Clinical Screening and Diagnosis for VHFs

Key points

  • Viral hemorrhagic fevers (VHFs) are rare and deadly viral illness that are reportable in all U.S. states and territories.
  • Be alert for and evaluate any patients that are suspected of having a VHF.
  • If you suspect a VHF after screening, isolate the patient and notify your health department.

VHF Case Definitions

Suspect case

  1. Signs and symptoms compatible with a VHF


  1. An epidemiological risk factor within 21 days (i.e., the incubation period) before the onset of symptoms.

Confirmed case

Laboratory-confirmed diagnostic evidence of a VHF (i.e., through molecular and/or serologic testing).

Screening guidelines

The majority of febrile patients presenting in U.S. healthcare facilities do not have a VHF, but early symptoms are similar to other febrile illnesses. It is important to systematically assess patients for the possibility of a VHF through a triage and evaluation process.

Identify potential exposures

Getting a thorough history is important for all patients exhibiting symptoms compatible with a VHF who may have had an exposure to the virus.

Important questions to ask to begin assessing exposure risk:

  • Have you been in contact with a person with suspect or confirmed VHF in the past 21 days (for example touching, caring for, etc.)?
  • Have you been to an area with an active VHF outbreak or where VHF is endemic in the past 21 days? Stay up to date on active travel notices.

Ask about VHF risk factors

Exposure risks for VHFs may include the following activities.

  • Contact with a symptomatic person with a suspected or confirmed VHF, or any objects contaminated by their body fluids
  • Experienced a breach in infection prevention and control precautions that result in the potential for contact with body fluids of a patient with a suspected or confirmed VHF
  • Contact with semen from a person who has recovered from a VHF
  • Participated in any of the following activities while in an area with an active VHF outbreak or where VHFs are endemic:
    • Having contact with someone who was sick or died, or any objects contaminated by their body fluids
    • Attending/participating in funeral rituals, including preparing bodies for funeral or burial
    • Working in a healthcare facility or laboratory
    • Visiting a healthcare facility or traditional healer
    • Having contact with bats or wild animals
    • Working or spending time in a mine/cave

Ask about signs or symptoms compatible with a VHF

Signs and symptoms of most VHFs are nonspecific and similar to many other common causes of febrile illness in returning travelers. Assess a patient's signs and symptoms along with their travel history and epidemiologic risk factors before initiating immediate infection control measures.

VHF symptoms can appear anywhere from 2 to 21 days after exposure to the virus.

Illness typically progresses from "dry" symptoms (fever, aches, fatigue) to "wet" symptoms (diarrhea, vomiting, and in some cases, bleeding). A person with a VHF is not contagious until the appearance of symptoms.

Primary signs and symptoms of VHFs often include some or several of the following:

  • Fever (≥100.4°F/38.0°C)
  • Aches and pains, such as severe headache and muscle and/or joint pain
  • Weakness and fatigue
  • Sore throat
  • Loss of appetite
  • Gastrointestinal symptoms including abdominal pain, diarrhea, and vomiting
  • Unexplained hemorrhaging, bleeding or bruising
  • Red eyes, skin rash, and hiccups

What to do next

If Patient Evaluation Indicates Possible Infection with a VHF, Take Action


  • Isolate the patient in a single room with a private bathroom or a covered bedside commode.
  • Adhere to infection prevention and control procedures to prevent transmission through direct or indirect contact, including wearing appropriate PPE and using dedicated equipment.
  • Use only essential healthcare workers trained in their designated roles for patient care and keep a log of everyone who enters and leaves the patient's room.
  • Perform only necessary tests and procedures and avoid aerosol-generating procedures.


  • Notify your facility's Infection Prevention and Control Program and other healthcare personnel of a suspect VHF case.
  • Contact the local or state health department for consultation about VHF testing.

If the patient is not reporting signs and symptoms compatible with a VHF but concern remains, consult Local/State Health Department for additional guidance on testing recommendations.