Lorenzo Zammarchi1, Maria Grazia Colao2, Antonia Mantella3, Teresa Capobianco2, Gianna Mazzarelli2, Nunziata Ciccone2, Seble Tekle Kiros4, Elisabetta Mantengoli4, Gian Maria Rossolini5, Alessandro Bartoloni6. 1. Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy; Infectious and Tropical Diseases Unit, Careggi University and Hospital, Florence, Italy; Referral Center for Tropical Diseases of Tuscany, Infectious and Tropical Diseases Unit, Careggi University Hospital, Florence, Italy. 2. Clinical Microbiology and Virology Unit, Careggi University and Hospital, Florence, Italy. 3. Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy; Referral Center for Tropical Diseases of Tuscany, Infectious and Tropical Diseases Unit, Careggi University Hospital, Florence, Italy. 4. Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy. 5. Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy; Clinical Microbiology and Virology Unit, Careggi University and Hospital, Florence, Italy. 6. Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy; Infectious and Tropical Diseases Unit, Careggi University and Hospital, Florence, Italy; Referral Center for Tropical Diseases of Tuscany, Infectious and Tropical Diseases Unit, Careggi University Hospital, Florence, Italy. Electronic address: alessandro.bartoloni@unifi.it.
Abstract
BACKGROUND: Dengue (DENV) and Zika virus (ZIKV) are important mosquito-transmitted viruses. OBJECTIVES: To investigate the performance of Standard F, Fluorescence Immunoassay (FIA, SD Biosensor Inc., Suwon, South Korea) providing results in 15 min to detect DENV IgG, IgM and NS1Ag, and ZIKV IgG, IgM, and Ag. STUDY DESIGN: A well-characterized panel of patient samples (11 acute DENV, 11 acute ZIKV, 10 past DENV, 10 past ZIKV infection, 36 with other conditions) were tested with the FIA test. RESULTS: In acute DENV infection, the combination of FIA-NS1Ag and/or IgM positivity showed a sensitivity of 100%. In past DENV, FIA-IgG test showed a sensitivity of 70%. Specificity of FIA-DENV NS1Ag, IgG, and IgM was 87.5%, 83.5%, and 91.7%, respectively. The sensitivity of FIA-ZIKV IgM and FIA-ZIKV Ag, in confirmed acute infection, was 72.7% and 9.1%, respectively. FIA-ZIKV Ag did not improve the sensitivity in detecting acute ZIKV infection, being positive only in one IgM positive sample. In past ZIKV infection (32-183 days after symptom onset), FIA-ZIKV IgG and IgM showed a sensitivity of 40% and 80% respectively, generating an overall 90% sensitivity. Specificity of FIA-ZIKV Ag, IgM, and IgG was 92.6%, 100%, and 97%, respectively. CONCLUSION: FIA test, a rapid and easy to perform assay, showed high sensitivity to detect acute DENV infection, but lower in acute ZIKV infection. In past ZIKV infections, the best performance of FIA test is obtained by combining detection of IgG and IgM.
BACKGROUND: Dengue (DENV) and Zika virus (ZIKV) are important mosquito-transmitted viruses. OBJECTIVES: To investigate the performance of Standard F, Fluorescence Immunoassay (FIA, SD Biosensor Inc., Suwon, South Korea) providing results in 15 min to detect DENV IgG, IgM and NS1Ag, and ZIKV IgG, IgM, and Ag. STUDY DESIGN: A well-characterized panel of patient samples (11 acute DENV, 11 acute ZIKV, 10 past DENV, 10 past ZIKV infection, 36 with other conditions) were tested with the FIA test. RESULTS: In acute DENV infection, the combination of FIA-NS1Ag and/or IgM positivity showed a sensitivity of 100%. In past DENV, FIA-IgG test showed a sensitivity of 70%. Specificity of FIA-DENV NS1Ag, IgG, and IgM was 87.5%, 83.5%, and 91.7%, respectively. The sensitivity of FIA-ZIKV IgM and FIA-ZIKV Ag, in confirmed acute infection, was 72.7% and 9.1%, respectively. FIA-ZIKV Ag did not improve the sensitivity in detecting acute ZIKV infection, being positive only in one IgM positive sample. In past ZIKV infection (32-183 days after symptom onset), FIA-ZIKV IgG and IgM showed a sensitivity of 40% and 80% respectively, generating an overall 90% sensitivity. Specificity of FIA-ZIKV Ag, IgM, and IgG was 92.6%, 100%, and 97%, respectively. CONCLUSION:FIA test, a rapid and easy to perform assay, showed high sensitivity to detect acute DENV infection, but lower in acute ZIKV infection. In past ZIKV infections, the best performance of FIA test is obtained by combining detection of IgG and IgM.