Emerging Sand Fly-Borne Phlebovirus in China

Abstract

We isolated 17 viral strains capable of causing cytopathic effects in mammalian cells and death in neonatal mice from sand flies in China. Phylogenetic analysis showed that these strains belonged to the genus Phlebovirus. These findings highlight the need to control this potentially emerging virus to help safeguard public health.

Keywords: Bunyavirales; Corfu virus; PCR; Phlebotomus chinensis; Toros virus; Wuxiang virus; amino acid sequences; nucleotide sequences; phleboviruses; polymerase chain reaction; sand flies; sand fly–borne phlebovirus; vector-borne infections; viruses.

Figure 1

Cytopathogenic effect and electron microscopic morphology of baby hamster kidney 21 (BHK-21) cells infected with phlebovirus, China. A) Left panel shows morphology of BHK-21 cells before inoculation with strain SXWX1813-2; right panel shows morphology 3 days after inoculation (original magnification ×200). BHK-21 cells infected with SXWX1813-2 showed reduced adherence and a large number of rounded and exfoliated cells. B) Left panel shows the viral morphology of SXWX1813–2 on ultrathin slices (scale bar 1μm); right panel shows the enlarged viral particle (indicated by arrow) (scale bar 200nm).

Figure 2

Evolution of nucleotide sequences of the large and medium gene segments of WUXV, a new phlebovirus isolated in China. A) Phylogenetic analysis of nucleotide sequences and molecular genetic evolution analysis of the large gene of WUXV isolate SXWX1813-2 (black dot), and reference isolates. B) Phylogenetic analysis of nucleotide sequences and molecular evolution analyses of the medium genes of 17 WUXV isolates, and reference isolates. MEGA 6.0 (https://www.megasoftware.net) and the neighbor-joining method were used for genetic evolution analysis with 1,000 bootstrap replicates. SFTSV, severe fever with thrombocytopenia syndrome virus; WUXV, Wuxiang virus.