Viral Haemorrhagic Fever
Viral haemorrhagic fever (VHF) is a general term indicating a severe viral illness with fever and associated with internal/external bleeding (hence the name haemorrhagic fever).
VHFs occur worldwide but many are restricted to remote areas of Africa and South America. Several outbreaks occur each year, usually these are small, affecting <100 people . In 2014/16 the largest ever outbreak of the VHF Ebola occurred in West Africa; >28,000 cases were documented.
VHF is due to infection with a variety of different viruses, many of which also infect specific animals (particularly rodents and bats) and insects, i.e. Ebola virus, Marburg virus, Lassa fever virus, Crimean Congo Haemorrhagic fever virus , Yellow fever virus.
Depending on the particular virus, infection can be caught by:
Contact with blood/faeces/urine of infected animals
- This can occur due eating food contaminated by animal faeces/urine (or eating infected animals), or contact of damaged skin with animal faeces/urine or breathing in dust contaminated with infected animal/urine faeces e.g. Lassa fever, Ebola.
- Mosquito and Tick bites can transmit some of these viruses– e.g. Yellow fever, Crimean Congo Haemorrhagic fever.
Person to Person transmission
- Many of these viruses can be passed between people by contact with infected body fluids, or from objects contaminated by infected body fluids (e.g. medical equipment). This spread occurs particularly in health care settings that do not have, or do not adhere to strict appropriate infection control procedures e.g. Ebola.
Most infections with VHF cause no symptoms or may be mild. Symptoms usually start within 21 days of becoming infected. Most symptomatic cases start with a fever and flu-like symptoms that may be accompanied by diarrhoea and/or vomiting. In severe cases, symptoms rapidly worsen over days and internal and external bleeding can occur. There is a high fatality rate in severe cases
All people suspected of having a VHF should be treated in a specialist infectious diseases unit.
There is no specific treatment for VHF, but patients are given intensive care support if necessary.
VHF in travellers is extremely rare.
Those at highest risk include travellers to known VHF outbreak areas, especially medical personnel. VHF outbreaks are listed in the ‘News’ section on the individual country pages of fitfortravel.
Travellers to known VHF outbreaks must be aware of the risk of infection. They should seek advice from a travel health care practitioner prior to departure on avoiding transmission routes of the particular VHF. Only Yellow fever is vaccine preventable; no vaccines to prevent the other causes of VHF are available. In particular travellers should be aware of:
Medical personnel travelling to work in outbreak region must follow strict infection control guidance.
Travellers returning from tropical countries should always seek rapid medical attention if they develop flu-like symptoms (such as fever, headache, diarrhoea or general malaise) and mention to their health care provider that they have recently travelled.