Should we be worried about an Ebola outbreak in the UK?

http://www.theguardian.com/commentisfree/2014/jul/30/ebola-outbreak-uk-no-treatment-hard-to-catch

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The current Ebola virus outbreak is by far the largest so far. The first recorded cases were in 1976 in the Democratic Republic of the Congo and in southern Sudan. In the current west African outbreak in Guinea, Sierra Leone and Liberia (with one case imported into Nigeria), more than 670 people have died and there have been more than 1,200 cases. Only three previous outbreaks had more than 200 deaths; in the DRC in 1976 there were 280, with another 250 lives lost there in 1995, while 224 people died of Ebola in Uganda in 2000-1.

The virus takes its name from the Ebola river at Yambuku, in the DRC, where the 1976 outbreak occurred. This was particularly deadly in that the mortality rate was 88%. Most outbreaks have not been quite so lethal, with about 60% being the norm. But for any infection this is staggeringly high. Smallpox rightly engendered fear and panic but in its most lethal form only killed 25%.

Ebola’s natural home is probably fruit bats. Hunting them for food has been found to be the cause of human infections, but quite often it has been impossible to find how the first case in an outbreak got infected. Contact with dead monkeys, particularly chimpanzees, has also started outbreaks, and the virus has caused epidemics in gorillas.

Once human infection starts Ebola grows very rapidly in cells and kills them, in particular those that are important in regulating the immune system. In consequence it runs wild. Natural antiviral defences are shut down while the inflammatory response goes into catastrophic overdrive, causing more cell damage, blood pressure collapse and eventually heart failure. Blood clotting goes wrong, the liver and adrenals fail, and blood vessels leak. The end result is shock like that caused by an overwhelming bacterial septicaemia. One big difference is that if the infection is bacterial, the patient might be brought back from the brink by antibiotics, which is not an option for an Ebola infection. There is no specific treatment. All that can be done is trying to keep the blood pressure up and restore the fluid balance.

Diagnosis is not easy at the beginning of the illness, because its symptoms are the same as those that are seen in many other infections, including fever, headache, aching muscles, tiredness, sore throat, nausea, vomiting, abdominal pain and diarrhoea. So if someone is infected and then travels to the UK before the illness develops (which usually happens five to 12 days after exposure), Ebola could be mistaken for more common conditions like malaria or food poisoning. Later the patient may develop a rash, and start to bleed from the nose, ears, eyes, gums and in the stomach. Some go blind, and have uncontrollable hiccups. These symptoms point to a lethal outcome.

The only good news is that Ebola is quite hard to catch. Close contact with the body fluids of an infected person is needed. The virus does not spread on the wind. Burial practices involving the washing of corpses has led to the spread of infection and carers of those infected in a domestic setting (without the use of isolation units and protective suits) have a 10-20% chance of catching the virus.

Is the UK at risk? The likelihood of an infected person travelling to the UK is very low and we have good diagnostic and isolation facilities, if needed. The most important control measure is for healthcare workers, who are the first port of call for someone who might have the disease, to ask possible cases where they have been in the last three weeks.