A Novel Human Acute Encephalitis Caused by Pseudorabies Virus Variant Strain

Abstract

Background Pseudorabies virus (PRV) is a common pathogen in multiple animal species particularly in pigs. However, PRV infection in humans is rare and to the best of knowledge, PRV has never been isolated from human cases before. Methods Four acute encephalitis cases in humans were confirmed as PRV infection based on clinical symptoms, laboratory diagnosis, and metagenomic next-generation sequencing (mNGS). Cerebrospinal fluid (CSF) samples were collected and applied for virus isolation. Etiological and genetic characteristics of this PRV human isolate were further determined. Results The patients manifested respiratory dysfunction and acute neurological symptoms. The mNGS revealed PRV specific nucleotide sequences in patients’ CSF samples (7-6198 reads and 0.2446%-80.58% coverage). The PRV envelope glycoprotein B antibody, glycoprotein E antibody, and neutralizing antibody were positively detected. For the first time, a PRV strain, designated hSD-1/2019, was isolated and identified from one CSF sample, and transmission electron microscopy revealed hSD-1/2019 had typical morphology similar to swine PRV. Phylogenetic analysis illustrated that hSD-1/2019 was genetically closest to those PRV variant strains currently circulating in pigs in China, and this strain showed similar etiological characteristics to Chinese PRV variant strains, while different from Chinese classical strain. Moreover, hSD-1/2019 showed high pathogenicity and induced acute neurological symptoms in pigs. Conclusions A PRV strain was isolated from an acute human encephalitis case. This isolate showed close phylogenetic relationships and similar etiological characteristics to Chinese PRV variant strains, implying the great risk of PRV transmission from pigs to humans.

Effects of physical and chemical factors on pseudorabies virus activity in vitro

“…The freezing temperature was − 80°C, and two thawing temperatures were set: 20°C in air and 37°C in a water bath. The freeze-thaw cycles were repeated in this manner, and samples with a freeze-thaw number of 1,5,10,15,20,25,30,35, and 40 were taken for titer measurement Fig. 6 Storage time vs. virus titer curves.…”

“…The main susceptible animals are swine, cows, sheep, rabbits, mice, cats, and other mammals, while pigeons and chickens can resist PRV infection [1][2][3][4]. Not only are there reports of PRV isolated from people presumed to be infected with PRV but there is also direct evidence that PRV can cross hosts to infect humans [5,6]. The amino acid positions in certain important glycoproteins, namely, gB, gC, gD and gE, may be related to the adaptability of PRV to new hosts and its immune escape from vaccines [7].…”

Effects of physical and chemical factors on pseudorabies virus activity in vitro

“…The main susceptible animals are swine, cows, sheep, rabbits, mice, cats, and other mammals, while pigeons and chickens can resist PRV infection [1; 2; 3; 4]. Not only are there reports of PRV isolated from people presumed to be infected with PRV but there is also direct evidence that PRV can cross hosts to infect humans [5,6]. The amino acid positions in certain important glycoproteins, namely, gB, gC, gD and gE, may be related to the adaptability of PRV to new hosts and its immune escape from vaccines [7].…”

Eleutheroside-b and e in Acanthopanax Senticosus has Anti-PRV Activity via an Enhanced Body Immune Response in Vivo

“…PRV has neurotropism and transsynaptic transmission (Ye et al, 2015) since 2011 due to the emergence of a mutant pseudorabies viral strain. The disease continues to cause substantial economic losses to animal husbandry especially the pork industry (Liu et al, 2020).…”