A group of infections that cause abnormal bleeding and may be fatal
Viral haemorrhagic fevers, which cause severe abnormal bleeding, occur predominantly in Africa. The only one native to parts of Europe and the US is Hantavirus infection. Marburg, Ebola, and Lassa fever occur only in localized outbreaks in Africa. There is a slight risk that travellers may be infected with the African haemorrhagic fevers and spread them to the developed world.
Hantavirus and Lassa fever virus are carried by rodents, and transmitted to people through contact with the animals’ urine, faeces, or saliva. Marburg fever virus is carried by monkeys; the animal carrier of Ebola fever virus is unknown. All are highly contagious and can be transmitted in body secretions.
Symptoms develop slowly from 1–3 weeks after infection and may include:
Rash, which causes peeling skin in Ebola fever.
Abnormal bleeding from the skin and mucous membranes.
The symptoms of viral haemorrhagic fevers vary from mild to severe depending on the specific virus; Lassa fever may be symptomless. Complications of Ebola and Marburg fevers include acute kidney failure, serious breathing difficulties, and shock.
Viral haemorrhagic fevers are diagnosed from the symptoms and a blood test. There are no specific treatments for Hantavirus infection, Marburg fever, or Ebola fever. However, Lassa fever may respond to antiviral drugs if given in the first week. The outlook depends on the type of virus and medical care available. Fatality rates vary from about 1 in 50 cases in Lassa fever to 9 in 10 in Ebola fever.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.