A process in which a symbiont interferes with, inhibits or disrupts a cytoplasmic pattern recognition receptor signaling pathway in a host organism by reducing the activity of host IRF3 (interferon regulatory factor-3). IRF3 is a transcription factor in the RIG-I/MDA-5 signaling pathway. Viral infection triggers phosphorylation of cytoplasmic IRF3, which allows IRF3 to form a homodimer, migrate to the nucleus, and activate transcription of IFN-alpha and IFN-beta genes.
suppression by virus of host interferon regulatory factor 3