Am Fam Physician. 2005;71(12):online
to the editor: A 23-year-old active-duty Marine woman presented to an outpatient military clinic in Okinawa, Japan for sexually transmitted disease screening after developing painful vesicular lesions of the labia and vagina. The patient was initially diagnosed with a primary genital herpes outbreak. Viral culture was collected, and the preliminary isolate suggested herpes simplex. The culture was sent to a reference laboratory in Tokyo, Japan, for final identification that revealed vaccinia, the live virus used in the smallpox vaccine. The patient's medical record revealed that she had not received the smallpox vaccine.
Upon further questioning, it was discovered that the patient's sexual partner, also an active-duty Marine, had received the smallpox vaccination (in preparation for deployment to Iraq) approximately seven days before sexual contact with the patient. Four days after this exposure, the patient presented to the clinic with vaginal vaccinia, suggesting inadvertent inoculation.
The smallpox vaccine available in the United States and used by the U.S. military is a live virus preparation of vaccinia virus, a pox-type virus. The vaccine does not contain actual smallpox virus (variola).
Approximately four days after vaccination, an extremely itchy lesion develops at the vaccination site that contains high titers of vaccinia virus, which can be easily transferred to other body sites (autoinoculation) or other persons (inadvertent inoculation) through scratching and negligent hygiene. Transfer of vaccinia virus from the primary site to other body parts or other persons is the most common complication of smallpox vaccination, and is estimated by the Centers for Disease Control and Prevention to occur in 529 persons per 1 million primary vaccinees.1
As biologic warfare continues to be a threat, many people (military, first-responders) will continue to receive the smallpox vaccination. Patients presenting to their family physician with unusual vesicular rashes should be evaluated for exposure to the smallpox vaccine.