Viral hemorrhagic fevers (VHFs) such as Ebola and Marburg virus make headline news because they are dangerous, contagious diseases. Other VHFs include:
- Lassa fever
- Hantavirus
- Rift Valley fever
- yellow fever
- Dengue fever
- Omsk hemorrhagic fever
- Scandinavian nephropathia epidemica
What symptoms do VHFs have?
VHFs are a diverse bunch, but some common symptoms are:
- raised temperature
- muscle pain
- gastro-intestinal symptoms such as vomiting, diarrhea
- a rash or purple or red spots
- flushed face
- unusual bleeding or unexplained bruising
- low blood pressure and shock
If you think you or someone you are caring for has a VHF, get medical advice immediately.
How are hemorrhagic fevers spread?
The viruses that cause VHFs are diverse in nature and are transmitted in a variety of ways.
For example, yellow fever and Dengue fever and Rift Valley fever are spread by mosquitoes, and Omsk hemorrhagic fever can be acquired from a tick bite. Lassa fever is contracted from the urine of infected mice and rats. Other VHFs spread via respiratory droplets.
The virus that causes Ebola, one of the most deadly VHFs, can be contracted by touching an infected person or their bodily fluids. It is also sexually transmitted, and can be contracted from eating undercooked bushmeat (the meat of wild African animals).
Are there hemorrhagic fevers where I am going?
Unfortunately, VHFs occur all over the world, though some are fairly localized. Fortunately, the risk is low for most travellers.
Your travel health adviser will have access to up-to-date information about the areas you are travelling to, and can tell you whether any outbreak warnings have been issued. You can use this information to adjust your itinerary and activities as necessary. You may also find outbreak information in the travel advisories issued by the Government of Canada.
Are you travelling as a healthcare or voluntary worker? Your risk of exposure to VHFs may be elevated. The organization you are working with will issue VHF guidelines if necessary.
How dangerous are hemorrhagic fevers?
Though some VHFs are mild, for example Scandinavian nephropathia epidemica, others can be fatal in the majority of cases, particularly if they are not identified and treated swiftly. A diagnosis can be hard to obtain, particularly once you get back to home as Canadian healthcare professionals may not be expecting to see a disease that only occurs, for example, in a small region of rural Africa. There are few effective treatments for VHFs: care is mainly supportive.
Can I protect myself from hemorrhagic fevers?
You can get vaccinated against one VHF: yellow fever. And you need to get a certificate of vaccination against yellow fever before you can enter some countries. The yellow fever vaccine and certificate can only be obtained from registered yellow fever vaccination centres. Your travel health adviser can tell you whether you should get this shot.
The usual travellers’ health precautions will also help prevent exposure to VHFs. These include:
- avoid insect and mosquito bites
- take care over food and water hygiene
- practise good hand hygiene
- do not touch dead or sick animals
- take local advice about quarantine zones
- avoid mass gatherings if you know an outbreak has occurred recently
If you develop a feverish illness on your return from a region where VHFs occur, you should seek medical advice and let the doctor know where you have been.