An updated review of avian-origin Tembusu virus: a newly emerging avian Flavivirus

Abstract

Tembusu virus (TMUV, genus Flavivirus, family Flaviviridae) was first isolated in 1955 from Culex tritaeniorhynchus mosquitoes in Kuala Lumpur, Malaysia. In April 2010, duck TMUV was first identified as the causative agent of egg-drop syndrome, characterized by a substantial decrease in egg laying and depression, growth retardation and neurological signs or death in infected egg-laying and breeder ducks, in the People's Republic of China. Since 2010, duck TMUV has spread to most of the duck-producing regions in China, including many of the coastal provinces, neighbouring regions and certain Southeast Asia areas (i.e. Thailand and Malaysia). This review describes the current understanding of the genome characteristics, host range, transmission, epidemiology, phylogenetic and immune evasion of avian-origin TMUV and the innate immune response of the host.

Avian Flavivirus Enters BHK-21 Cells by a Low pH-Dependent Endosomal Pathway

“…Duck Tembusu virus (DTMUV) is a novel pathogenic member of the flaviviridae family and was first reported in South-Eastern China in 2010 in the coastal provinces [31]. The rapid spread of the disease can cause a serious decline in the egg production of laying ducks and neurological symptoms in ducks.…”

Serological evidence of duck Tembusu virus infection in free-grazing ducks, Thailand

“…This disease is primarily characterized by a massive decrease in egg production and severe neurological disorders with almost 100% morbidity and up to 30% mortality (Su et al., ; Thontiravong et al., ). DTMUV infects a wide range of avian species, including ducks, chickens, geese, pigeons, and sparrows (Chen et al., ; Han et al., ; Tang et al., ; Yun, Ye, Ni, Zhang, & Zhang, ; Zhang, Chen, Mahalingam, Wang, & Cheng, ). However, DTMUV‐causing disease occurs primarily in ducks and almost all species of duck can be infected with DTMUV (Zhang et al., ).…”

The continued threat of emerging flaviviruses

“…Host proteins classically defined as receptors are essential for the entry of viruses because they catalyse critical conformational events. For example, the CD4 molecule on T lymphocytes enables conformational transitions in the human immunodeficiency virus type 1 GP120 protein required for viral membrane fusion 14 . While host factors that increase the efficiency of flavivirus binding and infection of cells have been identified, they are not required to trigger the structural transitions that propel viral membrane fusion; instead, these are defined as attachment factors.…”

“…The epidemic potential of flaviviruses reflects many factors related to the unique characteristics of their insect vectors, the consequences of poorly planned urbanization that creates ideal arthropod breeding habitats, the geographical expansion of vectors, changing environmental conditions and extensive global travel 8,9 . Beyond arthropods and humans, flaviviruses are also known to infect a wide array of animal species and can be important veterinary pathogens that threaten economically important domesticated animals [10][11][12][13][14] . These vertebrate animal hosts may constitute important stable reservoirs and contribute to defining conditions that support the introduction of new viral species and transmission among humans 15 .…”