In a fatal attack, however, it manifests very quickly. In a number of cases, death has occurred within 24 hours of the onset of the infection,[2] while other cases do not last longer than around five days.[6] The virus attacks endothelial cells, rupturing capillaries and causing blood loss and haemorrhaging; once this reaches the heart, the haemorrhage kills quickly through shock. Symptoms include lethargy and an unwillingness to eat, a rapid heartbeat, and decreased blood-cell count, as well as cyanosis of the tongue, mouth ulcers, and oedema of the head and trunk.[6]