Image by Victor Tangermann

The Centers for Disease Control and Prevention (CDC) confirmed the first person-to-person transmission of the coronavirus in the United States, CNBC reports — the first reported direct infection in North America.

The newly-infected patient is the husband of a woman who took a flight back from Wuhan, China — the epicenter of the outbreak — inadvertently bringing the virus with her.

The transmission made the US at least the fourth country where person-to-person transmission of the deadly virus has been confirmed, after Germany, Japan, Vietnam, and Taiwan, The Verge reports. As of Wednesday, 165 patients are under investigation in the US, according to the CDC.

In total, more than seven thousand cases have been confirmed, the majority in mainland China, according to The New York Times. The virus, also known as 2019-nCoV, has claimed the lives of 171 people.

“Moving forward, we can expect to see more cases, and more cases means more potential for person-to-person spread,” Nancy Messonnier, director of the National Center for Immunization and Respiratory Diseases, told CNBC.