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

Abstract

Avian pox is a widespread infection in birds caused by genus Avipoxvirus pathogens. It is a noteworthy, potentially lethal disease to wild and domestic hosts. It can produce two different conditions: cutaneous pox, and diphtheritic pox. Here, we carry out an exhaustive review of all cases of avian pox reported from wild birds to analyze the effect and distribution in different avian species. Avian poxvirus strains have been detected in at least 374 wild bird species, a 60% increase on a 1999 review on avian pox hosts. We also analyze epizootic cases and if this disease contributes to wild bird population declines. We frequently observe very high prevalence in wild birds in remote island groups, e.g., Hawaii, Galapagos, etc., representing a major risk for the conservation of their unique endemic avifauna. However, the difference in prevalence between islands and continents is not significant given the few available studies. Morbidity and mortality can also be very high in captive birds, due to high population densities. However, despite the importance of the disease, the current detection rate of new Avipoxvirus strains suggests that diversity is incomplete for this group, and more research is needed to clarify its real extent, particularly in wild birds.

Transcriptomic responses of Galápagos finches to avian pox virus infection

“…Avian pox contributed to the decline and extinction of bird populations in Hawaii and has been associated with disease in other novel hosts (van Riper III et al, 2002;Williams et al, 2021). In the Galápagos avian pox is prevalent and a cause for concern; however, little is known about the effects of pox infection on Galápagos bird physiology and cellular function.…”

“…Viruses in the genus Avipoxvirus infect birds and are distributed worldwide (Williams, Truchado, & Benitez, 2021). Avian pox is transmitted by direct contact between individuals and mechanically by biting arthropods (Zylberberg, Lee, Klasing, & Wikelski, 2012a).…”

“…Avian pox is transmitted by direct contact between individuals and mechanically by biting arthropods (Zylberberg, Lee, Klasing, & Wikelski, 2012a). Infection typically causes cutaneous lesions on the feet, legs, and face, though in more severe cases it can infect mucous membranes of the respiratory tract (Williams et al, 2021). Mild cutaneous pox infections may not be debilitating; however, large lesions can impede vision, mobility and feeding ability.…”

“…Mild cutaneous pox infections may not be debilitating; however, large lesions can impede vision, mobility and feeding ability. Avian pox causes more severe disease in insular bird populations that are naïve to the virus (Williams et al, 2021). Pox was implicated in the decline and extinction of several Hawaiian honeycreepers (van Riper III, van Riper, Hansen, & Hackett, 2002)and has recently caused outbreaks of disease in tits (Paridae) in Great Britain (Lawson et al, 2012), magellanic penguins (Spheniscus magellanicus) on the Atlantic coast of Argentina (Kane et al, 2012), and endemic passerines (Calandrella rufescens and Anthus berthelotti) in the Canary Islands (Smits, Tella, Carrete, Serrano, & López, 2005).…”

Molecular Detection of Avipoxvirus in Wild Birds in Central Italy

“…APV infections have been reported in more than 370 avian species from 23 orders, including domestic and wild birds [3,4,9]. Passeriformes have been found to be frequently infected by APV, but the infection has been often observed in Anseriformes, Galliformes, and Psittaciformes too [9].…”