The two public health graduate students researching Ebola in Liberia since Sept. 16 will remain there for the foreseeable future.

The researchers, who were supposed to return to New Haven this past Saturday, have been advising the Liberian Ministry of Health on computer systems that monitor and model the Ebola outbreak, according to a Thursday email from Yale School of Public Health Dean Paul Cleary. Last Thursday, Cleary announced in an email to the YSPH community that the researchers were scheduled to return to the United States on Oct. 4. But in a Monday email to the News, Yale Medicine and Health Sciences spokesperson Karen Peart said that the graduate students are still in Liberia.

Peart said no specific return date has been determined but Yale officials are in regular contact with the students. She did not say why the researchers did not return as originally scheduled.

“We want to reiterate that the students will continue to follow all [Centers for Disease Control] travel guidelines to assure their safety and that of their colleagues at Yale and of the public,” Peart said in a Monday email to the News.

Peart would not disclose the names of the students.

As of Cleary’s Thursday email, the students were planning to sequester themselves for 21 days — the incubation period for Ebola — following their return to the U.S.

Yale Health Director Paul Genecin said the condition of an individual returning from an epidemic-stricken country determines where they are quarantined. Patients who have been exposed to the virus or lived in areas where the virus is prevalent, but have no symptoms, will often be sequestered in their home, he said. Meanwhile, he added, those who are known to be infected will be put in isolation at a hospital and cared for by doctors wearing protective clothing.

In the possibility of an Ebola outbreak, Yale’s emergency preparedness group, in conjunction with Yale Health, has a plan for epidemics and outbreak, Genecin said. He added that there is a tremendous amount of communication within the University, as well as with the Centers for Disease Control and city and state health officials.

“I think that saying that the world is safe isn’t quite right,” Genecin said. “Saying that we are prepared to deal rationally and appropriately in a guideline-driven way is a better way to put it.”

Audrey Odom, an assistant professor at Washington University in St. Louis’s Center for Global Health and Infectious Diseases, said people should remember that Ebola is difficult to contract compared to most diseases.

Though Odom said it is not unlikely that a hospital worker will contract Ebola from a patient in the U.S., she does not think it will reach epidemic proportions.

Yale School of Medicine professor of epidemiology Gerald Friedland said Yale and New Haven are prepared to accommodate the medical situations of the two YSPH students when they return. He added that Yale-New Haven Hospital has devoted a significant amount of energy to prepare for the possibility of a patient with Ebola, similar to hospitals in larger cities, by disseminating information and holding educational conferences.

Friedland said public health officials have to balance the need to protect researchers’ individual rights with the need to protect public safety. He added that patients must be isolated in the most humane way possible.

Professor of Public Health Richard Skolnik ’72, who worked in Liberia for seven years, said despite the continuation of the epidemic in Western Africa, medical teams are doing admirable work. But he also noted that much more work needs to be done on the ground before the epidemic can be abated.

“Without a much more dramatic increase in assistance it is hard to see how the effort will be able to catch up with and finally get ahead of Ebola,” Skolnik wrote in a Monday afternoon email to the News.

Friedland said the basic infection control practices for Ebola include identifying all cases, treating the infected and tracing contact. He emphasized that these protocols can be easily handled in the U.S., where there are sufficient health infrastructure and resources. In contrast, African countries such as Liberia present a challenge because many are too unstable to effectively implement public health policies.

On Oct. 6, a nurse in Spain became the first person in the epidemic to be infected while outside of West Africa.