Screening and Evaluating an Ill Person for Viral Hemorrhagic Fevers

Scope of guidance

This guidance applies to VHFs caused by infections with:

• Filoviruses (orthoebolaviruses and orthomarburgviruses)
• Arenaviruses [Lassa, Lujo, and South American hemorrhagic fever viruses (Guanarito virus, Sabia virus, Junin virus, Chapare virus, Machupo virus)]
• Rift Valley fever virus
• Crimean-Congo hemorrhagic virus

This guidance applies to other high-consequence diseases caused by viruses that require a specialized laboratory, are highly pathogenic, and have no vaccine or treatment currently available, like Nipah virus.

VHF case definitions

Suspect case

1. An epidemiological risk factor within 21 days (i.e., the incubation period) before the onset of symptoms AND
2. Signs and symptoms compatible with a VHF

Confirmed case

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

Screening for VHFs

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. This assessment includes getting a thorough history for all patients exhibiting symptoms compatible with a VHF to determine if they may have had exposure to the virus.

Initial screening questions

To screen an ill person presenting to a healthcare facility for a suspect VHF, ask the patient if they have been:

• In contact with a person who had a suspected or confirmed infection with a VHF, or any object contaminated by their body fluids in the past 21 days
• To an area with an active outbreak of a disease caused by a VHF, or where these diseases are endemic in the past 21 days [stay up to date on active travel notices and check CDC destination pages for endemic diseases]
• Working in a laboratory that handles VHFs

If the patient answers "No" to all initial screening questions, continue with routine evaluation and care. If concern remains, consult your health department for additional guidance.

If the patient answers "Yes" to one or more initial screening questions, ask about signs or symptoms compatible with a VHF.

Signs and symptoms

Primary signs and symptoms of a VHF often include:

• Fever (100.4°F/38.0°C) without use of antipyretics
• Severe headache
• Muscle and/or joint pain
• Weakness and fatigue
• Cough/difficulty breathing
• Sore throat
• Loss of appetite
• Gastrointestinal symptoms, including abdominal pain, diarrhea, and vomiting
• Chest pain
• Encephalitis
• Acute hearing loss
• Unexplained bleeding or bruising, including bleeding outside a normal menstrual cycle
• Red eyes, skin rash, and hiccups
• A concerning constellation of other signs and symptoms

If the patient is not reporting signs and symptoms compatible with a VHF or other high-consequence disease, continue with routine evaluation and care. If concern remains, consult your health department for additional guidance.

Infection control precautions

If the patient answered "Yes" to one or more screening questions AND is experiencing symptoms compatible with a VHF or other high-consequence disease, follow these recommended infection prevention and control (IPC) precautions for preventing transmission:

• Isolate the patient at a healthcare facility in a single room with private bathroom/covered bedside commode.
• Adhere to IPC procedures to prevent transmission, including wearing appropriate personal protective equipment (PPE).
• Use only essential healthcare workers trained in their designated roles and keep a log of all people entering the patient's room.
• Notify your facility's IPC program.

Further assessment

Once the patient is safely isolated, consult your state, tribal, local, or territorial public health department for testing recommendations. During this consultation, an in-depth public health interview will be conducted to review detailed travel and epidemiologic history and clinical course of the patient.

Conduct a public health interview

Your health department will assist in conducting a thorough public health interview. Questions related to risk exposure can help inform testing recommendations, including if the patient:

• Received pre-travel vaccinations
• Adhered to their malaria prophylaxis regimen if they traveled to a malaria-endemic country
• Reported any illness/death in travel companions or other contacts
• Had contact with someone who was sick or died, or with any object(s) contaminated by their body fluids
• Experienced a breach in IPC precautions that may have resulted in contact with the body fluids of a patient with a suspected or confirmed VHF
• Had contact with the body fluids of a person who is suspected or confirmed to have a VHF: urine, saliva, sweat, feces, vomit, breast milk, amniotic fluid, or semen
• Participated in any of the following activities while in an area with an active VHF outbreak or where VHFs are endemic:
  • Had contact with someone who was sick or died, or any objects contaminated by their body fluids
  • Attended/participated in funeral rituals, including preparing bodies for funeral or burial
  • Worked in a healthcare facility or laboratory
  • Visited a healthcare facility or traditional healer (as a visitor or patient)
  • Had contact with bats, pigs, rodents, camels, or other livestock or wild animals
  • Handled or consumed raw meat or other products harvested from animals
  • Worked or spent time in a mine/cave
  • Received a tick bite [in a CCHF-endemic area]
  • Consumed raw date palm sap [in a Nipah-endemic area]

Confirmatory testing

Decisions about testing for most VHFs will be coordinated by your state, tribal, local, or territorial public health department in coordination with CDC. Testing for these diseases may only be available at CDC or select laboratories within the Laboratory Response Network.

If VHF testing is not recommended

• Schedule a follow-up clinical consultation to review the patient's clinical status and laboratory test results.
• Discuss discontinuing VHF-specific IPC measures.

If VHF testing is recommended

• Determine if the patient requires transfer to a higher-tier facility.
• Test for other causes of illness.
• Perform routine laboratory testing to monitor the patient's clinical status.
• Use lab equipment with closed tube systems where the specimen container remains capped during testing. Centrifuges should have sealed buckets or sealed rotors that are loaded in a biosafety cabinet (BSC). After centrifugation, open the sealed buckets or rotors inside a BSC or enclosed hood.
• Malaria is the leading cause of travel-related hospitalizations and deaths. Perform malaria testing in any patient with a febrile illness who recently returned from a malaria-endemic country, irrespective of adherence to malaria prophylaxis.

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