UPDATED: Increasing concern over Ebola outbreak in West Africa

Is New Zealand prepared for Ebola? The growing number of Ebola virus disease cases in West Africa has made the current outbreak the largest ever recorded, and the risk of infection spreading by air travel has never been higher.

The latest update from World Health Organisation (WHO) estimates that as of 27 July 2014, the cumulative number of cases attributed to Ebola virus disease in West Africa stands at 1323 including 729 deaths.

African airlines and local authorities have put in place safeguards to prevent infected individuals travelling and potentially spreading the disease further afield.

Speaking to Stuff.co.nz, Dr Darren Hunt, The Ministry of Health’s Director of Public Health, played down any concern that Ebola would reach New Zealand, saying, “It is unlikely that New Zealand will have a case of Ebola virus disease because of our geographic isolation and the lack of direct flights to the affected countries. While the incubation period is two to 21 days, it is most commonly five to 10 days. Additionally, the affected countries are not common destinations for New Zealand travellers.”

According to the Ministry of Health Ebola symptoms include: sudden onset of fever, intense weakness, muscle pain, headache and sore throat symptoms. This is followed by vomiting, diarrhoea, rash, impaired kidney and liver function, and in some cases, both internal and external bleeding. Symptoms can take between two and 21 days to appear.

Although noting the risk of infection is low for those not in a health care setting, the Ministry has issued warnings to travellers: Avoid direct contact with blood and other bodily fluids of people with Ebola virus disease or unknown illnesses and to avoid close contact with or handling of wild animals.

In line with WHO reccomendations the government has not recommended travel or trade restrictions to affected areas.

The Ebola outbreak and the potential risk New Zealand to have been widely covered by the media in recent days. Examples include:

 

 

 

 

Our colleagues at the UK SMC collected the following expert commentary. Feel free to use these quotes in your reporting. If you would like to contact a New Zealand expert, please contact the SMC (04 499 5476; smc@sciencemediacentre.co.nz).

Prof Tom Solomon, Director NIHR Health Protection Research Unit in Emerging and Zoonotic Infections, and Professor at Institute of Infection and Global Health, University of Liverpool, said:

Q1: What is Ebola?

A1. “Ebola is a disease caused by Ebola virus.”

Q2. What are the symptoms?

A2. “The first symptoms of the disease are fever, severe headache, muscle aches, and abdominal pains. There are often small vesicle lesions in the mouth and at the back of the throat, which are associated with a very sore throat, and maybe pain down the throat and into the chest. The whites of the eyes may become red (called conjunctival injection), and patients may have diarrhoea and a skin rash. This is followed by bleeding (haemorrhage) which may occur from the mouth and other body orifices, for example bloody vomiting and bloody diarrhoea. This leads to a low blood pressure (known as shock) and the body’s clotting becomes completely disarrayed, and patient’s metabolism goes awry and they become acidotic. The brain can also be involved to cause convulsions and coma.  Deaths occur around the tenth day of illness. Death is usually caused by multiple organ failure, caused by dehydration, the abnormal metabolism and acidosis, rather than due to blood loss.”

Q3: How bad is it? (What does it do and what proportion of people die?)

A3. “Ebola is worrying because:-

a. it is not completely clear how humans become infected in the first place at the start of an outbreak

b. it can spread from human to human, as described above

c. The death rate depends on the subtype of Ebola virus; but it can be up to 90%, making it one of the most severe infections of humans”

 Q4: How does it spread?

A4. “Research suggests the virus exists naturally in some fruit bats, and that humans can become infected directly from the bats (perhaps through exposure to bat blood, or other bodily fluids excreta – faeces and urine).  Humans may also become infected by contact with blood or bodily fluids of moneys, or “bush meat”; i.e killing, butchering, and eating the meat of bush animals, that had presumably become infected from the bats.

“Once the first person has become infected, then others are at risk, because the virus is excreted in a patient’s blood and other bodily fluids. Family members and health care workers looking after patients are especially at risk. In the early outbreaks the lack of precautionary and protective measures and the reuse of non-sterilised needles contributed to the rapid spread.  Some traditional burial customs, whereby all mourners touch the body, also causes the virus to spread, because the virus may be on the skin.”

Q5: What can we do to treat it?

A5. “There is no antivirus drug to treat Ebola. However, if we can keep people alive through replacing lost fluids etc, by oral or intravenous rehydration, then this gives their body the best chance of fighting the infection itself. There is no vaccine to protect people.”

Q6: Should we be concerned that it’s going to spread like the swine flu pandemic?

A6. “The fact that this Ebola outbreak has spread more than any previous ones is worrying, and we are doing research to try and understand why this is. However, because it does not spread via the respiratory route (i.e. people coughing and sneezing on each other) it is unlikely to cause a pandemic like flu.”

Q7. Are people infectious before they show symptoms? How long are they infectious for?

A7. “Typically people are infected for 4-10 days before they start to show symptoms, though it can be as little as 2 days, and as much as 3 weeks. However, as far as we know they are unlikely to spread the virus until they start having the symptoms of bleeding, etc. If people survive the acute stages they may remain infectious for up to 2 months.”

Q8. Is this outbreak different to others and if so, how?

A8. “This outbreak is different to others in several respects. Firstly, it is larger than previous outbreaks. More than 670 people have died. Secondly, it appears to be spreading between different geographical places more easily than other outbreaks. So far it has spread from Guinea to Sierra Leon, Liberia, and now Nigeria.”

Q9: How can we detect whether someone has Ebola?

A9. “If someone has symptoms suggestive of Ebola, then we can test their blood for the virus, by detecting the virus itself, or looking for antibodies to the virus.”

Q10: How likely is it that Ebola will mutate into something that can spread more easily?

A10. “There is nothing to suggest this so far. The current outbreak is caused by Ebola Zaire strain, which is the most dangerous strain of the virus.”

Q11: What do people need to do to stop it spreading?

A11. “The risk of spread is reduced by people wearing protective clothing (barrier nursing) when they are looking after patients. The use of gowns, gloves, goggles and masks greatly reduce the chance of someone becoming infected. The risk of spread is greatest later in the disease when patients are bleeding. Diarrhoea, vomit, and blood from patients need to be decontaminated. The risk of respiratory spread, whereby virus is spread from one person breathing, coughing or sneezing on another is thought to be very low. When patients die they should be buried promptly, or cremated by specialist teams, to avoid the risk of virus being transmitted to mourners.”

Q12. What are researchers in the UK doing to protect us?

A12. “I lead the NIHR Health Protection Research Unit in Emerging and Zoonotic Infections which was established by the UK Government in April 2014 to help protect us from infections like Ebola. It is a collaboration between researchers from the University of Liverpool’s Institute of Infection and Global Health, the Liverpool School of Tropical Medicine, and Public Health England.  Members of the Health Protection Research Unit are currently helping to fight the Ebola outbreak in Africa, as well as doing research to try and better understand why this outbreak is especially bad. The Health Protection Research Unit’s virologists are doing research to understand what makes particular strains of Ebola more severe. The Unit’s epidemiologists and modelers are working together to understand the factors involved in its spread, and the risks to the UK.”

 

Prof Andrew Easton, Professor of Virology, University of Warwick School of Life Sciences, said:

“The first Ebola outbreak was in late 1976 and since then the advance in our knowledge and progress has been mixed. To date, including the current outbreak, there have been 3647 cases of infection in 24 separate incidents and 2262 deaths as a result of the infection – an overall fatality rate of 62%. The current outbreak with over 1200 cases is the largest seen and far exceeds the previous largest outbreak that involved 425 cases.  The mortality within outbreaks is very variable and has ranged from 25% (37 of 149 cases) to 90% (128 of 143 cases). The current toll of the West Africa outbreak is 672, though the number of cases and associated deaths continues to rise.  The consistently high mortality associated with Ebola virus disease reflects our lack of successful interventions with only supportive treatments being available.

“However, there have been some advances in Ebola virus research. We now fully understand the genetic makeup of the virus strains that have been associated with human infection. Five distinct strains have been identified, of which three have been associated with large outbreaks of Ebola virus disease. Modern diagnostic tools are available to rapidly identify Ebola virus, though access to these in the isolated rural areas of Africa remains problematic for financial and practical reasons. This is unfortunate because rapid diagnosis early in an outbreak is likely to reduce the impact of the infection.

“In terms of treatment there have been no significant advances at all. Our greater understanding of the route of transmission of the virus between people – through close contact with body secretions and infected blood – means that healthcare staff can take measures to reduce the risk of infection from the patients they are treating and family members can be alerted to the risks.

“Of particular note is the discovery that Ebola virus can persist for several weeks in patients who have recovered and are not presenting with any symptoms of disease. This provided a mechanism for the virus to reappear after an outbreak was apparently declining.

“Finally, we have a greater, but not complete, understanding of the natural animal host in which Ebola virus resides and from which it is introduced into human populations. While Ebola can infect many wild animal species fruit bats are the most likely source of transfer to humans. This knowledge led to the banning of sales of bats in markets in Guinea.

“The overall picture is that while we know a great deal about the virus we have a long way to go in providing effective and accessible prevention and treatment for those at risk.”

All the UK SMCs previous output on this subject can be seen here.

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