This tick-derived isolate was determined by serologic methods to be related to a virus previously cultured from the blood of two children with mild febrile illnesses in Quaranfil, Egypt ( 32). Quaranfil virus (QRFV) is a heretofore-unclassified arbovirus isolated in 1953 from ticks ( Argas arboreus) collected near Cairo, Egypt, and subsequently passaged in mice and Vero cells. Recent epidemics of West Nile, chikungunya, dengue, and yellow fever illustrate the importance of understanding the basic virology of arboviruses. Based on phylogenetic analyses, virion ultrastructural features, and the unique end-terminal sequences identified, we propose that QRFV, JAV, and LKCV comprise a novel genus of the family Orthomyxoviridae.Īrboviral infections are an important and emerging cause of human illness. QRFV and JAV PB1 and HA shared 80% and 70% amino acid identity to each other, respectively the LKCV PB1 fragment shared 83% amino acid identity with the corresponding region of QRFV PB1. The complete open reading frames of PB1 and HA were sequenced for JAV, while a fragment of PB1 of LKCV was identified by mass sequencing. QRFV is known to cross-react serologically with two other unclassified viruses, Johnston Atoll virus (JAV) and Lake Chad virus (LKCV). The end-terminal sequences of QRFV are conserved between segments and are different from those of the known orthomyxovirus genera. The fifth sequenced segment shared no detectable similarity to any protein and is of uncertain function. Proteins with limited amino acid similarity to conserved domains in polymerase (PA, PB1, and PB2) and hemagglutinin (HA) genes from known orthomyxoviruses were predicted to be present in four of the segments. The genome of this virus is comprised of multiple RNA segments five were completely sequenced. We used high-throughput sequencing to classify QRFV as a novel orthomyxovirus. It has subsequently been isolated in multiple geographic areas from ticks and birds. Quaranfil virus (QRFV) is an unclassified arbovirus originally isolated from children with mild febrile illness in Quaranfil, Egypt, in 1953.
Arboviral infections are an important cause of emerging infections due to the movements of humans, animals, and hematophagous arthropods.
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