SciBar returns to the VAT & Fiddle and this month it’s Jonathan Ball talking about the virus du jour; Ebola. The title of the talk was, “Exposing Global Health Inequalities” so we knew that we’d be getting more than a brief review of the recent outbreak in Western Africa.
But first we get a history lesson. The first ever case of Ebola was discovered in Zaire in 1976. It was named after a local river rather than the village where it was discovered in order to protect its reputation. Before 2014, there had been fewer than 1,000 cases.
However, in the recent outbreak, there have been 24,872 cases resulting in 10,311 deaths (official figures produced the day of SciBar) Patient Zero was a two year old child in a village in Guinea. Within four months, there were 14 graves in the village, filled with Ebola victims.
Ebola is a filovirus and there are five species, four seen in Africa and one in South East Asia. These species range from the non-pathogenic Reston to the highly pathogenic Zaire. The virus naturally circulates in fruit bats and is also responsible for a massive die off of great apes in Africa.
There is an incubation period of around a week before symptoms begin to show and then it become contagious. Then victims tend to die between six and sixteen days after the symptoms begin to show.
The virus infects a monocyte and causes it to produce too much cytokine. This eventually leads to a massive lose of blood and fluid. The victim is then dehydrated and this can lead to organ failure. For reasons unknown, a victim having hiccups is a predictor of an impending death.
When the outbreak occurred in Western Africa, there was some discussion around how to deal with it. Would the tried and tested methods or prevention and control be employed or would some new, experimental drugs be used instead. As it stands, it’s been the tried and tested techniques that have been responsible for preventing the spread of Ebola.
However, some new treatments have also been developed. For example Zmapp, which was used on one of the Ebola patients that was brought back to the UK. To create it, they infect a mouse and then is converted for humans. Currently, they are looking at growing the vaccine inside a tobacco plant to reduce costs (by up to 10 times) Zmapp seems to be effective even after symptoms are showing.
An alternative drug is Favipiravir. This was originally developed to work on flu. It appears to work where there is a low viral load, reducing chance of death from around 30% to around 15%.
However, it’s very difficult to measure the efficacy of these drugs as standard double-blind tests can’t be used as it is considered unethical to give Ebola victims a placebo. However, there are still some questions to be answered about these new drugs:
How can you ensure supply in Africa?
How do we know that they have sufficient safety profiles?
What is the long term cost?
Do they actually work?
The big pharma players are also looking into Ebola vaccines. These have their own problems though. For example, one vaccine gives great short term protection but after a year, your chance of infection is 50%. How do you give a booster in Africa? There are questions about whether these vaccines effect current vaccines for TB and Malaria (both huge problems in Africa) since they all have similar bases.
So, vaccines are probably better suited for the west, especially since they require freezer storage. There is already a huge difference in survival rates between here and Africa. In the west, you have greater than a 70% chance of surviving Ebola. In Africa, you have greater than 70% chance of death.
Even with drugs like Zmapp, Ebola sufferers had to be given 35 litres of fluid daily. There’s just no way that you can do that in Africa. Meanwhile, when the outbreak started in Sierra Leone, there were more doctors at the Queen’s Medical Centre in Nottingham than in the entire country.
Jonathan ends his talk with the slightly depressing note that there will be another Ebola outbreak in the future.
It was a really interesting talk, Jonathan mixing a really accessible style with some more technical details – hearing about different types of vaccines was fascinating even if it was slightly over my head. He handled the two Q and A sessions really well.
In fact it was during these Q and A sessions that I learnt an amazing fact. While the current Ebola outbreak makes headlines around the world, the fact remains that more people die every year of flu than have EVER died from Ebola.
SciBar will return to the VAT & Fiddle at 7:30pm on the 29th of April. Professor Brigitte Nerlich is talking about, “What’s synthetic about synthetic biology – and should we worry about it?”