New York City has its first case of Ebola.
A health care worker who was rushed to New York City’s Bellevue Hospital Thursday has reportedly tested positive for the virus. The Center for Disease Control and Prevention is conducting its own test to verify the case.
Health care worker Craig Spencer, 33, had returned last week to the U.S. from Guinea, one of the three West African countries hardest hit by the Ebola outbreak. He is now being treated in an isolation unit at Bellevue Hospital, Mayor Bill de Blasio told a press conference late Thursday.
“We want to state at the outset that there is no reason for New Yorkers to be alarmed,” de Blasio said. “The Health Department has a team of disease detective who have been at work tracing all of the patient’s contacts and we are prepared to quarantine contacts as necessary.”
Spencer is understood to have traveled on the A, 1 and L trains and visited a bowling alley called “The Gutter” before starting to display symptoms. Ebola victims are only transmit the virus after they become symptomatic, however.
The New York Times quoted city health commissioner Dr. Mary Bassett as saying that Spencer “did not have a stage of disease that creates a risk of contagiousness on the subway.”
“We consider it extremely unlikely, the probability being close to nil, that there will be any problem related to his taking the subway system,” she added.
In contrast to nurse Amber Vinson, who was allowed by the CDC to board a commercial flight despite already having a fever, Spencer did not leave his apartment after reporting symptoms and was isolated within two hours of reporting them, according to the NYT.
TIME reported that New York City previously designated Bellevue Hospital to receive any Ebola patients that should enter the city. Bellevue has also been preparing to accept Ebola patients from other hospitals if need be. New York City hospitals in general have been preparing and drilling for the possibility of a patient with Ebola since August, most recently by holding an an Ebola education session for over 5,000 local health care workers on Tuesday.
The World Health Organization said earlier this week that the number of cases in the outbreak, which started in August, has now risen to just under 10,000, with roughly half ending in death so far. The disease is ravaging Sierra Leone and Liberia, and is spreading in Guinea, but it has been stopped from spreading in Nigeria and Senegal, the WHO says.
MORE ON THIS STORY via TIME.com: How Worried Should NYC Be?
Can You Get Ebola From Subway Poles and Bowling Balls?