The fi nal diagnosis was fulminant peracute bacteremia and septicemia secondary to a primary viral infection associated with nonsuppurative encephalitis. Published etiologic considerations for cetacean nonsuppurative encephalitis include morbillivirus and protozoal infections (2) . A DNA microarray with highly conserved sequences from >1,000 viruses was selected to screen for known and novel viruses (3). Total RNA was extracted from brain tissue and hybridized to a microarray as described (4) . Analysis of the resulting hybridization pattern demonstrated a strong hybridization signal to many oligonucleotide probes on the microarray from the family Flaviviridae, in particular to WNV. Consensus reverse transcription PCR primers (5) targeting WNV were used to confi rm the microarray results. Sequencing of the 261-bp amplicon (GenBank accession no. HQ610502) yielded a sequence with 99% nt identity and 100% aa acid identity to WNV strain OK03 (GenBank accession no. EU155484.1), a strain originally identifi ed in Oklahoma, USA.