The deadly outbreak of the ebola virus in West Africa in February 2014 initially went largely unnoticed by the global media even though it is one of the world’s most frightening illnesses.
Cases were detected first in Guinea but quickly spread to neighbours Sierra Leone and Liberia and, having now claimed more than 1,000 lives and captured the attention of nations across the world, the main focus has tended to be on containment of the virus.
However, there are signs that research into the development of a drug to treat, or vaccinate against, ebola is making significant progress thanks to research being conducted by scientific teams around the world.
The World Health Organisation has reacted to the crisis by saying that largely untested drugs can be used on victims in West Africa given the severity of the situation and the need to bring it under control quickly.
Promising as some of the treatments may be, the outbreak has nevertheless brought into sharp focus the fact that drug research companies are first and foremost commercial entities that must ask themselves if tackling an illness prevalent in poor, under-developed countries with under-funded health services, makes commercial sense.
What is ebola?
At the heart of the debate is a virus which is terrifying because, up until now, there is no known cure and also because of the severity of its symptoms and the high rate of deaths in those infected – some estimates suggest that up to 90 per cent of those infected die. Others say it is at least 40 per cent.
The Ebola virus disease, which used to be called Ebola haemorrhagic fever due to the high level of bleeding, was named after the river in the Democratic Republic of the Congo where one of the first two villages to report cases in 1976 was located. The other was in Sudan.
Ebola is a viral illness that comes from direct contact with infected living or dead rainforest animals, including chimpanzees, gorillas, monkeys, fruit bats, forest antelope and porcupines, and can be passed from one human to another in blood and bodily fluids and secretions, but also beds, sheets, clothes or other surfaces that have come into contact with a sick person.
The early signs are sudden fever, intense weakness, muscle pain, headache and a sore throat. Vomiting and diarrhoea follow.
The kidney and liver are affected and there can be both internal and external bleeding, including from the eyes.
Patients are infectious once the symptoms show, which is two to 21 days after they have contracted the virus, but because of the lack of a cure or vaccine, containment has so far been seen as key to the strategy against ebola.
Containing ebola
Those suffering from the illness need intensive care, with intravenous fluids or oral rehydration salts and must be kept in isolation and their nurses and visitors must wear full protective suits.
Care can include:
• Good nursing care
• Oxygen and devices that help with breathing
• Intravenous fluids to maintain fluids and electrolytes
• Medications to control fever, help the blood clot, and maintain blood pressure
• Antibiotics to prevent secondary infections.
For health professionals treating outbreaks, viewed as one of the highest at-risk categories of infection, it is also important to focus efforts on the community where the outbreak began. In the past, that has usually been villages in close proximity to rainforests.
The big concern for nations outside West Africa is the capacity of ebola to spread across the world, the risk of which rests with the time it takes between infection and noticeable symptoms, meaning that somebody with the virus could theoretically get on a plane and spark an outbreak – probably in a hospital – anywhere in the world.
Virologist Dr Ben Neuman, of the University of Reading in the UK, said: “The virus can spread person to person but requires direct contact with the body fluids of an infected individual or corpse. This virus is not transmitted by the respiratory route – you cannot catch ebola as you would the flu.
“While it is possible in theory to transmit ebola fever sexually, usually the virus is spread to family members and hospital staff who tend the sick. The other common route for infection is at public open casket funerals of ebola victims.”
Containment can be very effective, according to Dr Tim O’Dempsey, a senior Lecturer in Tropical Medicine at the Liverpool School of Tropical Medicine (LSTM) in the UK, who has been a key part of the WHO response and spent a month in Sierra Leone earlier this year.
LSTM clinical staff routinely manage critically ill patients at the Tropical and Infectious Disease Unit at the Royal Liverpool University Hospital and Dr O’Dempsey said: “The issue in West Africa is one of poorly resourced health systems.
“Our experience in Sierra Leone was that if health services were properly resourced, with correctly trained medical staff, between 40 and 60 per cent of people who present with the symptoms can survive.
“We were finding that adopting the right infection control systems was allowing us to make a difference.
“We know how to treat ebola. The key is using the right procedures and good communication but the outbreak in West Africa has revealed weak health systems and, if you become ill and know that your local health centre is under-resourced, you are unlikely to go there.
“The truth is that this illness is treatable. The figures for 90 per cent death rates relate, I think, to earlier outbreaks and are frightening but our experience is that death rates can be lower than that.”
During the latest outbreak, world governments have tried to help minimise that risk of the virus spreading outside West Africa.
The UK Department for International Development, for example, announced a £2m aid package to partners, including the International Federation of the Red Cross and Médecins Sans Frontières that are operating in Sierra Leone and Liberia. The European commission said it would allocate an additional €2m (£1.6m) to help contain the spread of the disease.
Dr Neuman believes that such an approach will help because of inherent weaknesses in the virus.
He said: “There is a possibility of ebola coming to the UK but it’s very unlikely. The virus remains very weak, fragile, and transmits very inefficiently.
“Ebola is spreading in West Africa among a mostly rural population due to a lack of trust and education about medical intervention – that does not exist in the UK.
“We also have a massive infrastructure in place to prevent diseases like ebola from coming to Britain – highly trained people, equipment and technology that will be mobilised if a case arrives. One reason that we haven’t heard more about similar diseases in the past is because our public health workers are good at their jobs. There is virtually no risk to the general population.
“The World Health Organisation declaring a public health emergency of international concern is a big forward step in the fight against this dangerous disease. It is a rare event, something only done in the past for H1N1 ‘swine‘ flu in 2008 and the ongoing polio outbreak.
“This will make the vast resources of the United Nations such as funds, experts and equipment, available to help stop ebola. This should bring the outbreak under control although it’s likely it won’t be stopped completely until after Christmas.
“The WHO also recommended commonsense procedures to stop the spread of infection, such as taking temperatures of incoming passengers from airports in the affected region.
“Educating and gaining the trust of the people likely to be infected are key to preventing future outbreaks.”
Can a drug treatment be found?
Running alongside containment has been work on a drug-based treatment. For example, Canadian company Tekmira Pharmaceuticals Corporation recently announced that the US Food & Drug Administration (FDA) has allowed the potential use of its drug TKM-Ebola in individuals infected with ebola.
TKM-Ebola, an anti-Ebola virus RNAi therapeutic, is being developed under a $140 million contract with the US Department of Defense’s Medical Countermeasure Systems BioDefense Therapeutics Joint Product Management Office.
Earlier preclinical studies demonstrated that when the drug was used to treat previously infected non-human primates, the result was 100 per cent protection from an otherwise lethal dose of Zaire ebola virus.
Dr Mark Murray, CEO and President, Tekmira Pharmaceuticals, said: “We have been closely watching the ebola virus outbreak and its consequences and we are willing to assist with any responsible use of TKM-Ebola.
“This current outbreak underscores the critical need for effective therapeutic agents to treat the ebola virus. We recognise the heightened urgency of this situation and are carefully evaluating options for use of our investigational drug within accepted clinical and regulatory protocols.”
For Dr Neuman, at the University of Reading, economics remain a stumbling block. He said: “Pharmaceutical companies are businesses – they last only as long as they continue to make money.
“While a new wonder-drug may be hugely profitable in the short-term, the financial health of a company depends on its drug development pipeline, the ability to bring a steady flow of new drugs to the market in the long term. A company is only as strong as its pipeline.
“The potential ebola medications that are being considered all work well at stopping the virus in the lab and in infected animals. A person with ebola might have to be treated for a month or more and the side effects of large amounts of treatment over a long time are tough to predict.
“There are reasonably strong humanitarian and ethical grounds to allow experimental ebola therapies for infected people.”
Dr O’Dempsey, at Liverpool, said: “There are several considerations with the drugs being developed, both the treatments being developed, and the vaccine being developed in Canada.
“There are ethical issues with using drugs that are not fully tested. Who do you give them to, will they work, will they do harm?
“There is also a dilemma for companies developing drugs for a range of tropical diseases. Usually they will be used to benefit poor people and there is little commercial gain to be achieved in developing them for such markets.”
