Ebola is one of the deadliest diseases on Earth, with a fatality rate as high as 90%. It’s among a handful of illnesses so dangerous that governments consider them threats to national security. An epidemic in West Africa that began in late 2013 and died down in 2016 killed more than 11,000 people, exceeding the counts from all previous waves combined. Worries are rising again.

1. What’s causing alarms?

A new outbreak in the Democratic Republic of Congo that began in August 2018 has infected more than 2,000 people and killed more than 1,300. Several cases were confirmed in neighboring Uganda in June, raising fears again of a wider contagion. Ebola disease is endemic to Congo, meaning it’s constantly present but generally under control. The International Federation of Red Cross and Red Crescent Societies says the latest outbreak has reached a tipping point, with as many as 20 new cases being reported each day, and efforts to combat it need to be drastically scaled up.

2. How’s that going?

Containment efforts have been hindered by a lack of health-care infrastructure and attacks by armed groups. The World Health Organization says security has improved since the start of 2019, giving response teams better access to affected communities. While the WHO has seen early signs that the number of new cases is slowing, it expects further waves of infections.

3. Where does Ebola come from?

Scientists say the virus that causes Ebola jumps to humans through contact with secretions from animals such as chimpanzees, gorillas and bats that are infected with it. The virus passes among people through direct contact with the bodily fluids of someone who is infected with the disease or has died from it. Medical workers and family members are the most at risk. Ebola doesn’t travel through the air, making it less easily transmitted than many other pathogens, as long as proper health-care practices are followed.

4. How does it affect people?

According to the WHO, symptoms of Ebola can include fever, fatigue, muscle pain, sore throat and headache, followed by diarrhea, vomiting and sometimes bleeding inside and outside the body. It damages the immune system and organs, leading to massive internal bleeding and death from multi-organ failure and shock.

5. Is it treatable or preventable?

There are no specific drugs for treating Ebola. Tackling symptoms early on increases the patient’s chances of survival. This includes administering fluids and body salts intravenously to prevent dehydration, providing oxygen, and using drugs to support blood pressure and control vomiting and diarrhea. An experimental vaccine produced by Merck & Co. has proved effective in human trials at fending off the disease. It has not yet been licensed anywhere, but Congo’s government has approved the drug for use in the face of the current outbreak.

6. How far could it spread?

A committee of the WHO determined in April that conditions for what it calls a Public Health Emergency of International Concern had not yet been met. In the previous big epidemic, Ebola spread from three epicenter countries -- Guinea, Liberia and Sierra Leone -- to Nigeria, Senegal and Mali. And, for the first time, Ebola infection occurred outside Africa. That provoked panic in the U.S. and Europe, but in all there were just 11 cases and one death from Ebola there.

--With assistance from William Clowes and Paul Richardson.

To contact the reporters on this story: Albertina Torsoli in Geneva at atorsoli@bloomberg.net;Mike Cohen in Cape Town at mcohen21@bloomberg.net

To contact the editors responsible for this story: Karl Maier at kmaier2@bloomberg.net, Andy Reinhardt, Paul Richardson

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