Ebola – Emerging Disease

Ebola virus disease (EVD), formerly known as Ebola hemorrhagic fever, is a severe, often fatal illness in humans.

The virus is transmitted to people from wild animals and spreads in the human population through human-to-human transmission.

The average EVD case fatality rate is around 50%. Case fatality rates have varied from 25% to 90% in past outbreaks.

The first EVD outbreaks occurred in remote villages in Central Africa, near tropical rainforests, but the most recent outbreak in West Africa has involved major urban as well as rural areas.

Community engagement is key to successfully controlling outbreaks. Good outbreak control relies on applying a package of interventions, namely case management, surveillance and contact tracing, a good laboratory service, safe burials and social mobilization.

Early supportive care with rehydration, symptomatic treatment improves survival. There is yet no licensed treatment proven to neutralize the virus but a range of blood, immunological and drug therapies are under development.

There are currently no licensed Ebola vaccines but 2 potential candidates are undergoing evaluation.

The last outbreak from West Africa, (March 2014), was the largest and most complex Ebola outbreak since Ebola was discovered in 1976. There were more cases and deaths in this outbreak than all others combined. It also spread between countries starting in Guinea then spread across land borders to Sierra Leone and Liberia, by air (1 traveler) to Nigeria and USA (1 traveler), and by land to Senegal (1 traveler) and Mali (2 travelers).

Fruit bats of the Pteropodidae family are natural Ebola virus hosts. Ebola is introduced into the human population through close contact with the blood, secretions, organs or other bodily fluids of infected animals such as chimpanzees, gorillas, fruit bats, monkeys, forest antelope and porcupines found ill or dead or in the rainforest.

All Ebola survivors and their sexual partners should receive counselling to ensure safe sexual practices until their semen has twice tested negative. Survivors should be provided with condoms.

Male Ebola survivors should be offered semen testing at 3 months after onset of disease, and then, for those who test positive, every month thereafter until their semen tests negative for virus twice by RT-PCR, with an interval of one week between tests.

Ebola survivors and their sexual partners should either:

abstain from all types of sex, or

observe safe sex through correct and consistent condom use until their semen has twice tested negative.

Symptoms

Incubation: 2 to 21 days

Humans are not infectious until they develop symptoms. First symptoms are fever, fatigue, muscle pain, headache, and sore throat. Followed by vomiting, diarrhea, rash, impaired liver and kidney function, and in some cases, internal/external bleeding (oozing from gums, blood in stool). Low white blood cell and platelet counts and elevated liver enzymes.

It can be difficult to distinguish EVD from other infectious diseases such as malaria, typhoid fever and meningitis.

 

 

 

Citation

Ebola virus disease. (n.d.). Retrieved May 03, 2017, from http://www.who.int/mediacentre/factsheets/fs103/en/