The worst-ever Ebola outbreak began in December 2013 and spanned for 3 years. There were 29,000 cases, resulting in 11,300 deaths. It started in southern Guinea before spreading to Liberia and Sierra Leone.

Now the virus has returned in the Democratic Republic of the Congo, and since 4 April there have been 30 possible cases with two being confirmed as Ebola.

This latest suspected outbreak is in Bikoro, a small market town in the Équateur Province in the DR Congo, where 18 people have died. The World Health Organisation (WHO) and the DR Congo government have already sent help in the form of health experts from WHO, Médecins Sans Frontières and Provincial Division of Health.

At this stage, it is very difficult to tell what impact this latest outbreak will have, as although there have only been a couple of confirmed cases, it may have already spread to other parts of the country. Whilst the Bikoro region is in a relatively remote area, it also has a port on lake Tumba which is connected to the Congo and Ubangi rivers.

This is not the first time DR Congo have had to deal with an outbreak. In fact, aside from the epidemic from 2014-16, there have been 24 outbreaks in Western and Central Africa, 9 of which have been in DR Congo.

It’s thought that if the situation is handled quickly, then the disease can be contained. For example, around the same time last year, an outbreak was contained in Bas-Uele province in the country's far north.

How is Ebola transmitted?

Ebola is a viral disease, which is thought to originate from fruit bats who host the virus. It can be transmitted to humans through contact with the bodily fluids of infected animals (blood, saliva, urine, mucus and sweat secretion). It can then spread among humans through contact with the bodily fluids of infected people, and the surfaces and materials that they may have contaminated.

According to WHO, the average fatality rate is around 50%. The worst single outbreak was part of the 2014-16 epidemic, where the fatality rate was 67% from 3811 cases in Guinea.

Initially the symptoms are similar to that of a fever (muscle pain, headache and sore throat). This is then followed by vomiting, diarrhoea and the appearance of a rash. It can also impair function of the liver and kidneys, and cause internal bleeding in some cases.

The incubation period for Ebola is between 2 and 21 days and for fatal cases. It takes between a few days and two weeks for the disease to kill someone. Recovery from Ebola is a long and arduous process. It can lead to hair loss, hearing loss and other sensory changes; this is often described as post-Ebola syndrome. It has also been discovered that Ebola can live in other parts of the body, even if the blood has been found to be virus-free.

How is Ebola diagnosed?

Diagnosing Ebola can be a difficult process as it is not easily distinguished from other infectious diseases such as malaria, typhoid fever and meningitis. However, Ebola symptoms can be determined through a number of diagnostic tests; automated or semi-automated nucleic acid tests (NAT) are the most common.

Ebola is not just dangerous due to the ease with which it can be transmitted; it is also an extreme biohazard risk when samples are being collected from humans. Furthermore, burial ceremonies can also provide the risk of transmission as the disease is infectious as long as it is in the blood stream.

There are currently five known strains of Ebola, the deadliest and latest of which is the Zaire strain. A vaccine has been developed for it and even though it has not yet been licensed, there are over 300,000 doses available to use should they be necessary.