An investigation of a cluster of parapoxvirus cases in Missouri, February–May 2006

Abstract number: 1733_1059

Lederman E., Tao M., Pue H., Reynolds M., Smith S., Li Y., Zhao H., Sitler L., Mahmutovic A., Emerson G., Hutson C., Bensyl D., Regnery R., Zhu B., Damon I.

Background: Human infections with ``barnyard parapoxvirus'' (i.e. orf virus and pseudocowpox virus) are rarely reported to health departments. From February to May 2006, four cases were reported in Missouri, two of which were evaluated for anthrax infection.

Methods: Survey of the four cases, family members, county veterinarians and a convenience sample of local farmers were conducted. Samples were collected from implicated animals and animal environments (barnyards) for laboratory analysis.

Results: Two additional cases of human orf infection were identified at a community farm. Five of the six cases sought medical care; none of the primary care providers included parapoxvirus infection in their initial diagnosis. The presence of parapoxvirus DNA was confirmed by real time polymerase chain reaction (DNA polymerase gene-ORF25) in 100% of symptomatic animals (n = 9) and 21% of asymptomatic animals (n = 14). Phylogenetic analysis was performed on virus strains, utilising the virion core protein gene (ORF-27) and the extracellular envelope protein genes (ORFs 109 and 110). Twenty-two percent of local farmers surveyed (n = 58) reported having a parapoxvirus infection at least once in their lifetime. Of these 39% sought medical care for their lesion and 67% of them received antibiotic therapy. Of local veterinarians surveyed (n = 14), 43% were consulted for human cases of orf during their practice and 29% reported that they had been consulted for orf virus infections in sheep/goats at least once a year. Fewer veterinarians were consulted for pseudocowpox virus infections in dairy cattle (0% in the last year; 21% ever).

Conclusions: Parapoxvirus infections are common in Missouri livestock handlers and their animals. The use of nonporous gloves while handling any animals in an infected herd/flock is prudent as parapoxvirus DNA was detected in the oral cavities of asymptomatic animals. Human infections may have a clinical appearance similar to cutaneous anthrax, however the mild illness associated with parapoxvirus infected animals provides a key point of differentiation.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
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