Ebola hemorrhagic fever

What is Ebola virus disease?

Ebola virus disease (EVD) is formerly known as Ebola Haemorrhagic Fever. It is a severe, often-fatal viral disease affecting humans and nonhuman primates. The disease is caused by infection with Ebola virus which belongs to the family called Filoviridae. The disease has appeared sporadically since its initial recognition in 1976. Confirmed cases of EVD have been reported in sub-Saharan and west Africa region, such as the Democratic Republic of the Congo, Gabon, Sudan, Cote D' Ivoire, Uganda, the Republic of the Congo, Guinea, Liberia and Sierra Leone.

The incubation period for EVD ranges from 2 to 21 days. It is often characterized by the sudden onset of fever, intense weakness, muscle pain, headache and sore throat. This is followed by vomiting, diarrhoea, rash, impaired kidney and liver function, and in some cases, both internal and external bleeding. The mortality rate can be up to 90%.

How does it spread?

Ebola virus is introduced into the human population through close contact with the blood, secretions, organs or other bodily fluids of infected animals. In Africa, infection has been documented through the handling of infected chimpanzees, gorillas, fruit bats, monkeys, forest antelope and porcupines found ill or dead or in the rainforest.

Ebola virus then spreads in the community through human-to-human transmission, with infection resulting from direct contact (through broken skin or mucous membranes) with the blood, secretions, organs or other bodily fluids of infected people, and indirect contact with environments contaminated with such fluids.

People are infectious as long as their blood and secretions contain the virus. Burial ceremonies in which mourners have direct contact with the body of the deceased person can also play a role in the transmission of Ebola. Healthcare workers in affected countries have frequently been infected through close contact with patients suffering from EVD when infection control measures are not strictly practised. Samples from patients are biohazardous and testing should be conducted under appropriate biological containment conditions.

How can you prevent it?

There is currently no registered vaccine for Ebola Virus Disease in Hong Kong. The best way to prevent the disease is to:

• Avoid unnecessary visit to affected areas.
  

• Observe good personal and environmental hygiene. Frequent handwashing with soap.
  

• Ensure thorough cooking of food before consumption.
  

• Avoid close contact with ill persons and avoid contact with blood and body fluids of infected people, including items that may have come in contact with an infected person’s blood or body fluids
  

• Avoid contact with animals.
  

How is it treated?

There is no specific treatment for the disease. Patients must be managed in isolation facilities to prevent the spread of the infection. Patients are frequently dehydrated and require oral rehydration with solutions containing electrolytes or intravenous fluids. As close contact with a severely ill patient is a high risk factor for transmission, health care workers should put on protective gears and adopt strict infection control practice when caring for suspected patient