. The Coccidioides antigen enzyme immunoassay is recommended for testing cerebrospinal fluid in suspected meningitis. Reports on urine and serum antigen detection evaluated small numbers of patients who were mostly immunocompromised. The purpose of this study was to assess the accuracy of combined antibody and antigen detection for diagnosis. Methods A retrospective study, including all patients in whom Coccidioides antigen detection in serum was performed between January 2013 and May 2017, was conducted at Valleywise Health Medical Center (formerly Maricopa Integrated Health System). Sensitivity and specificity of antigen and antibody were evaluated in 158 cases and 487 controls. Results The sensitivity of antibody detection by immunodiffusion (ID) was 84.2%. The sensitivity of antigen detection was 57.0% if both urine and serum were tested and 36.7% if urine alone was tested. The sensitivity of combining antigen and ID antibody detection was 93.0%. The sensitivity of urine and serum antigen detection was 55.4% in proven and 58.7% in probable cases, 79.1% in disseminated and 41.6% in pulmonary cases, and 74.7% in immunocompromised and 40.0% in immunocompetent patients. Specificity was 99.4% for antigen detection and 96.5% for ID antibody detection. Diagnostic accuracy was 95.4% for ID antibody and antigen detection, 93.6% for ID antibody alone, and 89.1% for pathology or culture. Conclusions These findings support combined antibody and antigen detection for diagnosis of progressive coccidioidomycosis. The diagnosis may have been missed if antigen detection was not performed.