Updated Oct. 17 at 7:23 p.m.

After local, state and federal health officials scrambled to address a possible case of Ebola, they found that the disease has not yet spread to the Elm City.

Initial test results for a Yale graduate student suspected of having Ebola have come back negative, Yale-New Haven Hospital announced shortly after 5 p.m. Thursday. The patient, one of the two graduate students who recently returned from researching the Ebola outbreak in Liberia, was admitted to YNHH with “Ebola-like symptoms” on Wednesday night. Both graduate students are currently in isolation. A subsequent press release from the Connecticut Department of Public Health at 5:44 p.m. confirmed the negative result, adding that further test results were expected from the Centers for Disease Control and Prevention the following day.

Early Friday evening, University President Peter Salovey announced in an email to the Yale community that YNHH has received a second confirmation from the CDC that the graduate student does not have Ebola. But he added that the students will remain in isolation according state guidelines.

“Despite this welcome outcome, both of the students who traveled recently to Liberia will continue to abide by the quarantine guidelines established by the State of Connecticut,” Salovey said.

State and hospital officials have declined to comment as to the identity of the graduate student.

Dana Marnane, the director of public relations and communications for the hospital, said YNHH will continue to monitor the patient while waiting for official confirmation of the test result from the CDC.

While University administrators have insisted that the patient did not have contact with the disease, Yale Medical School Dean Robert Alpern said that the patient “did have contact with one person who eventually developed Ebola.”

A source familiar with the patient’s travel activities said the patient came in direct contact with NBC cameraman Ashoka Mupko, who was diagnosed with Ebola on Oct. 1. According to the source, the patient said that contact came the day before Mupko developed symptoms. NBC declined to comment on the matter.

Ebola is currently believed to only be transmitted when a person is symptomatic.

The patient hospitalized Wednesday evening traveled to Liberia with another graduate student. Initially, both had planned to quarantine themselves for 21 days — the incubation period for Ebola — upon their return to the United States earlier this week. Late last week, however, that decision was reversed when University physicians and administrators decided that a quarantine was unnecessary.

But on Thursday, the decision was reversed again. Both students will be in quarantine for 21 days, Salovey said in the second of two emails sent to the University Thursday.

“[The doctoral students] have reported that they were not in contact with Ebola patients or caregivers in Liberia, that they carefully followed recommended travel and hygiene precautions during their stay in the country and that they have continued to do so since their return,” Salovey said in the first email.

The administration, he said, will continue to update the Yale community as it receives more information.

Earlier in the afternoon, Mark D’Antonio, a spokesperson for the hospital, said the patient is in stable, good condition.

The patient contacted Yale Health on Wednesday night reporting symptoms of Ebola. Yale Health arranged for the patient to be transported to YNHH by American Medical Response — privately contracted first responders — at approximately 9 p.m., said Edward Badamo, operations manager at American Medical Response.

The patient, Badamo said, was transported to YNHH in accordance with isolation procedures. The back of the ambulance was covered in plastic, the ambulance crew wore Tyvek suits and the patient was also placed in a Tyvek suit, Badamo said.

On Thursday morning, the hospital released a statement saying that no diagnosis had been confirmed or ruled out. By that time, the patient had been put into an isolation room with negative pressure, ensuring that air flows into the room, rather than out of it.

At a 12:30 p.m. press conference on Thursday — which included statements from YNHH President Richard D’Aquila, YNHH Chief Medical Officer Thomas Balcezak and New Haven Mayor Toni Harp — D’Aquila said that the patient was in isolation and was being monitored by a clinical team. The hospital, he said, was working with local, state and federal officials on the issue.

“We feel we are well prepared to handle an event like this,” D’Aquila said. “We have been preparing for the potential of an Ebola patient for weeks.”

At the press conference, hospital administrators said that a sample from the patient was sent to a state laboratory in Massachusetts for testing.

The CDC directed the hospital to send the sample to a lab in Massachusetts, D’Antonio added.

Yale School of Public Health Dean Paul Cleary said he could not comment on the identity of the patient, as did hospital administrators at the press conference. University Chief Communications Officer Elizabeth Stauderman ’83 LAW ’04 also declined to comment Thursday morning.

The Yale researchers were originally slated to return from Liberia on Oct. 4, but their return home was delayed by a week for unspecified reasons.

At a Thursday afternoon press conference on the potential Ebola case, Gov. Dannel Malloy confirmed that the state will take advantage of the state of public health emergency declared last week. The executive order granted Department of Public Health Commissioner Jewel Mullen the power to quarantine suspected cases and carry out the appropriate isolation procedures. Yale initiated the current quarantine without prompting from the state.

Malloy also announced the formation of a command team in response to the potential case, led by Mullen and comprised of senior officials from the governor’s office, the DPH, the Department of Emergency Services and other state departments. He also demanded that every hospital perform a drill within the next week to ensure preparedness of hospital staff and first responders.

“We must go above and beyond what the CDC recommends,” Malloy said.

Malloy added he hoped the press conference would alleviate any potential hysteria surrounding news of the patient.

Beyond Salovey’s email, it was not clear on Thursday what, if any, additional steps the University was taking to prepare for the possibility of a positive test result. University Director of Emergency Management Maria Bouffard did not respond to repeated requests for comment.

While University administrators and public health officials were speaking with local media at YNHH, CDC director Thomas Frieden testified before a Congressional House panel about his organization’s response to the Ebola outbreak. Frieden defended the CDC’s actions, calling its measures of screening and tracking down potential patients as “tried and true.” There are no shortcuts in fighting Ebola, he added, and the CDC has mobilized teams to aid affected hospitals.

Lawrence Grotheer, director of communications at the Mayor’s office, said both YNHH and American Medical Response followed measures surpassing the CDC recommendations, and New Haven residents are at minimal risk of exposure to Ebola if they have not recently been in West Africa.

Over the past month, there have been four confirmed cases of Ebola within the United States.