A Review on Human Orf: A Neglected Viral Zoonosis

Abstract

Orf virus (ORFV) is the etiologic agent of Orf or ecthyma contagiosum in humans but primarily affects different domestic and wild animals. The disease mostly affects sheep, goats and other small wild ruminants and spreads to humans through direct contact with infected animals or by way of contaminated fomites worldwide. ORFV is taxonomically classified as a member of the genus Parapoxvirus. It is known to have tolerance to inactivation in a drier environment, and it has been recovered from crusts after several months to years. Among immunocompetent people, the lesions usually resolve by its natural course within a maximum of 8 weeks. In immunosuppressed patients, however, it needs the use of various approaches including antiviral, immune modifier or minor surgical excisions. The virus through its association with divergent host ranges helps to develop a mechanism to evade the immune system. The relative emergence of Orf, diagnosed on clinical ground among human cases, in unusual frequencies in southwest Ethiopia between October 2019 and May 2020, was the driver to write this review. The objective was to increase health care providers' diagnostic curiosity and to bring the attentiveness of public health advisors for prevention, control and the development of schemes for surveillance of Orf zoonosis in a similar setting like Ethiopia.

Genome-Wide Analysis and Molecular Characterization of Orf Virus Strain UPM/HSN-20 Isolated From Goat in Malaysia

“…However, in severe cases, complications from fly infestation and secondary infection by bacteria and fungi have a significant impact leading to increased death of young animals, decrease in optimum productivity, and restriction of domestic and international trade ( Bala et al, 2018b ; Lawal et al, 2021 ). For zoonotic infection, in immunocompetent individuals, human Orf is localized and self-limiting, and disease resolves spontaneously within weeks ( Hasheminasab et al, 2016 ; Kassa, 2021 ). In immunocompromised patients, complications such as lymphangitis, erythema multiforme, and toxic erythema have been reported ( Lederman et al, 2007 ; Cubells et al, 2016 ).…”

Parapoxvirus Interleukin-10 Homologues Vary in Their Receptor Binding, Anti-Inflammatory, and Stimulatory Activities

“…ORFV infects the muzzle of sheep and goats, PCPV and BPSV infect the teats of cattle and mouths of calves, RDPV infection of red deer occurs in the velvet of stags around the face and mouths of fawns, while GSPV infection of the skin and oral mucosa has been reported in seals and sea lions. Zoonotic infections of human skin have also been reported for these parapoxviruses [ 23 , 62 , 63 , 64 , 65 ]. Lesions from ORFV, PCPV, BPSV, and RDPV infections consistently report of dermal oedema and a dense infiltrate of lymphocytes, neutrophils, and macrophages [ 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ].…”

Recalcitrant giant orf recurrence after amputation: A case report and review of the literature

“…Notably, secondary bacterial infections can occur at the site of skin openings. 21 Orf lesions usually regress and heal spontaneously in 3–6 weeks with no scarring. 1 , 2 Previous studies indicated that Orf in humans can be misdiagnosed and they are mostly overtreated with undesired high costs.…”

“…1 , 2 Previous studies indicated that Orf in humans can be misdiagnosed and they are mostly overtreated with undesired high costs. 21 There has not been any report of mortality from Orf in humans. 21 , 22 , 23 , 24 , 25 …”