TABLE 1.

Summary of CDC and U.S. Department of Defense Ebola virus disease (Ebola) exposure risk categories

Exposure category	U.S. Department of Defense (October 10 and 31, 2014)	CDC (December 24, 2014)
High risk	Percutaneous (e.g., needle stick) or mucous membrane exposure to blood or body fluids of an Ebola patient	Percutaneous (e.g., needle stick) or mucous membrane exposure to blood or body fluids (including but not limited to feces, saliva, sweat, urine, vomit, and semen) from a person with Ebola while the person was symptomatic
	Direct skin contact to blood/body fluids	Direct contact without appropriate PPE with a person with Ebola while the person was symptomatic or the person’s body fluids
	Processing blood/body fluids of an Ebola patient without standard biosafety precautions	Laboratory processing of blood or body fluids from a person with Ebola while the person was symptomatic without appropriate PPE or standard biosafety precautions
	Direct contact with a dead body	Direct contact with a dead body without appropriate PPE in a country with widespread transmission or a country with cases in urban settings with uncertain control measures
		In countries with widespread transmission, having provided direct care in a household setting to a person with Ebola while the person was symptomatic
Some risk	Brief direct contact (e.g., shaking hands) with an Ebola patient	Direct contact while using appropriate PPE with a person with Ebola while the person was symptomatic or the person’s body fluids or being in the patient-care area of an Ebola treatment unit
		Any direct patient care in non-Ebola health care settings
	Household contact with an Ebola patient	Close contact in households, health care facilities, or community settings with a person with Ebola while the person was symptomatic
	Close contact (within 3 feet [1 meter] of an Ebola patient)	Close contact is defined as being within approximately 3 feet (1 meter) of a person with Ebola while the person was symptomatic for a prolonged period while not using appropriate PPE
	Prolonged period in an Ebola patient-care area
No known exposure	Not in the some-risk or high-risk exposure category	NA
Low (but not zero) risk	NA	Having been in a country with widespread transmission, a country with cases in urban settings with uncertain control measures, or a country with former widespread transmission and now established control measures and having had no known exposures
		Brief direct contact (e.g., shaking hands), while not using appropriate PPE, with a person with Ebola while the person was in the early stage of disease
		Brief proximity with a person with Ebola while the person was symptomatic, such as being in the same room (not the patient-care area of an Ebola treatment unit) for a brief period
		In countries other than those with widespread transmission, direct contact while using appropriate PPE with a person with Ebola while the person was symptomatic or the person’s body fluids or being in the patient-care area of an Ebola treatment unit
		Laboratory processing of blood or body fluids from a person with Ebola while the person was symptomatic while using appropriate PPE and standard biosafety precautions
		Having traveled on an airplane with a person with Ebola while the person was symptomatic and having had no identified some-risk or high-risk exposures
No identifiable risk	NA	Laboratory processing Ebola-containing specimens in a biosafety level 4 facility
		Any contact with an asymptomatic person who had potential exposure to Ebola virus
		Contact with a person with Ebola before the person developed symptoms
		Any potential exposure to Ebola virus that occurred more than 21 days previously
		Having been in a country with Ebola cases but without widespread transmission, cases in urban settings with uncertain control measures, or former widespread transmission and now established control measures, and not having had any other exposures
		Having remained on or in the immediate vicinity of an aircraft or ship during the entire time that the aircraft or ship was in a country with widespread transmission or a country with cases in urban settings with uncertain control measures, and having had no direct contact with anyone from the community
		Having had laboratory-confirmed Ebola and subsequently been determined by public health authorities to no longer be infectious (i.e., Ebola survivors)

Abbreviations: NA = not applicable; PPE = personal protective equipment.

^*Some-risk and high-risk exposure categories apply to persons who had the listed exposure during the preceding 21 days without wearing appropriate PPE.