NEW YORK ¨C Craig Spencer, the New York City doctor who contracted Ebola while treating patients in Guinea, will be released tomorrow from Bellevue Hospital Center in Manhattan and is free of the virus.

¡°Dr. Spencer poses no public health risk,¡± the city¡¯s Health and Hospitals Corporation said in an email. He received a ¡°rigorous course of treatment and testing,¡± the agency said.

Spencer, 33, has served as a volunteer with Doctors Without Borders, an aid group that has sent medical professionals to fight the outbreak at its West African source. He fell ill on Oct. 23, six days after returning to New York from the outbreak zone, and was rushed to Bellevue and put in a special isolation unit.

About nine hours later, officials confirmed the infection. His treatment included brincidofovir, an experimental drug made by Chimerix Inc., as well as a blood transfusion from another Ebola survivor, which can boost virus-fighting antibodies in a patient.

Spencer¡¯s fiancee remains under quarantine at home until Nov. 14. Two of Spencer¡¯s friends who had been quarantined have since been released.

Thomas Eric Duncan, the Liberian national who died from Ebola on Oct. 8 in Dallas, is the only death from the disease in the U.S. Seven other Ebola patients treated at various American hospitals have survived. They include two Dallas nurses infected by Duncan, several American aid workers and a TV cameraman who got sick in West Africa and were flown home.

The Ebola outbreak, concentrated in Liberia, Guinea and Sierra Leone, has infected more than 13,000 worldwide and killed more than 4,800, according to the World Health Organization. There is no approved cure for the disease. Current standard care involves supporting the patient and using antibiotics to fight off secondary infections.

Bellevue, the oldest continuously operating hospital in the U.S., is one of eight hospitals designated by New York State as go-to centers to care for a potential Ebola patient. The Midtown facility had upgraded its infectious disease unit in the weeks before Spencer was admitted in preparation for a case like his.

The isolation rooms were fitted with separate air management systems and a power supply that permits the use of specialized life-support equipment, and a new laboratory was built so blood samples wouldn¡¯t have to be transported to the hospital¡¯s regular laboratory.

Spencer had ventured around the city soon before he was driven to the hospital with Ebola symptoms. He rode the subway, ate at a meatball restaurant and visited a bowling alley. In the days after he went to Bellevue, the U.S. Centers for Disease Control and Prevention toughened its guidelines for people with direct exposure to the virus, saying they should be isolated in their homes for 21 days.