Ebola - you're never likely to see it but we can't ignore it
Ebola isn't new - the first confirmed outbreak was in the Democratic Republic of Congo in 1976, with 318 confirmed cases. The current outbreak is the 24th since then, but from 1979 to 1994 there were no reported cases worldwide. It also isn't easy to catch - unlike other viruses, it can't be spread through droplets in the air, so you can't catch it just by being in the same room as someone. Infection comes from direct contact with an infected person's bodily fluids.
The virus is thought to have originated in fruit bats, where it lives harmlessly. From here it spread to other forest animals like chimpanzees and gorillas, and on to humans after they butchered and ate these animals as 'bush' meat. Every new outbreak has started in an African country (most commonly Democratic Republic of Congo, Uganda or Sabon), and never before has it spread outside Africa.
But the last few months' health stories have been dominated by stories on Ebola, and the occasional good news recovery stories have been few and far between. This week, the first person to be diagnosed with Ebola in the USA was announced, although he had caught the disease in Liberia, where he had been until a few days earlier. Only a few days before that came the end of a three-day national shutdown of an entire country in an attempt to halt the spread.
Save the Children announced yesterday that there are five new cases of Ebola every hour in Sierra Leone alone, and this figure could rise to 10 an hour by the end of the month. So far in this outbreak there have been 7,178 confirmed cases, mostly in Sierra Leone, Liberia and Guinea.
The virus has an incubation period of two to 12 (most commonly five to seven) days once a person is exposed to it. After that, symptoms include high fever, joint pain, vomiting and diarrhoea, muscle pain and intense weakness, sore throat and stomach pain. They begin to bleed internally, and kidneys and liver can fail.
There are lots of reasons why Ebola is much more likely to take hold in an African country than a Western one once first cases are seen. Overcrowding increases the risk of spread of any infection; malnutrition raises the risk of dying from it (millions of children in Africa still die today from diseases like measles). The tradition in many African communities of touching a body after death during the mourning process passes on the infection - the virus can survive on the skin for several days after death.
And while the mortality rate during this outbreak, at about 70%, is lower than the 90% seen in the worst cases, access to hospital care and intravenous fluids can help recovery. Equally important, hospital isolation and strict infection controls during treatment dramatically curb the likelihood of other people being affected. Last week alone Sierra Leone saw 765 new cases, and it only has 327 hospital beds - this standard of care is not an option.
So, is the NHS, already struggling under the burden of an ageing population, likely to crack under a nationwide Ebola epidemic? Not in my lifetime. But for millions in less fortunate developing countries, the nightmare is already here. The Ebola Donors Conference, jointly hosted in London by the UK and Sierra Leone government this Thursday, is already too late for many.