• Infectious Diseases A-Z: Understanding the Ebola outbreak

microscopic view of the Ebola virusGlobal health leaders continue their work to contain the latest outbreak of Ebola virus disease in the Democratic Republic of the Congo. The World Health Organization began sending the first doses of the experimental Ebola vaccine to the outbreak area May 16.

“The experimental Ebola vaccine that is now being used in the current outbreak happening in the Democratic Republic of the Congo has been developed over the last several years, and it seems to have really good promise in stopping these outbreaks," says Dr. Pritish Tosh, an infectious diseases specialist at Mayo Clinic.

"Ebola is a viral hemorrhagic fever. This is a viral infection that generally originates in parts of Africa. When it infects humans, it causes really severe disease and often leads to death," says Dr. Tosh. "In 2014, the largest Ebola outbreak ever recorded occurred. It was largely in West Africa. Thankfully, due to large international efforts, that outbreak was able to be stopped. Now, in certain parts of Africa, specifically the Democratic Republic of the Congo, Ebola is an endemic disease, meaning that there are sporadic cases that occur every year.”

Watch: Dr. Pritish Tosh explains Ebola virus disease.

Journalists: Broadcast-quality sound bites are in the downloads.

“The most common way Ebola is transmitted is from person-to-person through body secretions," says Dr. Tosh. Unlike respiratory viruses, Ebola is not transmitted through the air nor can it be spread by particles that remain in the air after an infected person coughs or sneezes.

Body fluids that can transmit Ebola include:

  • Blood
  • Breast milk
  • Feces
  • Mucus
  • Saliva
  • Semen
  • Sweat
  • Tears
  • Urine
  • Vomit

“The virus is aggressive," says Dr. Tosh. Those infected may develop sudden onset of fever, muscle pain, headache followed by vomiting, diarrhea, internal and external bleeding, multiple organ failure and possibly death. Those infected with the virus are not contagious until they develop symptoms.

The Centers for Disease Control and Prevention (CDC) issued a travel alert in response to the current Ebola outbreak. The CDC says the risk for most travelers to the Democratic Republic of the Congo is low outside of the Bikoro area, but travelers could be infected if they come into contact with an infected person’s blood or body fluids.

Malaria and typhoid concerns

Ebola is not the only concern for those who wishing to visit the Democratic Republic of Congo. Dr. Tosh says travelers heading outside of the U.S. should seek advice prior to travel for reasons unrelated to Ebola, namely to prevent common travel-related infections such as malaria and typhoid.

“If you are traveling to anywhere outside of the U.S., you should seek advice on what you can do to prevent infection," he says."The people who are often the highest risk of a travel-related illness are those who think they are at the lowest risk. They are people who were born in that country or raised in that country and now are living in the U.S., and going back to visit friends and relatives. Their gut and immunity are now American.”