Ebola virus: What you need to know about the current outbreak

Ebola is far from new in Congo, but each appearance is still considered a crisis — one that needs to be quickly contained.

This most recent outbreak of the hemorrhagic fever, the ninth in Congo since the disease was identified in the 1970s, was first labelled an outbreak on May 8.

The disease can move from infected animals to humans who come into contact with contaminated blood. Ebola virus isn't airborne; instead, it moves from one person to another through contact with infected bodily fluids.

For people who contract Ebola, which has an incubation period of between two and 21 days, the fatality rate is high.

By the end of June, Congo's health ministry said that all the people it knew had been exposed to the virus had gone 21 days without showing any signs of the virus. If the country makes it to 42 days (two full incubation periods) without a new case of Ebola, officials can declare an end to the outbreak.

"The number of contacts requiring followup is progressively decreasing, with a total of 1,534 contacts having completed the mandatory 21-day followup period," the situation report from June 26 said.

Over the course of the outbreak, numbers for how many people had been sickened and died fluctuated. By June 26, WHO put the numbers at 55 cases and 28 deaths. Of the 55 cases, 38 were confirmed in a lab, 14 were probable and three were suspected.

In late May, WHO spokesperson Tarik Jasarevic said several factors, ranging from lab capacity to communication delays, can cause case numbers to change. Suspected cases that are later revealed to be negative for Ebola after lab tests are dropped from case counts, he said.

Where did it start and how far has it spread?

The current outbreak began in Bikoro, a small lakefront community in a rural area of Equateur province.

By mid-May, numbers were up and concern was mounting: cases of Ebola had been confirmed in Mbandaka, a sprawling city of more than a million people close to the Congo River.

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The river is a lifeline, essential for moving people and products through a massive country with weak infrastructure. But the river's role in daily life also raises the alarm for some health officials, since Congo's capital Kinshasa is downriver from Mbandaka.

Health officials didn't want to see the disease in Kinshasa. If the virus hit the densely packed city of more than 10 million, health teams would have to make a major push to find every case and curb Ebola's ability to spread.

As the push to fight the outbreak grew, local and international groups also took steps to make sure the virus didn't cross borders. A WHO spokesperson said teams were deployed to increase surveillance along the Congo River and at other points of entry.  

What's being done to contain the outbreak?

Dr. Oly Ilunga, Congo's minister of health, said in May that every local expert and resource available have been deployed to deal with the Ebola outbreak. But Congo's health system, once regarded as exemplary, has struggled after being starved for funding and support amid years of conflict.

This means every outbreak requires both local effort and substantial international support, and already there are concerns that not enough money has been pledged to meet the need.

WHO said the Ebola strategic response plan needed roughly $57 million US. The funding that poured in, while short of the goal, was bolstered by a $12-million pledge from the World Bank's new pandemic emergency financing branch, which is meant to swiftly move money into areas facing an outbreak.

Supplies and staff were sent to Congo, and organizations like Doctors Without Borders established isolation zones in treatment centres in Bikoro and Mbandaka. 

Is there a cure?

There's no known cure for Ebola, which means doctors and nurses are left to do what they can to treat the symptoms.

On June 4, however,  an ethics committee in Congo gave its approval for the use of five investigational treatments for Ebola under a compassionate use framework.

"This is the first time such treatments are available in the midst of an Ebola outbreak," WHO said in a statement. Clinicians on the ground will make decisions on which drugs to use. 

"The treatments can be used as long as informed consent is obtained from patients and protocols are followed, with close monitoring and reporting of any adverse events."

There is also a potential vaccine, which is being tested in Congo.

The Congolese government, with help from WHO and other partners, is testing the rVSV-ZEBOV Ebola vaccine. Canadian funding and work at the National Microbiology Laboratory in Winnipeg were essential to developing the vaccine, which is not yet licensed but has shown promise in clinical trials.

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The vaccine campaign has focused on front-line health-care workers and others who have had close contact with Ebola patients.

WHO said in late June that 3,268 people received the vaccination. Dr. Oly Ilunga, Congo's minister of health, said that so far none of the people who received the vaccine have developed the disease or experienced major side effects.

"The use of vaccination in this Ebola response has been a game-changer as it allowed us to break the chain of transmission and contain the virus more quickly," Ilunga said.

Dr. Peter Salama, deputy director of WHO, had previously told CBC's As It Happens that the ring vaccination method "was used in a trial a couple of years ago in Guinea to demonstrate that this vaccine, used with that strategy, can be 100 per cent effective."

The pharmaceutical giant Merck has a licensing agreement to develop the vaccine. If it works as researchers hope it will, Merck told CBC News in a statement, it will "make the vaccine available to the world's poorest countries at the lowest possible, not-for-profit price."