Development of an IgM-capture ELISA for Coxsackievirus A16 infection

Diagnosis of Coxsackievirus A16 (CA16) infection in China relies mainly on reverse transcription-polymerase chain reaction (RT-PCR) that require expensive equipment and special trained personnel, thus making its wide application in health care settings unlikely. In this study, a novel IgM anti-CA16 assay was developed for the detection of IgM antibodies to CA16 in serum. The responses and diagnostic value of IgM for the CA16 infection were:assessed by testing 1970 serum samples. The results showed that sensitivity of IgM test was 84.6% (259/306, 95% CI: 80.1-88.5), and specificity in control subjects and patients with CA16 HFMD was 99.2% (1508/1520, 95% CI: 98.6-99.6) and 90.3% (14/144, 95% CI: 84.2-94.6), respectively. The IgM positive rate reached 56.3% in the sera collected within the first day after onset, increased continuously to 95.3% at day 5 to day 7 after onset, and then reached 100% after more than 8 days. The cross-reaction rate in patients infected with other non-CA16 enteroviruses was 9.7% (14/144). These results suggest that the IgM anti-CA16 assay offers a rapid, convenient, and reliable method to detect acute CA16 infections. (C) 2010 Elsevier B.V. All rights reserved.