Updated November 19, 2014.

In October 2014, weeks  after scares of an Ebola pandemic suffused global consciousness, Dr. Tom Frieden, director of the Centers for Disease Control and Prevention (CDC), said in his 30 years of working public health, he can only compare Ebola with AIDS.  And as was the case with AIDS many years ago, highly effective treatment directly aimed at this petrifying pathogen is elusive.

Currently, most treatment for Ebola is supportive meaning that symptoms are treated as they emerge in a patient.

   Nevertheless, there are some nascent experimental interventions that show some promise in directly combating the virus.

 

What is Ebola?

 

Ebola was first reported in 1976 following outbreaks in southern Sudan and northern Zaire (now the Democratic Republic of Congo or DRC) and has since menaced the populations of equatorial Africa with at least 34 (and one fictional) outbreaks.  Although no animal has been definitively identified as a reservoir for the disease, researchers suggests bats may be a source.  Along with the Marburg virus, Ebola belongs to the Filoviridae family of viruses and is made of genetic material called RNA.  Of note, Ebola exists in 5 strains--4 strains from Africa and one from the Philippines. As has been widely documented, Ebola is very deadly and kills as many as 90 percent of those affected in developing nations.  Of note, Ebola causes a viral hemorrhagic fever which result in high fever and bleeding.

Ebola is transmitted by either body fluids (blood, sweat, tears, saliva and possibly even semen) via mucosal membranes lining the mouth, eyes, nose, anus or genitalia or by breaks in the skin (needle sticks).

  Of note, the CDC classifies casual contact (like passing within 3 feet of a person with Ebola in a hospital or supermarket) as low risk. Ebola has an estimated 7- to 10-day incubation period meaning that after exposure it takes about this much time for symptoms to first appear.

Here are some typical symptoms caused by Ebola:

• headache (initial)
• nausea and vomiting (initial)
• body aches (initial)
• malaise (initial)
• rash
• slowed thinking
• diarrhea
• swelling (secondary to shock)
• bleeding
• sore throat

 

Current treatment of Ebola Virus

 

As mentioned earlier, treatment for Ebola is primarily symptomatic and targeted at the relief of symptoms as they develop.  Much treatment targets both bleeding and shock which are among the most worrisome complications of Ebola.  Patients with Ebola should be isolated and treated in the intensive care unit with barrier precautions in place—gowns, gloves, masks and goggles for all healthcare personnel in contact with the patient.

Patients with Ebola have been treated using the following measures:

• intensive fluid resuscitation (IV fluids)
• oral rehydration (drinking water)
• nutritional support
• electrolyte (body salt) management
• dialysis and mechanical ventilation in cases of end-organ damage (failure of the kidneys and lungs)
• pressors to maintain adequate blood pressure and blood circulation
• blood and blood products
• analgesics for pain relief
• antipyretics for fever
• antiemetics for nausea and vomiting
• antidiarrheal agents
• antibiotics for accompanying infections

 

Ebola experimental treatments

 

There is no cure or FDA-approved specific therapy for Ebola, and antiviral drugs like Ribavirin which are used to treat other types of RNA viruses have no effect on the disease.  Nevertheless, a number of nascent experimental treatments exist which directly target the virus itself.  Furthermore, in September 2014, the World Health Organization (WHO) released “interim guidance” which suggested using convalescent blood and plasma, a blood component, from recovered patients with Ebola as a means of immunization.

Here is a list of other experimental interventions directly aimed at the Ebola virus:

• Zmapp, a cocktail of monoclonal antibodies which fight proteins that constitute the Ebola virus, has shown promise in a handful of people.  (Currently, there is no more Zmapp available.) Other monoclonal antibodies such as HB-003 and ZMab have shown antiviral effects in macaques, a type of primate.  (Keep in mind that animal models aren’t human, so, although encouraging, such findings must be taken with a grain of salt.)
• Plasmapheresis is a treatment which removes blood plasma from the body, treats it and returns it to the body.
• Small interfering RNAs or siRNAs (TMK-100201 and TMK-100802), phosphorodiamidate moropholino antisense oligomers, polyinosinic-polycytidylic acid stabilized with polylysine and carboxymethylcellulose: If not readily apparent from their very long names, these molecules interfere with viral replication and are currently all in Phase 1 clinical trials and thus a long way from FDA approval.
• Nucleoside-analog BCX4430 also interferes with viral replication and has shown promise in macaques.    Additionally, nucleotid-analog favipiravir has shown clinical efficacy in mice (which are even less like humans than macaques).
• Selective estrogen receptor modulators (SERMs) including clomiphene and toremifene have also proved effective in combating Ebola in mice.

 

What does this all mean to you?

 

Without a doubt, Ebola is serious and disquieting especially in West Africa where thousands have already died of the disease.  Furthermore, we currently have no cure for the disease, and all direct therapeutic interventions which directly target the Ebola virus are nascent and experimental. Nevertheless, when treated in developed nations, many people have survived the disease with limited sequelae or clinical consequences.   

Fortunately, the CDC has stepped up to the plate and done its best to assuage concerns and consternation that could have arisen among the general public.  The CDC has let us all know that there’s no cause for alarm.  According to the CDC’s website, Ebola poses no substantial risk to the U.S. population.  Furthermore, the “CDC’s mission is to protect the health of all Americans including those who may become ill while overseas.  Ebola patients can be managed safely when appropriate precautions.” 

On a final note, as of October 10, 2014, only one person has traveled to the United States unwittingly carrying the Ebola virus.  (Unfortunately, despite receiving delayed medical attention and support, this person died.)  However, the CDC has expended public health resources to identify and monitor all patient contacts and possible contacts.  (Most recently, a nurse caring for this patient has developed Ebola herself.)  Moreover, the CDC has even gone so far as recommending proper burial procedure for people who die of the disease.  

 

Sources

 

Clark, DV et al.  Clinical Management of Filovirus-Infected Patients.  Virus 2012. 2012; 4: 1668-1686.

DynaMed [Internet]. Ipswich (MA): EBSCO Information Services. 1995 –   .[cited 2010 Mar 23].  Accessed October 12, 2014.

Feldman, H et al.  Ebola haemorrhagic fever. Lancet. 2011 March 5; 377: 849-862.

Fisher-Hoch SP. Chapter 60. Viral Hemorrhagic Fevers. In: Hall JB, Schmidt GA, Wood LH. eds. Principles of Critical Care, 3e. New York, NY: McGraw-Hill; 2005.  Accessed October 12, 2014.

Grey MR, Spaeth KR. Chapter 13. Viral Hemorrhagic Fevers. In: Grey MR, Spaeth KR. eds. The Bioterrorism Sourcebook. New York, NY: McGraw-Hill; 2006. Sectionid=39825484. Accessed October 12, 2014.

Peters CJ. Chapter 197. Ebola and Marburg Viruses. In: Longo DL, Fauci AS, Kasper DL, Hauser SL, Jameson J, Loscalzo J. eds. Harrison's Principles of Internal Medicine, 18e. New York, NY: McGraw-Hill; 2012.Accessed October 12, 2014.