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Vaccinia Virus Infection After Sexual Contact with a Military Smallpox Vaccinee --- Washington, 2010

On March 1, 2010, the Washington State Department of Health (WADOH) notified Public Health -- Seattle & King County (PHSKC) of a suspected case of contact transmission of vaccinia virus from sexual contact with a member of the military who had been vaccinated against smallpox. Vaccinia virus infection after sexual contact has been reported previously (1--4). Despite the patient's exposure history and clinical presentation, the diagnosis initially was not considered by the patient's physician, who ordered laboratory testing for several common sexually transmitted infections. The patient was seen by a second physician and referred to an infectious disease specialist, who obtained a swab sample of a genital lesion for laboratory testing for vaccinia virus. Vaccinia virus was confirmed by the Washington State Public Health Laboratory (WAPHL) and the CDC Poxvirus Laboratory. The patient resided in a household with an immunosuppressed renal transplant recipient. Appropriate contact precautions were recommended to the patient. No additional cases of contact transmission were reported. This report describes the patient's clinical course and the associated epidemiologic investigation. Health-care providers caring for U.S. military personnel or their contacts should consider vaccinia virus infection in the differential diagnosis of clinically compatible genital lesions. Contact precautions should be emphasized to all persons who are vaccinated, as well as their contacts with unexplained lesions that might represent vaccinia infection from contact transmission.

Case Report

On February 26, 2010, a patient in her 20s visited an urgent-care clinic and reported a 2-day history of painful, ring-shaped, vaginal "swellings." She denied any history of fever or other symptoms. Physical examination revealed a single, raised, circular lesion with central ulceration on the right labia majora. The patient reported that her boyfriend was a military service member who recently was vaccinated for smallpox, and she expressed concern that the lesions might have been related to this exposure. The health-care provider did not make a diagnosis, but cultured for gonorrhea, chlamydia, and herpes virus, and treated the patient with valacyclovir, azithromycin, cefazolin, and ceftriaxone, with instructions to follow-up with her primary-care physician in the next several days.

Three days later, on March 1, the patient visited a different clinic because of increased pain at the site of the lesion. She said she noted new sores in her vaginal and vulvar areas and an enlarged and tender right inguinal lymph node. The patient again expressed concern about the possibility of vaccinia virus infection. On physical examination, additional painful, circular, nonvesicular lesions with raised borders and ulcerated centers were present on both labia minora and within the vaginal vault. The lesion on the right labia majora was approximately 1.5 cm in diameter. Examination also revealed an enlarged and tender right inguinal lymph node, and shotty, tender, left inguinal lymphadenopathy. The physician sent a lesion swab specimen in viral transport media to a commercial laboratory for herpes simplex virus and vaccinia virus testing and referred the patient to an infectious disease specialist for further evaluation. The preferred specimen for vaccinia virus testing is a swab placed in a dry tube, not viral transport media; therefore, the swab was not tested for vaccinia virus, and PHSKC facilitated collection of a second swab specimen during the patient's referral visit.

The next day, on March 2, the infectious disease specialist's examination showed a single 1.5--2.0 cm inguinal lymph node. A 3 cm region of ulceration was present in the vaginal vault, and three ulcers ranging in size from 1 cm to 2 cm were present on the vulva. The cervix appeared normal. The specialist made a diagnosis of suspected vaccinia infection, collected a swab specimen from an ulcer, and submitted it to WAPHL, a member of the Laboratory Response Network, for testing for vaccinia virus infection. The specialist prescribed Vicodin for pain and counseled the patient about infection control. A week later, the patient followed up with the same infectious disease specialist, who noted healing vaginal lesions that were smaller and more superficial, with some granulation tissue.

On March 3, WAPHL tested the clinical specimen (lesion swab) using real-time polymerase chain reaction (PCR) for orthopoxvirus and for nonvariola orthopoxvirus, both of which yielded positive findings. WAPHL called the CDC Poxvirus Program on March 3, and a duplicate swab was sent to CDC for confirmatory testing. CDC confirmed the WAPHL results and confirmed the presence of vaccinia virus in the patient's specimen using a vaccinia-specific real-time PCR assay.

Epidemiologic Investigation

On March 1, WADOH was contacted by the commercial laboratory with questions about vaccinia testing. WADOH obtained contact information for the patient and provider and notified PHSKC. The patient's clinical presentation, epidemiologic history, and positive vaccinia virus test results met CDC's case definition for vaccinia contact transmission (5). PHSKC interviewed the patient to determine whether any close contacts were at risk for infection or severe complications due to vaccinia virus infection, and also to reinforce infection control techniques (6).

The patient's boyfriend received a smallpox vaccination on February 15 at a military base in a neighboring county. On February 20, the boyfriend removed the bandage covering his vaccination site; that same day, the couple had unprotected sexual intercourse preceded by digital vaginal contact. Four days later (on February 24), the first lesion appeared on the patient's right labia majora.

The patient had a history of eczema as a child, but had not been symptomatic since she was age 10 years. She had no history of smallpox vaccination. She reported no underlying medical conditions or history of sexually transmitted diseases. Her boyfriend was her only sex partner, and he had not reported any genital lesions.

The patient shared a home with three other persons: two did not have any underlying risk factors for vaccinia complications, but the third had received a kidney transplant in 2001 and was on immunosuppressant drugs. This person previously served in the military and might have been vaccinated for smallpox in the past, but PHSKC was unable to obtain verification through medical records. The patient did not report any other social or familial contacts who were immunosuppressed, had a history of dermatologic conditions, or were pregnant. The boyfriend vaccinee could not be interviewed because he was deployed overseas. However, interviews with the vaccinee's mother and his roommate revealed no other close contacts at high risk for serious complications from vaccinia virus infection. The Military Vaccine Agency (MILVAX)* was notified of this case.

Interviews with the three health-care providers who examined the patient revealed that they had worn gloves and followed CDC-recommended contact precautions. A total of three health-care workers who were exposed to the patient and the laboratories who handled her clinical specimens were alerted of the diagnosis; no underlying health conditions were identified among the exposed health-care workers, and none had symptoms of vaccinia.

Reported by

J Pauk, MD, M Gonchar, MD, The Polyclinic, Seattle; A Baer, PhD, TS Kwan-Gett, MD, J Duchin, MD, Public Health -- Seattle & King County; C DeBolt, MPH, D Russell, Washington State Dept of Health. M Reynolds, PhD, K Wilkins, W Davidson, MPH, Y Li, PhD, K Karem, PhD, I Damon, MD, PhD, Div of Viral and Rickettsial Diseases, National Center for Emerging and Zoonotic Infectious Diseases; M Kay, DVM, AM McCollum, PhD, EIS officers, CDC.

Editorial Note

After a person is vaccinated with vaccinia, the vaccination site contains infectious virus from the time of papule formation until the scab separates from the skin (a period of approximately 2--3 weeks). During this period, a risk exists for inadvertent inoculation to another body site or another person (7). The most frequently reported sites of vaccinia infections caused by unintentional transfer are the face, nose, mouth, lips, genitalia, anus, and eye (5). The case described in this report was in a female patient who was exposed to vaccinia virus via digital vaginal contact with a recent military smallpox vaccinee.

The U.S. military reinitiated routine smallpox vaccination for service members in 2002. The case described in this report is one of several that have been reported after sexual contact with a recent military vaccinee (1--3). In addition, CDC is aware of four similar unpublished cases in North Carolina, Minnesota, California, and Kansas in the past 12 months. Each of these occurred in female patients presenting with vaginal lesions who had a history of sexual contact with a military vaccinee; each infection was confirmed as vaccinia virus by laboratory testing. Increased awareness of the potential for vaccinia virus infections is recommended for health-care providers and public health departments caring for military personnel and their contacts. To help prevent transmission of the virus, health-care providers should educate vaccinees about methods to prevent transmission and inadvertent autoinoculation. These methods include frequent hand washing, keeping the vaccination site covered with a bandage, and not sharing linens or clothing with unvaccinated persons (5,6).

The first physician who saw the patient on February 26 only pursued laboratory testing for common sexually transmitted infections, although the patient stated that she had recent sexual contact with a smallpox vaccinee. Gonorrhea and chlamydia infections have different clinical presentations than the case described in this report. Primary syphilis infections generally present with a painless ulcer at the site of invasion. Clinicians should suspect infections with vaccinia virus in patients with vesiculopapular rashes and known exposures to recent smallpox vaccinees, including sexual contact.

Health-care providers should contact their state or local health department for information on testing specimens for the presence of vaccinia; testing is available at laboratories participating in the Laboratory Response Network. Health-care providers should report vaccinia contact transmission as a vaccine adverse event to their local health authority and/or to the Vaccine Adverse Event Reporting System (VAERS). Surveillance case definitions are available for adverse events resulting from vaccinia vaccination (5). Vaccinia virus infections via contact transmission are not nationally notifiable; however, public health departments are encouraged to report these infections to CDC.


  1. Muzny CA, King H, Byers P, et al. Vulvar vaccinia infection after sexual contact with a smallpox vaccinee. Am J Med Sci 2009;337:289--91.
  2. CDC. Vulvar vaccinia infection after sexual contact with a military smallpox vaccinee---Alaska, 2006. MMWR 2007;56:417--9.
  3. Lorich MF, Smith SB, Bessiner GT, Olivere JW. Conjugal transfer vaccinia. J Am Acad Dermatol 2004;51:460--2.
  4. Humphrey DC. Localized accidental vaccinia of the vulva. Report of 3 cases and a review of the world literature. Am J Obstet Gynecol 1963;86:46--9.
  5. CDC. Surveillance guidelines for smallpox vaccine (vaccinia) adverse reactions. MMWR 2006;55(No. RR-1).
  6. CDC. Smallpox vaccination and adverse reactions: guidance for clinicians. MMWR 2003;52(No. RR-4).
  7. Koplan JP, Marton KI. Smallpox vaccination revisited: some observations on the biology of vaccinia. Am J Trop Med Hyg 1975;24:656--63.

* Additional information about MILVAX available at

What is already known on this topic?

Smallpox vaccination, which is conducted in the U.S. military, can result in autoinoculation and unintended transmission of vaccinia virus to others.

What is added by this report?

A vaccinia virus infection in a female patient resulted from digital vaginal contact with a recent military smallpox vaccinee.

What are the implications for public health practice?

Health-care providers caring for U.S. military personnel or their contacts should consider vaccinia virus infection in the differential diagnosis of clinically compatible genital lesions.

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