Ebola emergency department evaluation

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: : Joseph Nasr, M.D.[2]; Yazan Daaboul, M.D.

Overview

Triage and evaluation processes in the emergency department (ED) should consider and systematically assess patients for the possibility of Ebola virus disease (EVD). The CDC has organized the ED approach around an Identify–Isolate–Inform framework: healthcare facilities should be able to rapidly identify patients with relevant exposure history and signs or symptoms compatible with EVD, immediately isolate any suspected patient, and immediately inform the hospital/facility infection control program, other appropriate facility staff, and the state, tribal, local, or territorial (STLT) public health agencies. Healthcare facilities must implement administrative and environmental controls and provide onsite management and oversight on the safe use of personal protective equipment (PPE).

No single sign or symptom is pathognomonic for EVD; the decision to test is primarily driven by assessing epidemiologic risk factors and ruling out more common causes of illness, particularly [[[malaria](https://www.openevidence.com/rare-disease/malaria)]], which remains the most likely diagnosis in patients with suspected viral hemorrhagic fever. Blood films and other essential tests (blood cultures, complete blood count, and tests of renal function and liver function) should not be delayed pending the results of tests for viral hemorrhagic fever.

The average clinical course of EVD is approximately 8–10 days with an average case fatality rate of approximately 50%, though this varies substantially by outbreak, species, and level of supportive care provided. Two FDA-approved monoclonal antibody treatments (Ebanga and Inmazeb) are now available for Zaire ebolavirus infection, and early treatment is critical: the odds of death increase by 11% for each day of delay between symptom onset and treatment initiation.

Triage Recommendations

Step 1: Identify

Immediately upon entrance to the ED, or in advance of entry if possible, a relevant exposure history should be taken. The key screening question is whether the patient has resided in or traveled to a country with widespread Ebola virus transmission, or had contact with an individual with confirmed EVD, within the previous 21 days. Because the signs and symptoms of EVD may be nonspecific and are present in other infectious and noninfectious conditions that are more frequently encountered, relevant exposure history should be first elicited to determine whether EVD should be considered further. If the patient is unable to provide history due to clinical condition or other communication barrier, history should be elicited from the next most reliable source (e.g., family, friend, or EMS provider).

All patients presenting with a possible acute infectious illness should also be screened for occupational history to identify epidemiologic risk factors for viral special pathogens, including contact with bats, bat guano, non-human primates, or other forest animals; work in caves or mines; and attendance at funerals in endemic areas.

Step 2: Assess for Compatible Signs and Symptoms

Patients who meet the exposure criteria should be further questioned regarding the presence of signs or symptoms compatible with EVD. These include:

• Fever (subjective or ≥100.4°F or 38.0°C)*
• Headache*
• Weakness/fatigue*
• Muscle pain*
• Vomiting*
• Diarrhea*
• Abdominal pain*
• Hemorrhage (e.g., bleeding gums, blood in urine, nose bleeds, coffee ground emesis, or melena)*
• Conjunctival injection*
• Maculopapular rash*
• Hiccups*
• Dysphagia*

All patients should be routinely managed using precautions to prevent any contact with blood or body fluids. If an exposure history is unavailable, clinical judgment should be used to determine whether to empirically implement the isolation protocol.

EVD typically begins as a nonspecific febrile illness characterized by malaise, fatigue, and myalgia, with an incubation period of 2–21 days (typically 6–10 days). A few days later, gastrointestinal manifestations develop in many patients, with anorexia, nausea, vomiting, and diarrhea. Fluid losses can be substantial—up to 10 liters per day. Bleeding abnormalities occur in less than half of affected patients, usually manifested as bleeding from the gums, petechiae, oozing from venipuncture sites, subconjunctival hemorrhage, and blood in vomitus and stool. Importantly, during the West African outbreak, fever was absent in at least 10% of cases.

Stage	Timing	Key Features
Early (Days 1–3)	Onset of illness	Fever, malaise, fatigue, myalgia, headache
Gastrointestinal (Days 3–10)	Peak illness	Nausea, vomiting, diarrhea (up to 5–10 L/day), abdominal pain; anorexia, dysphagia
Critical/Hemorrhagic (Days 7–12)	Progression to shock	Hypovolaemic shock, hemorrhage (petechiae, mucosal bleeding, oozing from venipuncture sites), DIC, acute kidney injury, confusion/delirium
Recovery or Death	Days 10–14+	Gradual recovery in survivors; multi-organ failure and death in fatal cases; sudden death from possible cardiac arrhythmia can occur even during recovery

Adapted from Malvy et al. (2019) and Feldmann et al. (2020).

Step 3: Isolate

If a relevant exposure history is reported and signs or symptoms consistent with EVD are present, the following measures should be implemented IMMEDIATELY:

1. Isolate the patient in a private room or separate enclosed area with a private bathroom or covered, bedside commode and with the door to the hallway closed. If the patient is arriving by EMS transport, the ED should be prepared to receive the patient in a designated area (away from other patients) and have a process in place for safely transporting the patient on the stretcher to the isolation area with minimal contact with non-essential healthcare workers or the public.

1. Implement appropriate PPE based on the patient's clinical status (see PPE section below).

1. Limit personnel — only essential healthcare workers with designated roles should provide patient care. A log should be maintained of all personnel who enter the patient's room.

1. Use dedicated equipment — all equipment used in the care of these patients should not be used for the care of other patients until appropriate evaluation and decontamination. Preferably use disposable equipment.

1. Consider placement in a negative pressure airborne infection isolation room (AIIR) if available, particularly for patients with respiratory symptoms.

1. Where possible, the interior of the patient's room should be visible to healthcare professionals outside the room (e.g., window). Consider using methods of communicating with the patient that do not require entry into the room (e.g., mobile phone, electronic tablet, or nursing call intercom).

Step 4: Inform

1. Notify the Hospital Infection Control Program and other appropriate staff.

1. IMMEDIATELY report to the relevant STLT health department of patients with EVD exposure history regardless of symptoms.

1. Contact CDC (770-488-7100) — for patients for whom a viral special pathogen is a serious consideration, consultation with CDC is highly recommended and would be coordinated by the STLT public health department.

Step 5: Further Evaluation

Once appropriate PPE has been put on, continue obtaining additional history and performing physical examination and routine diagnostics and interventions, which may include placement of peripheral IV and phlebotomy. The decision to test the patient for EVD should be made in consultation with the relevant STLT health department. Patient evaluation should be conducted with dedicated equipment as required for patients on transmission-based precautions.

Routine diagnostic testing to monitor the patient's clinical status and diagnostic testing for other potential causes of illness should be pursued while viral special pathogen testing is underway. The risk of viral special pathogen transmission in a clinical laboratory is the same as other bloodborne pathogens (e.g., HIV, hepatitis B virus, hepatitis C virus).

Algorithm for the Emergency Department Evaluation and Management of Patients with Possible Ebola Virus Disease

Shown below is the CDC algorithm for the emergency department evaluation and management for patients who present with possible Ebola virus disease. Click here to access the PDF version of the CDC algorithm and print it.

***

Patient encounter in emergency department (ED)

Has the patient lived in or traveled to a country with widespread Ebola transmission or had contact with an individual with confirmed Ebola Virus Disease within the previous 21 days?

Yes

No

Does the patient have FEVER (subjective or ≥ 100.4 °F or 38.0 °C) OR Ebola-compatible symptoms (listed below)? Headache Weakness Muscle pain Vomiting Diarrhea Abdominal pain Hemorrhage

Continue with usual triage and assessment

Yes

No

Continue with usual triage and assessment Notify relevant health department Monitor for fever and symptoms for 21 days after last exposure in consultation with the relevant health department

ISOLATE and determine PPE needed Place patient in private room or separate enclosed area with private bathroom or covered, bedside commode Only essential personnel with designated roles should evaluate patient and provide care to minimize transmission risk Maintain a log of all personnel entering the room

INFORM: IMMEDIATELY notify the hospital infection control program and other appropriate staff IMMEDIATELY report to the STLT health department Consider consultation with CDC (770-488-7100)

The use of PPE should be determined based on the patient's clinical status Is the patient exhibiting obvious bleeding, vomiting, copious diarrhea, or a clinical condition that warrants invasive or aerosol-generating procedures (e.g. intubation, suctioning, active resuscitation)?

Yes

No

Use PPE designated for the care of hospitalized patients (see table below) If the patient requires active resuscitation, this should be done in a pre-designated area using pre-designated equipment Avoid aerosol-generating procedures if possible; when necessary, perform in AIIR with doors closed

For clinically stable patients, healthcare worker should at minimum wear: Full face shield and surgical face mask Single-use fluid-resistant gown (to at least mid-calf) Two pairs of examination gloves with extended cuffs If patient's condition changes, re-evaluate PPE

Further evaluation and management Complete history and physical examination; decision to test for Ebola should be made in consultation with STLT health department Perform routine interventions (e.g. placement of peripheral IV, phlebotomy for diagnosis) as indicated by clinical status Do NOT delay routine diagnostic testing (malaria smears, blood cultures, CBC, BMP) while awaiting EVD results Evaluate patient with dedicated equipment (e.g. stethoscope) Initiate empiric treatment as clinically indicated (antimalarials, broad-spectrum antibiotics)

Algorithm adapted from the Centers for Disease Control and Prevention — Identify, Isolate, Inform: Emergency Department Evaluation and Management for Patients Who Present with Possible Ebola Virus Disease and updated with CDC Yellow Book (2025) guidance.

Personal Protective Equipment

PPE requirements vary based on the patient's clinical status. A trained observer should supervise all PPE donning and doffing procedures.

Patient Status	Minimum PPE Requirements
Suspected infection, clinically stable, no bleeding/vomiting/diarrhea	Single-use fluid-resistant gown (to at least mid-calf) OR fluid-resistant coveralls without integrated hood; full face shield; facemask; two pairs of examination gloves with extended cuffs (at minimum, outer gloves with extended cuffs)
Confirmed infection OR suspected infection with clinical instability, bleeding, vomiting, or diarrhea	Single-use impermeable gown (to at least mid-calf) OR impermeable coveralls; PAPR or NIOSH-approved N95 respirator; two pairs of examination gloves with extended cuffs; boot covers (to at least mid-calf); apron (torso to mid-calf level)

Adapted from CDC Yellow Book (2025), Table 10.7.4.

Aerosol-generating procedures (AGPs) should be avoided if possible. When AGPs are necessary, they should be conducted in a private room and ideally in an airborne infection isolation room; room doors should be kept closed during the procedure except when entering or leaving the room, and entry and exit should be minimized during and shortly after the procedure.

Differential Diagnosis

The differential diagnosis of EVD is broad, particularly early in the disease course when symptoms are nonspecific. Malaria is the most common diagnosis among ill travelers returning from West Africa, accounting for 40.3% of diagnoses in a GeoSentinel surveillance study of 770 nonimmigrant travelers from Sierra Leone, Liberia, or Guinea, with Plasmodium falciparum or severe malaria in 86% of malaria cases.

Category	Differential Diagnoses	Distinguishing Features
Parasitic	Malaria (especially P. falciparum)	Most common diagnosis in febrile travelers from sub-Saharan Africa; thick/thin blood smears or RDT should be performed immediately; co-infection with EVD is possible and associated with higher mortality
Bacterial	Typhoid fever, Shigellosis, meningococcal septicaemia, Leptospirosis, plague, anthrax, relapsing fever, typhus, murine typhus	Blood cultures, stool cultures; typhoid fever is the second most common serious tropical infection in travelers
Viral	Marburg virus disease, Lassa fever, Crimean-Congo hemorrhagic fever, dengue fever, yellow fever, Chikungunya fever, influenza, COVID-19, acute HIV infection, fulminant viral hepatitis	Other viral hemorrhagic fevers require similar isolation precautions; influenza and COVID-19 are common and should be tested for at point of care
Other	Acute gastroenteritis, urinary tract infection, upper respiratory tract infection, sepsis of other etiology	Common "cosmopolitan" infections should not be overlooked; acute diarrhea was the second most common diagnosis (12.3%) in the GeoSentinel study

Adapted from Boggild et al. (2015), Feldmann Geisbert (2011), and Thwaites Day (2017).

EVD Prediction Scores

Several clinical prediction scores have been developed to assist with triage of suspected EVD cases. An extended clinical prediction score (ECPS) incorporating 13 clinical predictors and time from disease onset, developed from data on 10,432 subjects (651 EVD cases) during the eastern DRC outbreak, achieved an AUROC of 0.88 (95% CI: 0.86–0.89). At a threshold of −1 point, the ECPS yielded sensitivity of 78.8% and specificity of 81.4%. Use of the ECPS as a joint approach to isolate EVD suspects reduced the number of unnecessary isolations by 65.7%. A rapid decision algorithm for patient triage during Ebola outbreaks identified 4 highly predictive variables that could distinguish patients at high risk for infection independent of their scores. However, the overall diagnostic accuracy of clinical prediction tools has generally been too low to be meaningfully integrated into clinical triage systems as standalone tools, and any negative result should be confirmed with molecular testing.

Laboratory Evaluation in the Emergency Department

Routine Laboratory Testing

Routine diagnostic testing should not be delayed while awaiting EVD-specific results. A laboratory testing toolkit has been developed to assist frontline healthcare facilities in providing basic laboratory testing required for the care of suspected viral hemorrhagic fever patients.

Key laboratory safety principles:

• Use equipment with closed tube systems in which the specimen container stays capped during testing*
• If centrifugation is necessary, centrifuges should have sealed buckets or sealed rotors; load and unload in a biosafety cabinet (BSC)*
• Blood culture instruments (automated and benchtop) can be used after careful risk assessment; subculture any positive bottles within a BSC*
• Malaria testing: immediate blood smears with same-day results is ideal; thin smears can be inactivated with methanol and safely read. If timely blood smears are not available, a rapid diagnostic test can be performed*
• Glucometry and rapid tests for influenza, COVID-19, respiratory syncytial virus, and group A Streptococcus can be performed at the point of care*
• If the healthcare facility elects to run specimens on point-of-care instruments, they should be set up in a dedicated space outside of the patient's room*
• Inform the laboratory of specimens submitted from patients with possible viral hemorrhagic fever*

Characteristic Laboratory Findings in EVD

Parameter	Typical Findings	Prognostic Significance
Viral load (RT-PCR Ct value)	Detectable by day 3 of symptoms; peaks days 3–7; fatal cases have 10–100 fold higher viraemia than survivors	Strongest prognostic factor: odds of death decrease by 34% per unit increase in Ct value (OR 0.66; 95% CI, 0.62–0.71); mortality 67% with Ct 22 vs 11% with Ct >22 in PALM trial treatment arms
Creatinine	Elevated; acute kidney injury present in up to 50% of cases	Independent predictor of death: OR 1.43 per 1 mg/dL increase (95% CI, 1.31–1.56)
AST	Markedly elevated (typically exceeds ALT); high AST:ALT ratio suggests diffuse cellular damage	OR 1.15 per 100 U/L increase (95% CI, 1.11–1.20)
ALT	Elevated	OR 1.43 per 100 U/L increase (95% CI, 1.33–1.54)
WBC	Early leukopenia (as low as 1,000 cells/μL) with lymphopenia, followed by neutrophilia with left shift and atypical lymphocytes	Variable prognostic value
Platelets	Thrombocytopenia (50,000–100,000 cells/μL)	Mild thrombocytopenia common; severe thrombocytopenia associated with hemorrhagic complications
Electrolytes	Hypokalaemia, hyponatraemia, hypocalcaemia common	Electrolyte abnormalities present even in early disease; correction is a key component of supportive care
Coagulation studies	Prolonged PT and aPTT; elevated fibrin split products indicating DIC	Coagulopathy indicates severe disease
Other	Elevated CK/CPK, elevated amylase (with or without clinical pancreatitis), metabolic acidosis, hyperproteinaemia, proteinuria	Elevated CK suggests myositis; metabolic acidosis associated with shock and renal failure

Adapted from Feldmann et al. (2020), Malvy et al. (2019), Feldmann Geisbert (2011), Hunt et al. (2015)