RESUMEN
BACKGROUND: Kawasaki disease (KD) is an acute febrile and eruptive disease with systemic vasculitis predominantly affecting young East Asian children. Recent reports showed that children with KD-like disease from KD low prevalence regions had positive SARS-CoV-2 serology despite a negative SARS-CoV-2 polymerase chain reaction (PCR) in respiratory samples. OBJECTIVES: To describe 3 pediatric Kawasaki Disease patients with false positive SARS-CoV-2 serology. STUDY DESIGN: We retrospectively recruited children with KD diagnosed during the COVID-19 outbreak in Hong Kong. Clinical characteristics and laboratory test results including SARS-CoV-2 PCR results were retrieved. We performed a microparticle-based immunoassay for the detection of IgG against nucleoprotein (NP) and spike protein receptor binding domain (RBD), and a microneutralization assay for the detection of neutralizing antibodies. RESULTS: Three Chinese children with typical KD were identified. They had no epidemiological links with COVID-19 patients and tested negative for SARS-CoV-2 NPA PCR. They were treated with IVIG and aspirin, and were discharged without complications. Subsequently 2 of them were tested positive against anti-RBD and anti-NP antibodies and 1 was tested positive against anti- RBD antibodies. However, microneutralization assay showed that neutralizing antibodies were absent, suggesting a false-positive IgG result. CONCLUSION: Detection of neutralizing antibodies is recommended to confirm previous SARS-CoV-2 infection in IgG-positive but PCR-negative patients.
Asunto(s)
Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales/sangre , Infecciones por Coronavirus/diagnóstico , Inmunoensayo/métodos , Síndrome Mucocutáneo Linfonodular/patología , Neumonía Viral/diagnóstico , Pruebas Serológicas/métodos , Betacoronavirus/inmunología , COVID-19 , Niño , Proteínas de la Nucleocápside de Coronavirus , Reacciones Falso Positivas , Hong Kong , Humanos , Técnicas de Diagnóstico Molecular/métodos , Proteínas de la Nucleocápside/inmunología , Pandemias , Fosfoproteínas , Reacción en Cadena de la Polimerasa/métodos , Estudios Retrospectivos , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus/inmunologíaRESUMEN
The winter 2018/19 influenza season in Hong Kong has been predominated by influenza A(H1N1)pdm09 as at January 2019. We enrolled 2,016 children in three public hospitals in Hong Kong between 2 September 2018 and 11 January 2019. Using the test-negative approach, we estimated high early season effectiveness of inactivated influenza vaccine against influenza A or B of 90% (95% confidence interval (CI): 80-95%) and 92% (95% CI: 82-96%) against influenza A(H1N1)pdm09.
