Related Experiment Video
Updated: Jun 2, 2026
09:07
Mouse Footpad Inoculation Model to Study Viral-Induced Neuroinflammatory Responses
Published on: June 14, 2020
Orf parapoxvirus infection from a cat scratch
Jonathan Frandsen1, Mike Enslow, Anneli R Bowen
1University of Utah, Department of Dermatology, Salt Lake City, Utah, USA.
Dermatology Online Journal
|May 10, 2011
Summary
Orf, a viral skin infection usually from sheep or goats, can be transmitted by cats. A novel case shows a woman’s orf infection resolved with topical imiquimod cream.
Area of Science:
- Dermatology
- Infectious Diseases
- Virology
Background:
- Orf (parapoxvirus) is a zoonotic infection typically transmitted from sheep and goats to humans.
- Transmission usually occurs via direct contact with infected animals or contaminated fomites.
Observation:
- A 53-year-old woman developed an enlarging, tender, ulcerated nodule on her dorsal hand.
- The patient reported a history of being scratched by a stray kitten prior to lesion development.
Findings:
- Histopathological examination confirmed orf parapoxvirus infection.
- The lesion resolved completely without scarring after several weeks of treatment with topical imiquimod 5% cream.
Implications:
- This case suggests that transmission of orf virus to humans can occur through cat scratches, a route not previously documented.
- Topical imiquimod may be an effective treatment for orf infections in humans.
Related Concept Videos
01:28Toxoplasmosis
Toxoplasmosis, a zoonotic disease caused by the protozoan Toxoplasma gondii, poses significant public health challenges globally due to its high seroprevalence and varied clinical manifestations. As an obligate intracellular parasite, T. gondii can infect all warm-blooded vertebrates, but felids are its only definitive hosts, shedding unsporulated oocysts into the environment. Humans typically acquire the infection through ingestion of tissue cysts in undercooked meat or oocysts from...
01:20Chickenpox
Chickenpox is an acute, highly contagious disease caused by the varicella-zoster virus (VZV), a double-stranded DNA virus belonging to the Herpesviridae family. Its transmission occurs primarily through the inhalation of respiratory droplets or direct contact with vesicular fluid from skin lesions. The incubation period typically ranges from 10 to 21 days, during which the virus replicates and disseminates through sequential phases within the host. Although generally self-limiting in children,...
01:28Rabies
Rabies is a lethal zoonotic disease caused by a single-stranded, negative-sense RNA virus of the Lyssavirus genus, within the family Rhabdoviridae. Its primary mode of transmission to humans is through bites or saliva-contaminated scratches from infected mammals such as dogs, bats, raccoons, or foxes. Transmission can also occur if infectious saliva contacts abraded skin or intact mucous membranes, including the conjunctiva.Viral Entry and Early ReplicationOnce introduced at the bite or scratch...
01:17Poliomyelitis
Poliomyelitis is caused by poliovirus, a small, non-enveloped, positive-sense RNA virus of the Picornaviridae family and Enterovirus genus. Transmission occurs primarily via the fecal-oral route, often through ingestion of contaminated water or food. The virus initially replicates in the oropharynx and intestinal mucosa, particularly in lymphoid tissues such as the tonsils, Peyer’s patches, and regional lymph nodes. Primary viremia follows, allowing dissemination throughout the body.In most...
01:24Smallpox
Smallpox is a severe contagious disease caused by the Variola major virus, a double-stranded DNA member of the Poxviridae family.Variola major transmission occurs primarily via inhalation of virus-laden droplets or direct contact with infectious scabs. The incubation period averages approximately seven days, although it may range from 7 to 17 days depending on the inoculum and host factors.Clinically, the prodromal phase is marked by an abrupt onset of high fever, malaise, headache, and myalgia.
01:26Rocky Mountain Spotted Fever
Rocky Mountain Spotted Fever (RMSF) is a severe tick-borne illness caused by Rickettsia rickettsii, a Gram-negative, coccobacillary bacterium. This pathogen is an obligate intracellular parasite, requiring a host cell for replication. Transmission occurs through the bite of an infected tick. In the United States, the most important vectors are Dermacentor variabilis (American dog tick) and Dermacentor andersoni (Rocky Mountain wood tick), though other tick species may also serve as vectors.