Vaccinia (smallpox) vaccine is an effective immunizing agent that brought about global eradication of naturally occurring smallpox, as declared by the World Health Organization in 1980. The United States ceased generalized smallpox vaccination in 1972 but reinstated it in 2002 for military personnel and selected healthcare workers (first responders who may be investigating possible cases of smallpox or caring for patients in selected hospitals) after the 2001 bioterrorism attacks. Since reinstitution of the vaccine, reports of transmission of vaccinia virus through contact with military smallpox vaccinees have been published, including four cases of female genital infection. We report a subsequent case of vulvar vaccinia infection acquired during sexual contact with a military vaccinee.

A 4-month-old male infant predisposed to allergic dermatitis acquired wide-spread eczema vaccinatum by contacts with a recently vaccinated sibling. He died of acute purulent peritonitis following a perforation of multiple duodenal ulcers. Fluorescence immunocytochemical and electron microscopic studies on the skin lesions revealed the presence of viral antigens and numerous virus particles compatible morphologically with those of the mature form from the same batch of smallpox vaccine given to the sibling. A large number of virus particles in the developmental form were also predominantly scattered in the cytoplasm of cells at the stratum malpighii of the epidermis as well as in neutrophils and macrophages in the skin lesions. The virus isolation from the skin lesions was done by using the HeLa cells and the human embryonic lung fibroblasts. No abnormal laboratory data were noted in immunoglobulins. On the basis of atrophy of the thymus and other lymphatic tissues and an appearance of large pyroninophilic cells in association with blastoid transformation, the authors discussed a possible participation of the disturbance of cellular immunity secondary to the virus infection in the development of the disease.