Evaluation of Two Comercially available chicungunya virus IgM enzyne-linked Inmunoassay (Elisa) in an endemic region for Chikungunya Dengue and zika virus

KIKUTI, MARIANA; NASCIMENTO, LEILE C J; WEAVER, SCOTT C.; GUILHERME S. RIBEIRO; TAURO LAURA BEATRIZ; POTRILHO M ; MITERMAYER G. REIS; MOREIRA, PATRÍCIA S S; CAMPOS GS; KITRON URIEL

Maryland

Congreso; ASTMH anual meeting; 2019

ASTMH

Objective: To evaluate the diagnostic performance of the Inbios (Seattle, US) and Euroimmun (Luebeck, Germany) chikungunya virus (CHIKV) IgM enzyme-linked immunoassays (ELISAs).Methods: We evaluated the tests? accuracy on sera from 372 patients enrolled in an acute febrile illness surveillance study performed in Salvador, Brazil from Sept/2014 to Jul/2016, a period of simultaneous CHIKV, dengue (DENV), and Zika (ZIKV) virus transmission. We assessed the sensitivity on acute and paired convalescent sera from RT-PCR-confirmed CHIKV cases (collected at median one and 19 days post-onset of symptoms, respectively), and the specificity on sera of RT-PCR-confirmed DENV and ZIKV cases, and on negative patients.Results: The Inbios and Euroimmun tests? sensitivities for acute samples were 4.0% and 10.3%, while for convalescent samples they were 92.4% and 96.9%, respectively. Overall, Inbios IgM ELISA specificities for acute and convalescent samples were 97.7% and 90.5%, respectively, and Euroimmun specificities were 88.5% and 83.9%, respectively.Conclusions: Both tests presented high sensitivity for convalescent samples. However, the Euroimmun test returned more equivocal results and presented a slightly lower specificity, which might result in a higher rate of false positives if the test is used in scenarios of low CHIKV transmission, when the chance of CHIKV infection is lower.