What is Ebola and why is stopping the latest outbreak so difficult? 2 days ago Share Save Add as preferred on Google James Gallagher , Health and science correspondent , Emery Makumeno , BBC Africa, Kinshasa , Hafsa Khalil and Farouk Chothia Getty Images An Ebola outbreak in the Democratic Republic of Congo has been declared a public health emergency of international concern, by the World Health Organization (WHO). The latest outbreak is challenging because it involves a rare species of Ebola for which there is no vaccine, and the epicentre is in an area affected by conflict. What is Ebola and what are the symptoms? Ebola is a rare but deadly disease caused by a virus. Ebola viruses normally infect animals, typically fruit bats, but outbreaks among humans can sometimes start when people eat or handle infected animals. It takes two to 21 days for symptoms to appear. They come on suddenly and start like the flu or malaria, with fever, headache and tiredness. As the disease progresses, vomiting and diarrhoea develop and it can lead to organ failure. Some, but not all, patients develop internal and external bleeding. The virus spreads from one person to another by contact with infected bodily fluids such as blood or vomit. Ebola outbreaks used to be small and contained to remote rural areas. However, urbanisation is pushing larger populations closer to these natural reservoirs of Ebola and increasing the risk of transmission. Why is this Ebola outbreak different and is there a vaccine? This outbreak is caused by the rare Bundibugyo species of Ebola, which had not been seen for over a decade. Named after a district in Uganda where it was first detected, Bundibugyo has only caused two previous outbreaks – in 2007 and 2012. One study showed that it killed about a third of those infected, far less than the more common Zaire (66.6%) and Sudan (48.5%) species. Initial blood tests for Ebola in the affected areas were negative as they were designed to identify the more common species of the disease. There is no approved vaccine for Bundibugyo, but experimental ones are in development . It is possible that a vaccine for the Zaire species may offer some protection. There are also no drugs that target Bundibugyo, making it harder to treat. The WHO has recommended the evaluation – under strict protocols – of the experimental anti-viral drug obeldesivir, developed during Covid, to see if it is effective in stopping those who have been in contact with Ebola patients from getting sick. A further complication is that the outbreak is taking place in a conflict zone, with a quarter of million people displaced from their homes and people moving across porous borders into neighbouring countries. Trish Newport, from medical charity Doctors Without Borders, who is heavily involved in efforts to tackle the outbreak, told the BBC World Service that territory constantly changed hands between different armed groups, making it difficult for emergency response teams to simply drive to Ebola hot-spots. She pointed out that a further problem was bad roads, with a 90km (56-mile) journey from Bunia city to Mongbwalu, one of two gold-mining towns where the majority of cases have been reported, taking more than three hours. However, the WHO’s declaration of a public health emergency of international concern does not mean we are in the early stages of a Covid-style pandemic. The risk Ebola poses outside Central and East Africa is minimal. How health workers in DR Congo are treating Ebola and staying safe ‘Speed, money and compassion’ – lessons from an Ebola survivor and other experts How worrying is the Ebola outbreak in DR Congo? How did the current Ebola outbreak start? The first known case was a nurse who developed symptoms on 24 April, which means the virus had been spreading undetected for weeks. The nurse died in Bunia, the capital of eastern DR Congo’s Ituri province, according to Congolese Health Minister Samuel Roger Kamba. The victim’s body was repatriate