A Locally Transmitted Case of SARS-CoV-2 Infection in Taiwan

To the Editor: Since December 2019, an outbreak of infection with the novel coronavirus (SARS-CoV-2) has developed in Wuhan, China, and has spread to several countries, typically by travelers returning from China.^1,2 Of the 3 million Taiwanese persons who work in China, 2000 work in Wuhan, so the risk of imported SARS-CoV-2 infection to Taiwan from China is high. As of January 29, there were 7 confirmed imported cases of infection with SARS-CoV-2 to Taiwan. We identified a case of locally transmitted infection in Taiwan from a wife to her husband.

On January 25, 2020, a 52-year-old woman with a history of type 2 diabetes presented with fever to an emergency department in central Taiwan. She was admitted to the hospital because of suspicion of pneumonia associated with SARS-CoV-2 infection. She had lived in Wuhan from October 21, 2019, to January 20, 2020. She returned to Taiwan from Wuhan on January 20 on an airplane. On the same day, a throat swab was obtained from another passenger on that flight; that passenger was confirmed to have the first known imported case of SARS-CoV-2 infection in Taiwan when the swab was found to be positive for the virus on January 21.

Fever and myalgia developed in the woman on January 25, a total of 5 days after she returned to Taiwan from Wuhan. She reported that she did not have cough, dyspnea, chest pain, or diarrhea. Chest radiography showed diffuse infiltrates in the bilateral lower lungs (Figure 1A). Assays to detect influenza viruses and a respiratory panel to detect adenovirus, human rhinovirus, parainfluenza virus, respiratory syncytial virus, Bordetella pertussis, Chlamydia pneumoniae, and Mycoplasma pneumoniae were all negative. A throat swab was positive for SARS-CoV-2 on real-time reverse-transcription–polymerase-chain-reaction (RT-PCR) assays on January 27^3,4; this was the fifth confirmed imported case of Covid-19 (the illness caused by SARS-CoV-2 infection) in Taiwan.

Figure 1. Imaging of the Wife’s Chest.

Panel A shows diffuse infiltrates in the bilateral lower lungs on a radiograph obtained on day 1 (on admission), and Panel B shows progressive diffuse interstitial opacities and consolidation in the bilateral lower lung fields on a radiograph obtained on day 5 after admission.

On day 1 of hospitalization, the patient received supportive therapies, and oseltamivir and levofloxacin were added as empirical therapy on day 3 of hospitalization after SARS-CoV-2 was detected on RT-PCR. Cough, rhinorrhea, and sore throat developed on day 5, and chest radiography revealed progressive diffuse interstitial opacities and consolidation in the bilateral parahilar areas and lower lung fields (Figure 1B). She continued to receive supportive therapy with oseltamivir and levofloxacin, but she did not receive oxygen therapy. As of February 11, she remained hospitalized, but her vital signs were stable and she was not receiving oxygen therapy.

The patient’s 50-year-old husband is a music producer who works primarily at home in Taiwan. He reported that he had not traveled to any region where SARS-CoV-2 transmission was known to be occurring and that he had no known contacts with any person returning from such a region; this was confirmed by an investigation by the government health care unit in Taiwan. On January 21, he met his wife when she returned to Taiwan. They shared a bedroom and meals at home.

On January 25, the husband sought medical treatment at the same time as his wife. He presented only with rhinorrhea; he did not have fever, cough, dyspnea, chest pain, or diarrhea. He was admitted to the hospital because of concern regarding Covid-19, given his close contact with his wife. A complete blood count and chest radiography did not show any abnormalities. Assays for influenza viruses and a respiratory panel were negative, but SARS-CoV-2 was detected on RT-PCR on January 28.

The husband’s symptoms developed on the same day as those of his wife, January 25. This suggests transmission shortly after his wife returned to Taiwan. During the hospital stay, he had rhinorrhea, and myalgia developed on January 27, but he did not have fever (see Fig. S1 in the Supplementary Appendix, available with the full text of this letter at NEJM.org). He received supportive therapy without any antiviral agents or antibiotics. As of February 11, he remained hospitalized, but his vital signs were stable and he was not receiving oxygen therapy.

Local transmission of SARS-CoV-2 infection occurred in this couple in Taiwan. So far, no secondary case from this couple has been identified.

This letter was published on February 12, 2020, at NEJM.org.