It is an extremely rare and lethal haemorrhagic fever, closely related to Ebola, for which there is no known cure.

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The death rate after haemorrhagic strokes was 25.5% in American hospitals but only 19.8% in OECD countries as a group.

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The severe form of the disease, dengue haemorrhagic fever, involves a high temperature, head and muscle aches, internal bleeding and, at worst, circulatory failure.

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Angola sealed its border with Congo to contain an outbreak of Marburg virus , an incurable Ebola-like haemorrhagic disease that has killed at least 146 people.

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However, when you look at just people under the age of 65, then haemorrhagic strokes become much more common - accounting for up to half of strokes.

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Within hours he was diagnosed with Crimean-Congo Haemorrhagic Fever, a virus nasty enough for him to be put onto a military transport aircraft for transfer to an isolation hospital in London.

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