To the Editor:

Zika virus (ZIKV), a mosquito-borne flavivirus, is transmitted by the Aedes aegypti mosquito. As of December 28, 2016, more than 4500 travel-associated cases of Zika virus infection have been reported in the United States; a higher number of cases occur in states with a high influx of international travel.1

Figure 1. Figure 1. Cutaneous Eruption in a Pregnant Woman with Locally Acquired Zika Virus Infection. Generalized erythematous macules and papules are shown on the abdomen (Panel A) and back (Panel B) of a pregnant woman with locally acquired Zika virus infection in the United States.

On July 7, 2016, a 23-year-old pregnant woman (gravida 3, para 0, abortus 2) presented at 23 weeks and 3 days of gestation (gestational age was estimated from the date of the last menstrual period and is consistent with ultrasonographic findings at week 10 of pregnancy) with a 3-day history of fever, widespread pruritic rash, and sore throat, which were followed by myalgias and joint pain 2 days later. The patient had not yet initiated routine prenatal care. Both the patient and her partner reported no travel outside the United States for the past 2 years. Findings from physical examination were pertinent for erythematous follicular macules and papules on the trunk and arms, scattered tender pink papules on the palms, and a few petechiae on the hard palate; neither conjunctivitis nor lymphadenopathy was present (Figure 1). Histopathological examination of lesional skin revealed a mild perivascular lymphocytic infiltration in the upper dermis, admixed with some neutrophils (Fig. S1 in the Supplementary Appendix, available with the full text of this letter at NEJM.org). ZIKV RNA was detected in both urine and serum specimens with the use of reverse-transcriptase polymerase chain reaction (RT-PCR) (initial urine and serum testing was performed on July 7, 2016). Findings from fetal ultrasonography performed on the day of presentation showed an estimated fetal weight of 644 g (53rd percentile), an estimated head circumference of 221 mm (63rd percentile), and normal intracranial anatomy. Fevers and rash subsided after the patient received 3 days of supportive care. Screening for measles, varicella, rubella, syphilis, Epstein–Barr virus, influenza, hepatitis B, hepatitis C, mumps, and dengue was unrevealing. Test results for liver and renal function were within normal limits. Positive RT-PCR results for ZIKV persisted for 2 weeks in urine samples and for 6 weeks in serum samples. Seroconversion by serum IgM occurred 1 week after presentation (initial IgM test on July 7, 2016, was negative) and remained positive through delivery (Table S1 in the Supplementary Appendix). Serial fetal ultrasonography revealed no abnormalities ante partum. A full-term infant weighing 2990 g was delivered vaginally. Neonatal ultrasonography and magnetic resonance imaging of the head showed a normal head size and intracranial anatomy, with no calcifications. The patient declined amniocentesis; therefore, in utero testing of the fetus was not performed. RT-PCR assay in placental tissue sample was negative for ZIKV, and the results from remaining neonatal laboratory testing revealed no evidence of ZIKV infection (Table S1 in the Supplementary Appendix).

This case has been confirmed by the Miami-Dade County Department of Health as the first non–travel-associated case of ZIKV infection in the United States. Medical providers on the front line should be aware of the constellation of symptoms in patients reporting travel to endemic areas, including areas in southern Florida, where other non–travel-associated cases have been confirmed.2

Lucy Chen, M.D.

Farhaan Hafeez, M.D.

Christine L. Curry, M.D., Ph.D.

George Elgart, M.D.

University of Miami, Miami, FL

[email protected]

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

This letter was published on January 11, 2017, at NEJM.org.