10/06/2014 03:01 EDT | Updated 12/06/2014 05:59 EST

Ebola update: Dallas officials give news conference

Officials in Dallas are providing an update on their investigation and containment processes in relation to the first Ebola case diagnosed in the U.S.

Dallas Ebola patient Thomas Eric Duncan remains in critical condition. 

A spokeswoman for Texas Health Presbyterian Hospital in Dallas said on Monday that Duncan is receiving an experimental drug for the disease. The drug, called brincidofovir, was developed by Chimerix Inc.

Duncan became ill after arriving in Texas from Liberia two weeks ago, heightening concerns that the worst Ebola epidemic on record could spread from West Africa, where it began in March.

Health officials were closely monitoring 10 people who had contact with Duncan and are considered at greatest risk. Another 38 people who potentially had contact with Duncan are also being tracked.

Also on Monday, a private plane carrying Ashoka Mukpo, a freelance cameraman for NBC News who contracted Ebola in Liberia, landed in Omaha en route to the Nebraska Medical Center, NBC reported. 

The virus that causes Ebola is not airborne and can only be spread through direct contact with the bodily fluids — blood, sweat, vomit, feces, urine, saliva or semen — of an infected person who is showing symptoms.

It has killed more than 3,400 people since it began in West Africa in December and has now begun spreading faster, infecting almost 7,500 people so far.