Coinfection by Vaccinia virus and an Orf virus–like parapoxvirus in an outbreak of vesicular disease in dairy cows in midwestern Brazil

Abstract

The current report describes an outbreak of vesicular disease affecting dairy cows in midwestern Brazil in which a coinfection with 2 poxviruses-Vaccinia virus (VACV) and a parapoxvirus-was demonstrated. Milking cows presented vesicles, painful reddish or whitish papules, and scabby proliferative lesions in the teats and udder, in a clinical course of approximately 10-21 days. Histologically, multifocal areas of moderate to severe acanthosis, spongiosis, hypergranulosis, and parakeratotic or orthokeratotic hyperkeratosis with adjacent focally extensive ulcers were observed in the epidermis. Rounded eosinophilic inclusion bodies were observed in the cytoplasm of epithelial cells of areas with acanthosis or necrosis. Moderate inflammatory infiltrate of lymphocytes, plasma cells, neutrophils, and macrophages were observed in some dermal areas. Two people milking the affected cows developed lesions on the hands, painful papules which progressed to ulcerative and scabby lesions in 4-7 days. Electron microscopy of scabs from 1 cow revealed the concomitant presence of orthopoxvirus and parapoxvirus particles. Scabs from 2 cows were positive by polymerase chain reaction for the parapoxvirus B2L gene; 1 of the scabs was also positive for the VACV vgf gene. Nucleotide sequencing of the B2L amplicon revealed a similarity of 96-99% with Orf virus (ORFV) and lower identity with Pseudocowpox virus (92-95%) and Bovine papular stomatitis virus (85-86%). Nucleotide sequencing of a region of parapoxvirus DNA polymerase gene revealed a high similarity (98-100%) with ORFV sequences. Thus, an unusual coinfection with VACV and a parapoxvirus, likely ORFV, was demonstrated in the outbreak.

Zoonotic parapoxviruses detected in symptomatic cattle in Bangladesh

“…In bovines, vaccinia and buffalopox virus infections (orthopoxviruses) can engender high morbidity, with symptoms including malaise, anorexia, and pustular or ulcerated lesions or nodules on the teats and muzzles of adult and juvenile animals, respectively [ 1 , 3 , 7 , 8 ]. Symptoms of bovine infection with bovine papular stomatitis virus (BPSV) and pseudocowpox virus (PCPV) (parapoxviruses) can be similar, involving painful erosive papules or vesicles on the muzzle, lips and teats.…”

[RETRACTED ARTICLE] Bovine Vaccinia in dairy cattle and suspicion of vesicular disease on milkers in Brazil

“…According to the information present in the 420 questionnaires applied at human health care centers, the clinical symptoms presented by the milkers were characteristic of poxviruses (SANT'ANA et al, 2013). However, in 27.61% of human cases with vesicular lesions suspected of being VACV, there was no laboratory confirmation, due to the absence of local health care centers able to perform the analysis, showing a deficiency in the human health care system regarding the assistance of this occupational zoonosis (SILVA-FERNANDES et al, 2009).…”

Evaluating anti-Orthopoxvirus antibodies in individuals from Brazilian rural areas prior to the bovine vaccinia era

“…VACV infection causes lesions on the teats and udders of dairy cattle, leading to a decrease in milk production. VACV is the cause of a zoonotic disease known as bovine vaccinia (BV) and can be transmitted to humans by direct contact with infected animals during milking, resulting in lesions on the hands and arms ( Damaso et al 2000 , Trindade et al 2003 , 2007 , 2009 , Leite et al 2005 , Lobato et al 2005 , Megid et al 2008 , Silva-Fernandes et al 2009 , Abrahão et al 2010a , Schatzmayr et al 2011 , de Assis et al 2013 , de Sant’Ana et al 2013 ). The lesions evolve from macules to papules to vesicles to pustules, which ulcerate and result in scar formation.…”