Assessing Viral Hemorrhagic Fever Risk in a Returning Traveler

CALM: Consider, Act, Laboratory, Monitor

The CALM algorithm is for use by Emergency Room clinicians in assessing a patient with signs, symptoms, and/or diagnostic findings concerning for a possible viral hemorrhagic fever (VHF). While there are many types of VHFs, all of which are rare, this algorithm covers the relatively more common types seen globally: Ebola virus, Marburg virus, Lassa virus, and Crimean-Congo Hemorrhagic Fever (CCHF) virus.

This algorithm is not intended to be a comprehensive guideline, and should be used in conjunction with your hospital’s established policies for managing suspect/confirmed VHFs.

Exposure history

  • In the past 21 days, has the patient experienced one or more of the following:
  • If the patient does not have any risk factors for Viral Hemorrhagic Fever, continue with usual triage and assess for other causes of fever common in a returning traveler, including: malaria, dengue fever, Zika, Chikungunya, schistosomiasis, and enteric fever.
    • Refer to the TOUR algorithm for assistance with assessing fever in a returning traveler that does not have any risk factors for Viral Hemorrhagic Fever.
    • Refer to the CDC Yellow Book for more information on these
  • Travel notices are designed to inform travelers and clinicians about current health issues related to specific destinations. These issues may arise from disease outbreaks, special events or gatherings or other conditions that may affect travelers’ health.
  • For any questions about current outbreaks of VHFs, please call the CDC’s Emergency Operations Center at 770-488-7100 or email

Signs and Symptoms

  • Does the patient have signs and symptoms consistent with a VHF?

Signs and Symptoms of More Common VHFs: Ebola Virus Disease, Marburg Virus Disease, Lassa Fever and Crimean-Congo Hemorrhagic Fever

Disease Signs and symptoms Additional information
Ebola Virus Disease Fever, headache, muscle pain, fatigue, weakness, diarrhea, vomiting, abdominal pain, conjunctival injection, chest pain, hemorrhage Ebola: Signs and Symptoms
Marburg Virus Disease Fever, chills headache, muscle pain, maculopapular, rash, nausea, vomiting, chest pain, sore throat, abdominal pain, diarrhea, jaundice, hemorrhage Marburg hemorrhagic fever (Marburg HF): Signs and Symptoms
Lassa Fever Fever, nausea, vomiting, diarrhea, retrosternal chest pain, sore throat, muscle pain, enlarged cervical lymph nodes, abdominal pain, bleeding, maculopapular rash, conjunctivitis, headache Lassa Fever: Signs and Symptoms
Crimean-Congo Hemorrhagic Fever Fever, headache, back pain, join pain, abdominal pain, vomiting, conjunctival injection, facial flushing, petechial rash, jaundice, bleeding, photophobia, sore throat Crimean-Congo Hemorrhagic Fever: Signs and Symptoms

Isolate the patient

  • Place patient in a private room or separate enclosed area with private bathroom or covered bedside commode. Information on waste management for suspect or confirmed VHF patients.
  • Limit healthcare personnel who enter the room. Only essential healthcare personnel with designated roles should evaluate the patient and provide care to minimize transmission risk.
  • Duration of precautions should be determined on a case-by-case basis, in conjunction with local, state, and federal health authorities.
  • Appropriate personal protective equipment (PPE) should be worn by all personnel entering the patient’s room. Guidance on proper use of PPE for VHF.
  • More information on infection control practices.

Inform relevant health authorities

  • Immediately notify your hospital’s administration infection control program, and other appropriate staff.
  • Immediately notify your state/local health department
  • To speak to an epidemiologist please call the CDC’s Emergency Operations Center at 770-488-7100.

Treat the patient

  • Perform routine/appropriate therapeutic interventions (e.g. placement of peripheral IV, phlebotomy for diagnosis) as indicated by clinical status.
  • Dedicated medical equipment (preferable disposable, when possible) should be used for the provision of patient care.
  • All non-dedicated, non-disposable medical equipment used for patient care should be cleaned and disinfected according to manufacturer’s instructions and hospital policies.
  • Limit the use of needles and other sharps as much as possible.

Inform the laboratory

Arrange for testing

  • Decision to test for VHF should be made in consultation with relevant health department/CDC Viral Special Pathogens Branch.
  • To speak to an epidemiologist please call the CDC’s Emergency Operations Center at 770-488-7100.

Maintain a log

  • Facilities should maintain a log of all people entering the patient’s room. Log should contain full name and contact information for all persons entering patient’s room.
  • Facilities should develop policies for monitoring staff (e.g., healthcare personnel, environmental services, ancillary staff) who have contact with the patient.

Limit visitors

  • Avoid entry of visitors into the patient’s room.
  • Exceptions may be considered on a case by case basis for those who are essential for the patient’s wellbeing.

Establish procedures for monitoring and managing visitors

  • Facilities should develop policies for monitoring health care providers (HCP) attending to the patients.
  • Facilities should develop sick leave policies for HCP that are non-punitive, flexible and consistent with public health guidance.
  • Ensure that all HCP, including staff who are not directly employed by the healthcare facility but provide essential daily services, are aware of the sick leave policies.