This is the transcript of an interview with Tim Uyeki, MD, MPH, the Centers for Disease Control and Prevention (CDC) clinical team lead (Ebola response) and chief medical officer for the influenza division at the CDC’s National Center for Immunization and Respiratory Diseases.

JMH: Thank you for taking the time for this interview. With all the excitement and anxiety, it is important to send a clear and precise message about this disease. Recognizing how busy you are, let me get quickly to our questions. My first question is, from a clinical perspective, what would you recommend for initial evaluation and diagnosis?

TU: Thank you Jon Mark. I appreciate this opportunity to help inform the ACEP membership about Ebola. The key, from a clinical perspective, is a good history. Essentially, there are two groups of people who are most at risk. The first is individuals recently returned from West Africa, and specifically the most affected countries of Liberia, Guinea, and Sierra Leone who have had direct contact with the blood or bodily fluids of a person who was sick with or died of Ebola virus disease (household, community, or health care setting). The second group would be individuals with direct contact with the blood or bodily fluids of a patient with Ebola virus disease in the United States (close contacts, including health care personnel). To date, in the United States, there have only been two imported cases and two secondary cases (nosocomial transmission to two nurses), other than a handful of individuals who had been medically evacuated for further medical care from West Africa. The key pieces of information to obtain are recent travel history, recent contact history, and timeline of illness signs and symptoms.

JMH: That’s excellent information. So, really, the risk of transmission in the United States is extremely low. How long after exposure do symptoms typically appear? Let’s say that someone presents with possible exposure—what are the signs and symptoms of the disease?

TU: In general, the average incubation period after exposure to fever and symptom onset is eight to 12 days, though symptoms may appear anywhere from two to 21 days after exposure. Initial signs and symptoms are nonspecific and may include low-grade temperature elevation, fatigue, chills, weakness, anorexia, and malaise. Within four to five days, profuse watery diarrhea, nausea, vomiting, and abdominal pain can start along with a high fever (>38.6º C). Substantial gastrointestinal fluid losses can lead to intravascular volume depletion, hyponatremia, hypokalemia, hypomagnesemia, and hypocalcemia. Conjunctival injection or subconjunctival hemorrhage may be present. Most patients develop a significant transaminitis with aspartate transaminase (AST) markedly elevated compared to alanine transaminase (ALT). Some patients may also develop a diffuse erythematous maculopapular rash on the face and torso by days four to six. Although hemostasis is impaired, frank hemorrhage is not common and is usually manifested by gastrointestinal tract bleeding and sometimes with oozing from mucous membranes and intravenous catheter sites in persons with severe disease later in the clinical course. Central nervous system involvement can be manifested by delirium, agitation, seizures, and coma. Patients with fatal disease usually develop more severe clinical signs early during the clinical course and die typically between days six and 16 of complications including multiorgan failure and septic shock.

JMH: One question that I am sure our readers will want to know is, “When are patients infectious?”

TU: While symptomatic individuals are considered infectious, it is clear that the sicker you are, the greater the viremia. So someone with mild initial symptoms within the first 72 hours of clinical disease could have a blood specimen collected that tests negative for Ebola virus with real-time reverse transcription polymerase chain reaction (RT-PCR). Therefore, if clinical suspicion remains high for Ebola virus disease, it is important to retest symptomatic individuals after 72 hours from illness onset. There is a correlation between the level of viremia and clinical severity. Persons with Ebola virus disease will become progressively worse with higher levels of Ebola virus in their blood, and clinical recovery is correlated with decreasing viremia.

JMH: Along with the concerns about the potential for spread, what should our members do to protect themselves, staff, and other patients?

TU: The discussions and concerns related to personal protective equipment (PPE) are very real issues for health care workers. Based upon the most recent cases, we have updated the specific instructions for PPE. It is important to wear the appropriate PPE and to make sure that donning and doffing the gear is done correctly. Health care workers caring for suspected or confirmed Ebola virus disease patients should have no skin exposure. I would recommend visiting the CDC website for the most up-to-date information. In brief, rapid identification and isolation of suspected cases is important, with implementation of recommended PPE and infection control precautions. Ebola virus is transmitted by direct exposure to blood and bodily secretions (vomit, stool, urine) of a symptomatic patient with Ebola virus disease. Ebola virus disease is not a respiratory illness but a systemic disease with multiorgan infection that triggers a host inflammatory response. This is in contrast to respiratory diseases caused by rare infections such as MERS-CoV and very common infections due to influenza A and B viruses. Work with your hospital infection control to be sure you have an up-to-date response plan.

JMH: Any concluding thoughts or recommendations?

TU: The travel history is extremely important. However, it is critical to remember that the vast majority of sick individuals with fever who have traveled recently from West Africa do not have Ebola virus disease. Also, the most-affected countries are Sierra Leone, Liberia, and Guinea, not all of West Africa or sub-Saharan Africa. In fact, the most common diagnosis in a returned traveler with fever from West Africa is malaria. Another diagnosis to consider is typhoid fever. In all the excitement and anxiety about Ebola, be sure to consider more-likely causes of fever, including common community-acquired pathogens in the United States, depending upon how long the person has been back in the United States. Another key point is to take a detailed history of the timeline and progression of clinical signs and symptoms. Even though the initial signs and symptoms of Ebola virus disease are nonspecific, understanding the progression of symptoms can help point to other etiologies. For example, vomiting and diarrhea do not typically occur until about four to five days after illness onset in Ebola virus disease—therefore, a patient who presents with fever and diarrhea occurring at illness onset is very unlikely to have Ebola virus disease.

A person who presents with sudden onset of fever, cough, sore throat, and nasal congestion or rhinorrhea is likely to have influenza or other common respiratory viral diseases. This is especially true if household contacts are sick with similar respiratory illness, so ask about similar illness in family members, household contacts, and close contacts. As we approach the fall/winter respiratory virus season, clinicians should not suspect Ebola virus disease in persons with fever who have not traveled recently to West Africa or those who do not have a history of direct contact with the bodily fluids of a person who was sick or recently died of suspected or confirmed Ebola virus disease. Of course, we do not want to miss any imported cases of Ebola virus disease. However, even though there will likely be some medically evacuated patients and rare sporadic imported cases of Ebola virus disease in the United States over the next year, such cases will remain rare here.

Also, be sure to tell you readers that there is much more information on the CDC website. This is the best single location for updated information about Ebola virus disease and other infectious diseases.

JMH: Thank you again for taking the time to speak with me. I am sure that our members will appreciate your comments and recommendations.

Dr. Hirshon is associate professor of emergency medicine at the University of Maryland School of Medicine in Baltimore and a member of the ACEP Board of Directors.