“…Negative controls were RNA extracted from FFPE cell culture controls or tissue specimens from persons with previously confirmed infection with the following viruses: dengue types 1–4, West Nile, yellow fever, Japanese encephalitis, St. Louis encephalitis, eastern and western equine encephalitis, chikungunya, herpes, parvovirus B19, cytomegalovirus, adenovirus, enterovirus, rubella, Powassan, and Lacrosse. We extracted RNA from FFPE tissues of all 52 case-patients (multiple FFPE tissue blocks per patient) by using an optimized extraction protocol as previously described ( 26 ) and tested the samples by newly developed Zika virus NS5 and E-gene RT-PCR and by RT-PCR for dengue and chikungunya viruses ( 27 , 28 ). RT-PCR assays were performed by using a QIAGEN OneStep RT-PCR Kit (Valencia, CA, USA) and 5 μl of RNA template, according to the manufacturer’s instructions.…”