On May 4, 2003, a US Army soldier received primary smallpox vaccination
and experienced a primary uptake reaction at the inoculation site on days
6 through 8. The vaccinee reported observing all of the standard precautions
to avoid household spread. In mid May, his breastfeeding wife developed vesicles
on both areolas. On May 29, their infant daughter developed a papule on her
philtrum. Contact vaccinia was confirmed by positive polymerase chain reaction
and culture for vaccinia of both the maternal and infant lesions. This is
the first documented case of inadvertent contact vaccinia transmission from
a mother to her infant through direct skin-to-skin and skin–to–mucous
membrane contact while breastfeeding. The mechanism of transfer from the vaccinee
to the spouse is uncertain. This report demonstrates that breastfeeding infants
living in close contact with smallpox vaccinees are at potential risk for
contact vaccinia, even if the vaccinee is not the breastfeeding mother, and
highlights the need for special precautions to prevent secondary transfer
to breastfeeding mothers.
In response to recent concerns that smallpox virus might be used as
a biological weapon against military or civilian targets, the US Department
of Health and Human Services (DHHS) and the US Department of Defense (DOD)
implemented large-scale smallpox immunization programs, including vaccination
of volunteer health care workers who may be first responders or secondary
providers for smallpox patients and all military personnel prior to deployment
to an area where smallpox might be used as a weapon. More recently, a monkeypox
outbreak in the midwestern United States led the Centers for Disease Control
and Prevention (CDC) to issue interim guidelines for vaccinia administration
to protect individuals at risk of that infection.1
The United States discontinued routine childhood smallpox immunization
in 1971 and routine immunization of health care workers in 1976. With the
renewed smallpox immunization program, many health care workers have confronted
vaccinia reactions for the first time. Although recommendations have been
made to minimize complications such as inadvertent inoculation, risk of household
transmission remains a concern, and risk estimates are currently based primarily
on historical information. Such information has limitations because it is
derived from surveillance studies that likely underreported mild reactions;
also, it applies to a population with different levels of baseline immunity.2,3 We report a recent case of tertiary
contact vaccinia in the infant of a breastfeeding wife of a primarily vaccinated
soldier. This case highlights the potential for inadvertent household spread
and the importance of recognition of this complication.
On May 4, 2003, a 27-year-old soldier received primary smallpox vaccination;
he experienced a primary reaction (local reaction papule on an erythematous
base consistent with vaccine uptake on days 6 to 8 after immunization, accompanied
by headache and lymphadenopathy for several days, but no significant pruritus).
In accordance with established educational protocols, he had received standardized
instruction on the prevention of autoinoculation and contact transmission
at the time of vaccination. In addition to hand washing and keeping the site
covered with a gauze nonocclusive dressing, he was also told to limit contact
with his 5-month-old breastfeeding daughter. The vaccinee slept in the same
bed with his 27-year-old wife, wearing a short-sleeved shirt with bandages
in place. He denied any drainage from the dressing or any significant pruritus.
Neither the vaccinee nor his spouse recalled the dressing ever falling off
while in bed. After bathing, he dried the vaccination site with tissue that
he disposed of in a trash receptacle. He placed bath towels used to dry himself
in a laundry container, rolling the towels so that the area that dried his
arm was rolled to the inside. His wife did handle all the laundry, including
bed linen and towels. She denied seeing any drainage on either clothing or
linens or having any direct contact with his vaccination site.
In mid May, the wife developed painful vesicular skin lesions on both
areolas. She did not recognize that the lesions might be due to a contact
infection with vaccinia, so she continued to breastfeed the infant. She was
seen several times as an outpatient for this complaint, beginning on day 4
of the infection, and was treated for mastitis with nystatin, fluconazole,
and cephalexin, without improvement. On May 29, she ceased breastfeeding because
On May 29, the infant developed a papule on her philtrum, which progressed
to a papulo-vesicle-pustule and then formed a crust. On May 30, a similar
lesion developed on her left cheek. On June 2, the infant was taken to her
pediatrician, where she was noted to have an ulcer on the left lateral side
of her tongue in addition to the other 2 lesions. She also had a temperature
of 38.4°C but was otherwise healthy in appearance, with no other lesions.
The infant did not have a history of eczema, skin disease, or immunocompromise.
The only other family member, the infant's 4-year-old brother, did not have
any skin lesions. The infant was diagnosed with suspected contact vaccinia
and transferred to Madigan Army Medical Center, Tacoma, Wash, on June 2 for
further evaluation, observation, and treatment.
On admission, the infant was alert, afebrile, and in no distress. There
was no conjunctival injection or palpebral irritation or erythema. The 2 lesions
noted on her philtrum and left cheek had eschar formation, with the beginnings
of ulceration with mild surrounding erythema (Figure 1). Her tongue lesion was a small, white, shallow ulcer on
the left lateral aspect. There were no other skin lesions and the remainder
of her examination was unremarkable.
The clinical appearance of these lesions as well as the history were
all consistent with inadvertent localized vaccinia inoculation. Both initial
viral culture and polymerase chain reaction results for vaccinia were positive
from the infant's facial and tongue lesions as well as from the maternal areolar
lesions. These results were confirmed when repeated with new specimens at
the Madigan Army Medical Center Laboratory. Cultures were negative for herpes
simplex virus. To prevent further inadvertent inoculation, the infant was
placed in isolation, her lesions were covered with film dressings, eye goggles
were placed, and soft restraints were used while the infant was awake and
not in the mother's arms. An ophthalmologist was consulted and confirmed no
evidence of ocular vaccinia.
Treatment of the infant with vaccinia immune globulin (VIG), intravenous
VIG (IV-VIG), or cidofovir was discussed, but the infant did not meet any
of the CDC criteria for treatment of a vaccinia complication.4 The
infant was monitored closely for spread or other complications. By day 7 after
onset of signs, the oral lesion had become a small ulcer and the lesion on
the cheek was entirely crusted. However, the lesion on the philtrum continued
to weep, which was attributed to occlusion with the dressing and excessive
moisture. To facilitate healing, the lesion was aired 2 to 3 hours a day while
exposed to heat lamps. The initial bacterial culture of the philtrum lesion
grew methicillin-sensitive Staphylococcus aureus, which
was treated with topical mupirocin calcium (Bactroban). By postonset day 13,
all of the infant's lesions were crusted over completely, and there was no
autoinoculated spread to other sites. The infant remained afebrile and alert
throughout the hospital course. She was discharged to home after a 12-day
stay. At follow-up on July 7, 2003, her lesions had entirely resolved with
no significant scarring.
The maternal breast lesions healed slowly, which was attributed to excessive
moisture in the area. The mother also did not meet criteria for VIG, IV-VIG,
or cidofovir therapy. She was told to air-dry the lesions with a blow-dryer
3 times a day, which improved crusting. By the time of discharge, approximately
28 days into her course, the lesions on the mother's areolae were no longer
painful and mainly crusted. Prior to discharge, the mother received further
education on prevention of household transmission to her older child. No further
spread was recorded from either patient, and the maternal lesions had entirely
healed by July 7, 2003. Both cases of contact vaccinia were reported to the
Military Vaccine Agency of the Office of the Surgeon General and the Vaccine
Adverse Events Reporting System.
We report the first documented case of inadvertent contact vaccinia
transmission from mother to infant through direct skin-to-skin and skin–to–mucous
membrane contact while breastfeeding. This incident represents transmission
of vaccinia from a primary vaccinee to 2 household contacts. Because of the
timing of onset of the lesions and the plausible route of spread from infant
contact with maternal breast, we believe that contact vaccinia in the infant
occurred after secondary transmission from the vaccinee to his spouse, followed
by tertiary transmission from the spouse to the infant. The mechanism of transfer
from the vaccinee to his spouse is uncertain and may have been from fomites
such as bed linens or clothing. Although the vaccinee's spouse denied any
direct contact of her breasts with the dressing site, this possibility cannot
be completely excluded. Another possibility is that she failed to wash her
hands between handling the laundry and initiating breastfeeding. She could
not recall if she always washed her hands prior to breastfeeding.
We encountered several dilemmas in caring for the infant. Although she
ultimately did not meet criteria for treatment of a vaccinia complication,
none of the currently available therapies are licensed for use in children.
The pharmacodynamics of cidofovir in children are unknown. These drawbacks
to potential therapy underscore the primary importance of prevention. We also
found that because of the location of the infant's lesions, it was difficult
to keep them covered to prevent autoinoculation. The moist environment of
both patients' lesions also delayed crust formation. Using a heat source local
to the areas helped to enhance the crusting.
The CDC recommends against smallpox vaccination of breastfeeding mothers.5 However, there is no recommendation against vaccination
of other family members when there is a breastfeeding infant in the home.
To the contrary, the CDC smallpox fact sheet "Smallpox Vaccination Information
for Women Who Are Pregnant or Breastfeeding" states that it is safe for a
woman to breastfeed her baby if a close contact received smallpox vaccine,
provided that the vaccinee follows the standard hand-washing and site protection
precautions. These precautions are described by the CDC as remembering "to
wash their hands with soap and warm water after direct contact with the vaccination
site, or anything that has touched the vaccination site (bandages, clothing,
towels, bedding, etc)."6 Despite reported adherence
to these guidelines by both parents, tertiary transmission to the infant occurred.
Additionally, neither the mother nor her physician recognized inadvertent
inoculation of her breasts, which led to a delay in diagnosis and continued
breastfeeding of the infant.
Historically, the rate of contact vaccinia household transmission has
been low. For example, in a recent review of published reports from 1931 to
1981 of secondary household transmission of vaccinia, Sepkowitz3 provides
details on 27 cases, including fatalities. An identified risk factor in these
cases was sharing close quarters with a vaccinee with sustained, intimate
contact. In 1 case, an 18-year-old female military vaccinee inadvertently
transmitted vaccinia to an 18-year-old female neighbor, who developed facial
lesions. Two contacts of this neighbor, one who had kissed her and another
who had "had contact" with her, also developed facial lesions. Although such
incidents may have been underreported in the past, these 2 cases constitute
the only previously published report of tertiary inadvertent transmission.
Despite concerns that contact vaccinia might occur more frequently today
because of more immunocompromised hosts and primary vaccinees, recent data
from the DOD and DHHS vaccination programs support historical data that the
risk of contact vaccinia remains low. Surveillance studies conducted in the
United States by the CDC in the 1960s estimated a contact vaccinia risk of
2 to 6 per 100 000 primary vaccinations.7,8 In
these studies, transmission required close contact with a vaccine recipient,
usually within the home. Between December 2002 and January 12, 2004, the DOD
vaccinated 548 438 people against smallpox. From this cohort, 29 suspected
cases of contact vaccinia were identified (18 confirmed by polymerase chain
reaction), for an incidence of 5.3 contact transfers per 100 000. Only
2 of the cases reported, including the case reported herein, occurred in children
(Col John D. Grabenstein, deputy director, Military Vaccine Agency, US Army
Medical Command, Office of the Surgeon General, written communication, January
15, 2004). Additionally, between January 24 and June 20, 2003, 37 802
civilian health care and public health workers were vaccinated with no reported
cases of contact vaccinia.9
This report demonstrates that breastfeeding infants living in close
contact with smallpox vaccinees are at potential risk for contact vaccinia,
even if the vaccinee is not the breastfeeding mother, and highlights the need
for special precautions to prevent secondary transfer to breastfeeding mothers.
We recommend that the CDC revise its guidelines to state that vaccine recipients
should not sleep in the same bed as a breastfeeding mother, that vaccine recipients
handle their own laundry, and that breastfeeding mothers in these households
be reminded to wash their hands prior to breastfeeding. Clinicians should
be alert to the possibility of contact vaccinia in any family member of a
smallpox vaccine recipient presenting with a pustular or vesicular rash. Breastfeeding
women living with vaccine recipients should be educated about the appearance
of contact vaccinia lesions and told to seek medical attention if they develop
any skin lesions.6 Breastfeeding should be
temporarily stopped until such lesions can be evaluated.
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