Ebola virus disease (EVD), often referred to simply as Ebola, is a severe illness that can be fatal in humans. It represents a continuing public health concern due to its capacity to cause widespread outbreaks and its high mortality rate, which has historically ranged from 25% to 90% in past outbreaks. First identified in 1976 near the Ebola River in the Democratic Republic of Congo, this disease has since caused multiple outbreaks primarily in Central and West Africa, prompting significant global attention.
What Ebola Is
Ebola virus disease is caused by viruses belonging to the Ebolavirus genus, part of the Filoviridae family. Four species are known to cause illness in humans, while a fifth affects nonhuman primates.
Ebola is considered a zoonotic disease, meaning it can be transmitted from animals to humans. While the natural reservoir host of the Ebola virus remains unknown, fruit bats are considered a likely natural reservoir based on evidence and the nature of similar viruses. Once the virus enters the human body, it can lead to severe illness with hemorrhagic symptoms, affecting multiple organ systems and potentially leading to multi-organ failure.
How Ebola is Transmitted
Ebola is spread through direct contact with the blood or other bodily fluids of a person who is sick with or has died from Ebola. These bodily fluids include urine, feces, saliva, vomit, breast milk, semen, and sweat. Transmission can also occur through indirect contact with objects contaminated with these fluids, such as needles or medical equipment.
Ebola is not an airborne disease; it does not spread through respiratory droplets like the common cold or flu. The virus is only transmissible when an infected individual begins to show symptoms. Even after a person recovers, the virus can persist in certain bodily fluids, such as semen, for an extended period.
Signs, Symptoms, and Diagnosis
The incubation period for Ebola, the time from infection to symptom appearance, ranges from 2 to 21 days, with an average onset between 8 to 10 days. Initial symptoms often appear suddenly and include fever, fatigue, muscle pain, headache, and a sore throat. These early signs can be similar to other common illnesses, making early identification challenging.
As the disease progresses, usually within one to two days, symptoms become more severe. These can include vomiting, diarrhea, and a rash. Further progression can lead to impaired kidney and liver function, and internal and external bleeding, which can result in multiple organ failure.
Diagnosis of Ebola is primarily conducted through blood tests that detect the presence of the virus or antibodies produced in response to the infection. Common diagnostic methods include Reverse Transcription Polymerase Chain Reaction (RT-PCR) and Enzyme-Linked Immunosorbent Assay (ELISA). Early diagnosis is important for effective management of the disease and for implementing measures to prevent its spread.
Managing the Disease and Preventing Spread
Managing Ebola virus disease focuses on providing supportive care to patients. This includes rehydration through oral or intravenous fluids to combat dehydration caused by vomiting and diarrhea. Other supportive measures involve maintaining blood pressure, managing pain, and treating any co-existing infections. In recent years, monoclonal antibody therapies and antiviral drugs have been developed and approved, showing promise in improving patient outcomes.
Preventing the spread of Ebola relies on a combination of public health strategies. Vaccination programs have been instrumental in controlling outbreaks in affected regions. Strict infection control practices in healthcare settings are important, involving the consistent use of personal protective equipment (PPE) by healthcare workers and thorough sterilization of medical equipment.
Community engagement and public health education inform people about how the virus spreads and how to protect themselves. Safe and dignified burial practices for individuals who have died from Ebola are also implemented to prevent further transmission. Surveillance systems, contact tracing to identify exposed individuals, and isolation of confirmed cases are used to contain outbreaks.