Epidemiologic Risk Factors to Consider when Evaluating a Person for Exposure to Ebola Virus

The following epidemiologic risk factors should be considered when evaluating a person for Ebola virus disease (Ebola), classifying contacts, or considering public health actions such as monitoring and movement restrictions based on exposure.

1. High risk includes any of the following:
   • Percutaneous (e.g., needle stick) or mucous membrane exposure to blood or body fluids of a person with Ebola while the person was symptomatic
   • Exposure to the blood or body fluids (including but not limited to feces, saliva, sweat, urine, vomit, and semen) of a person with Ebola while the person was symptomatic without appropriate personal protective equipment (PPE)
   • Processing blood or body fluids of a person with Ebola while the person was symptomatic without appropriate PPE or standard biosafety precautions
   • Direct contact with a dead body without appropriate PPE in a country with widespread Ebola virus transmission
   • Having lived in the immediate household and provided direct care to a person with Ebola while the person was symptomatic
2. Some risk includes any of the following:
   • In countries with widespread Ebola virus transmission:
     • direct contact while using appropriate PPE with a person with Ebola while the person was symptomatic or with the person's body fluids
     • any direct patient care in other healthcare settings
   • Close contact in households, healthcare facilities, or community settings with a person with Ebola while the person was symptomatic
     • Close contact is defined as being for a prolonged period of time while not wearing appropriate PPE within approximately 3 feet (1 meter) of a person with Ebola while the person was symptomatic
3. Low (but not zero) risk includes any of the following:
   • Having been in a country with widespread Ebola virus transmission within the past 21 days and having had no known exposures
   • Having brief direct contact (e.g., shaking hands) while not wearing appropriate PPE, with a person with Ebola while the person was in the early stage of disease
   • Brief proximity, such as being in the same room for a brief period of time, with a person with Ebola while the person was symptomatic
   • In countries without widespread Ebola virus transmission: direct contact while using appropriate PPE with a person with Ebola while the person was symptomatic
   • Traveled on an aircraft with a person with Ebola while the person was symptomatic
4. No identifiable risk includes:
   • Contact with an asymptomatic person who had contact with person with Ebola
   • Contact with a person with Ebola before the person developed symptoms
   • Having been more than 21 days previously in a country with widespread Ebola virus transmission
   • Having been in a country without widespread Ebola virus transmission and not having any other exposures as defined above
   • Aircraft or ship crew members who remain on or in the immediate vicinity of the conveyance and have no direct contact with anyone from the community during the entire time that the conveyance is present in a country with widespread Ebola virus transmission