Molecular Epidemiology of Avian Poxvirus in the Oriental Turtle Dove (Streptopelia Orientalis) and the Biting Midge (Culicoides Arakawae) in the Republic of Korea

Abstract

A total of 600 wild birds were analyzed for the causes of mortality in the Republic of Korea (ROK) from 2011 to 2013. Avian poxvirus (APV) infections were identified as the primary cause of mortality in 39% (29/74) Oriental Turtle Doves (Streptopelia orientalis). At necropsy, all 29 S. orientalis birds, of which, 76% (22/29) were juveniles, had severe diphtheritic lesions in their oral and nasal cavities and on their eyelids, which were the lesions of APV that resulted in mortality. We detected APV infection by chorioallantoic membrane inoculation and molecular study of the partial region of the P4b gene. All isolates belonged to the same APV strain and were identical to strains isolated from several different pigeon species in South Africa. Phylogenetically, the APV strain identified in S. orientalis belonged to subclade A2, which includes isolates from several species of pigeons from different parts of the world, including the United Kingdom, Germany, India, Egypt, Hawaii, Georgia, Hungary, South Africa, Tanzania, and the ROK. This identity indicated that this diphtheritic APV strain may be a potential pathogen of other pigeon species in the ROK and neighboring countries throughout the range of S. orientalis. However, reticuloendotheliosis virus insertion into the APV genome was not detected by PCR in any of the 29 APV infections. An identical strain of APV observed in S. orientalis was also detected in Culicoides arakawae (biting midge), with annual peak populations corresponding to the presence of APV in S. orientalis. Culicoides arakawae may be a primary vector of APV in S. orientalis. Active surveillance of APVs in wild birds and C. arakawae is needed to better understand the epidemiology of APVs, host-vector relationships, and its ecological effects on S. orientalis in the ROK.

A Review on the Prevalence of Poxvirus Disease in Free-Living and Captive Wild Birds

“…The diphtheritic form of the disease is observed most frequently in Psittaciformes, Galliformes, and Columbiformes [13] although it has also been reported in Struthioniformes [21] or Passeriformes [22]. Cutaneous and diphtheritic forms can also occur simultaneously in mixed pox infections [23,24]. In general, diphtheritic and mixed pox infections present higher mortality rates than the cutaneous form [13,22,25], and it shows the expected level of 0.035% derived from the number of species in which APV has been detected/avian species.…”

“…Infected birds are the main reservoir for APV. The most frequent transmission route is via biting insects, mostly midges (Ceratopogonidae) and mosquitoes (Culicidae) [23,30]. Other arthropods vectors have also been reported, sometimes as mechanical vectors such as fleas (Parapsyllus longicornis [31]) and blowflies (Phaenicia sp.)…”

Seasonal Abundance of Culicoides at Yongsan US Army Garrison (USAG) and Camp Humphreys USAG, Republic of Korea, 2010-2013 and 2014-2017

“…Although the abundance of individual species varied between the urban and rural sites, similar numbers of species were collected at both Yongsan (12) and Camp Humphreys (16). In a previous report, C. punctatus and C. nipponensis were the most frequently collected species at a cowshed [8,9], suggesting that these species are attracted to cattle, and reflects their feeding preferences [8,17].…”

“…filarial worms) and veterinary importance. Bluetongue virus was first isolated from a cow in Korea, with infections impacting the economy of the animal industry in Korea [4,5,[13][14][15][16].…”

Isolation and characterization of 89 SNP markers in the oriental turtle dove, Streptopelia orientalis

“…The oriental turtle dove (Streptopelia orientalis) is a widespread polytypic Asian species that breeds from the Ural Mountains to the Pacific coast of the Russian Far East (Brazil 2009;Gibbs et al 2001;Johnson et al 2001;Lee et al 2017). S. orientalis has been listed in the International Union for Conservation of Nature (IUCN), IUCN Red List of Threatened Species (2016), ranging from north (Heilongjiang Province) to south (Hainan Island), and from west (Xinjiang and Tibet) to east (Hong Kong and Taiwan).…”