The Nov. 6 Morbidity and Mortality Weekly e-newsletter from the Centers for Disease Control and Prevention cites an August 2009 case report of a 35-year old woman from Pennsylvania who developed rabies vaccinia virus infection as a result of contact with oral rabies vaccination (ORV) bait intended for wildlife. The bait contains liquid vaccinia-rabies glycoprotein (V-RG) recombinant virus vaccine.

The woman was picking blackberries in a rural area where the bait had been recently distributed. Her dog picked up a bait in his mouth and punctured the bait with his teeth. After the dog dropped the bait, the woman picked it up, and V-RG vaccine dripped from the bait onto her right hand and wrist, including sites that had been abraded by blackberry thorns. At the time, the woman was taking several immunosuppressive medications for a medical condition.

On day 4, she reported several red papules on her right hand. Scrapings were collected and on day 5, a real-time polymerase chain reaction assay of the scrapings tested positive for nonvariola Orthopoxvirus DNA. Subsequent testing performed at CDC confirmed the presence of vaccinia virus DNA and rabies virus G protein DNA in papule material and serologic evidence of rabies virus neutralizing antibodies. Neither Orthopoxvirus IgG nor IgM antibodies were detected.

The woman was hospitalized. Physical examination on admission showed multiple papules on erythematous bases on the patient's right hand, wrist, and arm, including three that appeared to be early vesicles. Because of the patient's immune suppression and concerns about progressive vaccinia, she was administered a single dose (6,000 IU/kg) of VIGIV (Cangene Corporation, Winnipeg, Canada) provided by CDC. Contact precautions were utilized while the patient was hospitalized.

On day 9, she had 26 classic vaccinia virus lesions, including one on a site on her right arm that might not have been in contact with the vaccine initially. The patient was afebrile and not experiencing symptoms related to her inflammatory bowel disease. However, on day 11, she experienced myalgia and headache; she had pronounced redness and edema in her right hand accompanied by right axillary adenopathy. The patient remained afebrile, but was taking an antipyretic pain medication. At that time, her physician decided that to prevent exacerbation of her inflammatory bowel disease the patient soon would need to restart her immunosuppressive medications.

On day 12, in an attempt to reduce viral replication and prevent progressive vaccinia, a second 6,000 IU/kg dose of VIGIV was administered along with the investigational antiviral agent, ST-246 (SIGA Technologies, Corvalis, Oregon). The ST-246 was administered orally for 14 days after a compassionate use authorization was approved by the Food and Drug Administration.

By day 28, all scabs from her lesions had separated and her underlying inflammatory bowel disease condition was stable. The patient remained Orthopoxvirus IgM negative throughout her illness.

Public health agencies should educate the public, and particularly pet owners, regarding potential hazards associated with handling wildlife rabies vaccine baits and should provide guidance for persons exposed to this vaccine.

Read the full case report and see photos.