Loading...
Vaccination of U.S. military personnel against smallpox had ended in 1990 but was resumed after the terrorist attacks of September 11, 2001. The procedure employs live vaccinia virus, and those immunized are contagious from the time a papule develops at the inoculation site (2–5 days after vaccination) until the scab that forms later falls off (usually by day 21). Spread of the virus occurs by direct skin contact or indirectly through fomites.
Recently, three civilians developed vaccinia infections after contact with newly vaccinated service personnel. In Alaska, an otherwise healthy woman had two shallow vulvar ulcerations, burning, and redness following sexual intercourse with a military serviceman who had been vaccinated 3 days earlier. The patient’s symptoms resolved, and the ulcers healed completely 3 months before a definitive diagnosis was made.
In Indiana, a 28-month-old boy with severe eczema developed vaccinia infection after contact with his father, a military serviceman who had been immunized about 3 weeks before. The child had a papular and vesicular eruption that progressed to involve about 50% of his skin. The eruption was associated with hypothermia, vascular instability, and the need for mechanical ventilation. He received vaccinia immune globulin (VIG) and two antiviral agents and survived with no apparent sequelae. His mother developed facial vaccinia vesicles, which promptly resolved following VIG therapy. Cultures of items in the family home revealed live virus on three objects.
Centers for Disease Control and Prevention (CDC). Vulvar vaccinia infection after sexual contact with a military smallpox vaccinee — Alaska, 2006. MMWR Morb Mortal Wkly Rep 2007 May 4; 56:417-9.
Centers for Disease Control and Prevention (CDC). Household transmission of vaccinia virus from contact with a military smallpox vaccinee — Illinois and Indiana, 2007. MMWR Morb Mortal Wkly Rep 2007 May 18; 56:478-81.
Comment
Vaccinees should wear long-sleeved shirts and cover their inoculation sites with gauze or a similar dressing until the scab spontaneously separates from the skin. They should not share towels or clothing with others. After changing dressings and after touching the immunization site, vaccinees should wash their hands with warm, soapy water or a solution composed of at least 60% alcohol.
Contraindications to inoculation include pregnancy, immunocompromised status, or eczema in the prospective vaccinee or in any household contact. The father of the young boy, therefore, should not have been immunized; his son developed eczema vaccinatum, an infection that had a 30% to 40% mortality rate before the development of VIG, which has reduced mortality to 7%. In both cases, the diagnoses were delayed because clinicians were unaware of the patients’ contact with recently immunized persons. Unexplained vesicular lesions should prompt inquiry about smallpox vaccination in the patient or in a recent contact.