Updated 10:20 a.m.

Two graduate student researchers at the Yale School of Public Health preparing to return from Liberia have agreed to sequester themselves for three weeks as a precautionary measure in case they have contracted Ebola.

The news was announced to faculty, students and staff at the Yale School of Public Health in aThursday email from YSPH Dean Paul Cleary.

The researchers, whose names have not yet been released, are Epidemiology of Microbial Diseases doctoral students who left for the epidemic-stricken country on Sept. 16. They were helping set up a computer system for the Liberian Ministry of Health to monitor the West African Ebola outbreak and track contact tracing, according to the email.

The email also noted that the students had no direct contact with Ebola patients and are currently asymptomatic.

“Understandably, there is potential for concern from faculty, students and staff that appropriate protocols and recommendations are being followed,” Cleary’s email stated. “I assure you that YSPH and Yale have taken extensive precautions to ensure the safety of the researchers as well as that of the Yale community.”

The researchers will return from Liberia Saturday Oct. 4 and, upon arrival, call Yale Health to describe their state of health.

Before leaving Liberia, the two students observed travel procedures implemented after the epidemic began. These procedures included notifying the United States military and the Centers for Disease Control (CDC) of their return.

Cleary said the researchers’ preventative measures against Ebola have even extended beyond what is required by the CDC or urged by YSPH.

“The researchers volunteered to stay away from their office because of concerns raised by some staff; even though national guidelines do not suggest such an action,” Clearly said. “I did not ask them to do that.”

Director of the Global Health Initiative and Branford Master Elizabeth Bradley said the doctoral students volunteered to go to Liberia for their research. Their travel was approved by Cleary and supervising faculty in consultation with Yale Health.

Ebola cannot be transmitted through the air, but only through direct contact with bodily fluids, the email emphasized.

“It’s a good thing not to alarm people,” Bradley said. “All of the precautions have been followed according to the CDC’s guidelines. There are a lot of people in the military and public health volunteering all the time, and as long as precautions are followed — but they have to be followed exactly — everything will be okay.”

The news comes a week after Yale Health Director Paul Genecin and University Provost Ben Polak sent out a joint email announcing restrictions on travel to Guinea, Liberia, Sierra Leone and Nigeria.

In a Thursday night email to the News, Yale School of Medicine Dean Robert Alpern said in order to care for sick patients, it is sometimes necessary for healthcare professionals to put themselves in danger.

“The key is to act intelligently, adopt appropriate precautions, plan in advance and be careful,” Alpern said. “It appears that the School of Public Health has done this in this case.”

The 2014 Ebola outbreak has caused one-third of all deaths attributed to the virus since 1976, when it first emerged. According to the CDC, Ebola has so far claimed over 3,300 lives and infected over 7,100 people. On Tuesday, a patient in Texas became the first diagnosed Ebola case in the United States.

YSPH Professor Richard Skolnik ’72 said he is glad to see nations around the world responding so vigorously to the Ebola outbreak. But he added that there is still need for further action in West Africa.

“I sincerely hope that the pace and scale of global assistance for addressing the epidemic will be enhanced dramatically,” Skolnik said. “I also hope that this assistance will be led in a clear and coordinated way at every level. If not, I fear that the outbreak will stay ahead of these efforts to control it for a long time to come.”

According to the World Health Organization, patient zero of the most recent epidemic was a two-year-old Guinean boy who died on Dec. 28, 2013.