The virus spreads through the blood and is replicated in many organs. The histopathologic change is focal necrosis in these organs, including the liver, lymphatic organs, kidneys, ovaries and testes. The central lesions appear to be those affecting the vascular endothelium and the platelets. The resulting manifestations are bleeding, especially in the mucosa, abdomen, pericardium and vagina. Capillary leakage appears to lead to loss of intravascular volume, bleeding, shock and the acute respiratory disorder seen in fatal cases.
Patients die of intractable shock.
Those with severe illness often have sustained high fevers and are delirious, combative and difficult to control. The serologic method used in the discovery of Ebola was the direct immunofluorescent assay. The test is performed on a monolayer of infected and uninfected cells fixed on a microscopic slide. These tests may then be confirmed by using western blot or radioimmunoprecipitation. Virus isolation is also a highly useful diagnostic method, and is performed on suitably preserved serum, blood or tissue specimens stored at -70oC or freshly collected.