Neonatal Monkeypox Virus Infection | NEJM

Neonatal Monkeypox Virus Infection | NEJM

To the Editor:

The ongoing monkeypox outbreak was recently declared to be a Public Health Emergency of International Concern by the World Health Organization.1 Young children are at risk for severe disease; therefore, early recognition and prompt treatment are important.2

Figure 1. Figure 1. Monkeypox Skin Lesions in a Newborn Infant.

Shown are monkeypox skin lesions on the hands and feet of a newborn infant. Visible lesions range from vesicles to pustules, and lesions that were beginning to form scabs are also shown. Photographs were obtained on day 5 after the onset of rash.

We report a case of perinatally acquired monkeypox virus infection and adenovirus coinfection in a 10-day-old infant. After the infant’s uneventful birth in late April 2022, a rash developed on day 9 of life. The rash was initially vesicular, starting on the palms and soles and subsequently spreading to the face and trunk, and gradually became pustular (Figure 1). Nine days before the birth, the infant’s father had had a febrile illness, followed by a widespread rash; the rash resolved before the infant’s birth. Four days after the infant’s delivery, a similar rash developed in the mother. The family lived in the United Kingdom, and there was no history of travel to Africa or of contact with any travelers.

The infant was transferred to the regional pediatric intensive care unit on day 15 of life owing to evolving hypoxemic respiratory failure (Fig. S1 in the Supplementary Appendix, available with the full text of this letter at A number of diagnoses (neonatal varicella, herpes simplex virus infection, coxsackievirus or enterovirus infection, staphylococcal skin infection, scabies, syphilis, and gonorrhea) were considered. The presence of axillary lymphadenopathy, the nature of the skin lesions, and the atypical timeline of intrafamilial infection aroused concern regarding human monkeypox. Polymerase-chain-reaction testing of blood, urine, vesicular-fluid, and throat-swab samples obtained from the infant and mother led to a diagnosis of monkeypox virus infection (clade IIb). Adenovirus was also identified in the infant’s respiratory secretions and blood. The infant’s condition worsened, and invasive ventilation was initiated. A 2-week course of enteral tecovirimat (at a dose of 50 mg twice a day) was commenced in combination with intravenous cidofovir. After 4 weeks in intensive care, including 14 days of invasive ventilation, the infant recovered and was discharged home. The timeline of intrafamilial infection and test results is shown in Figure S2.

Reports of neonatal monkeypox virus infection are rare.3 This was a case of neonatal monkeypox virus infection after peripartum transmission within a family cluster; transplacental transmission could not be ruled out.4 Because this was a single case, it is not possible to attribute the clinical illness to either pathogen (monkeypox virus or adenovirus) directly, nor is it possible to attribute the improvement in the infant’s clinical condition to the use of tecovirimat or cidofovir.5 Monkeypox virus infection should be considered in the differential diagnosis of a neonatal vesicular rash.

Padmanabhan Ramnarayan, M.D.
Imperial College London, London, United Kingdom
[email protected]

Rebecca Mitting, M.B., B.S.
Imperial College Healthcare NHS Trust, London, United Kingdom

Elizabeth Whittaker, Ph.D.
Imperial College London, London, United Kingdom

Maria Marcolin, M.R.C.P.C.H.
Ciara O’Regan, M.R.C.P.C.H.
Ruchi Sinha, M.R.C.P.C.H.
Aisleen Bennett, Ph.D.
Moustafa Moustafa, M.R.C.P.C.H.
Neil Tickner, M.Pharm.
Mark Gilchrist, M.Sc.
Imperial College Healthcare NHS Trust, London, United Kingdom

Anthony Kershaw, M.R.C.P.C.H.
London Northwest University Healthcare NHS Trust, London, United Kingdom

Tommy Rampling, D.Phil.
U.K. Health Security Agency, London, United Kingdom

Disclosure forms provided by the authors are available with the full text of this letter at

This letter was published on October 12, 2022, at

A list of the members of the NHS England High Consequence Infectious Diseases (Airborne) Network is provided in the Supplementary Appendix, available at

5 References

  • 1. World Health Organization. Multi-country outbreak of monkeypox, external situation report #3 — 10 August 2022 (–external-situation-report–3—10-august-2022).

  • 2. Meyer H, Perrichot M, Stemmler M, et al. Outbreaks of disease suspected of being due to human monkeypox virus infection in the Democratic Republic of Congo in 2001. J Clin Microbiol 2002;40:2919-2921.

  • 3. Yinka-Ogunleye A, Aruna O, Dalhat M, et al. Outbreak of human monkeypox in Nigeria in 2017–18: a clinical and epidemiological report. Lancet Infect Dis 2019;19:872-879.

  • 4. Mbala PK, Huggins JW, Riu-Rovira T, et al. Maternal and fetal outcomes among pregnant women with human monkeypox infection in the Democratic Republic of Congo. J Infect Dis 2017;216:824-828.

  • 5. Sherwat A, Brooks JT, Birnkrant D, Kim P. Tecovirimat and the treatment of monkeypox — past, present, and future considerations. N Engl J Med 2022;387:579-581.

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