Viral hemorrhagic fevers (VHFs) are a group of illnesses known to be caused by four families of viruses. The families include the Ebola, Marburg, Lassa fever, and yellow fever viruses. Viral hemorrhagic fevers have common features, and they affect many organs. They damage the blood vessels, and in the process, affect the body’s ability to regulate itself.
Some Viral hemorrhagic fevers cause mild disease, but some, like Ebola or Marburg, cause severe disease and can lead to fatalities.
Viral hemorrhagic fevers are found around the world, but specific diseases are usually limited to areas where the animals that carry them live. Lassa fever incidences, for example, is common to rural areas of West Africa where rats and mice carry the virus.
Viral hemorrhagic fevers (VHFs) are spread by contact with infected animals, people or insects, and no current treatment can cure viral hemorrhagic fevers. However, immunizations exist for only a few types, and until additional vaccines are developed, the best approach is prevention.
Some viral hemorrhagic fevers include dengue, Ebola, Lassa, Marburg, and yellow fever.
Viral Hemorrhagic Fever (VHF) Facts
Viral hemorrhagic fevers are a group of illnesses caused by different families of viruses that cause vascular damage, resulting in symptomatic bleeding (hemorrhage).
For example, Arenaviridae cause Lassa fever, Argentine hemorrhagic fever and Bolivian hemorrhagic fever (Machupo virus). Filoviridae cause Ebola and Marburg diseases, while Flaviviridae cause yellow fever, dengue fever, Omsk hemorrhagic fever, and Kyasanur Forest disease.
Hemorrhagic fever viruses are mainly zoonotic diseases caused by viruses that usually reside in animal or arthropod hosts, and if the virus is introduced accidentally to humans in cities, it may become widespread (for example, the Ebola outbreak).
The viruses can be transmitted to humans when humans come in contact with the urine, feces, saliva, or other bodily fluids of infected animals or arthropods, including if the animal is killed and eaten.
It has been known that in some instances, once the viruses infect humans, person-to-person transmission becomes possible.
Symptoms Of Viral Hemorrhagic Fever
Symptoms of VHF include fatigue, fever, weakness, dizziness, and muscle aches. The more severe cases of the infection show bleeding under the skin, internal organs, or even from bodily orifices like the mouth, eyes, or ears.
Some patients may also develop severe diarrhea that may also be bloody, and suffer shock, delirium, seizures, kidney failure, and coma that often are fatal.
There is no other established cure for viral hemorrhagic fevers, but treatment with convalescent-phase plasma has been used with success in a few patients. Other experimental antiviral agents have also been applied and used on a few test patients, but prevention efforts are concentrated on avoiding contacts with the host species, vectors, or humans infected with the viruses.
Symptoms of viral hemorrhagic fevers vary by disease, however, common symptoms may include:
- High fever
- Muscle, bone or joint aches
- Symptoms can become life-threatening, and may cause bleeding.
- Liver failure
- Nervous system malfunctions
- Kidney failure, and
- Respiratory fever
The viruses that cause viral hemorrhagic fevers live naturally in a variety of animal and insect hosts like mosquitoes, ticks, rodents or bats.
Each of these hosts typically lives in a specific geographic area, so each particular disease usually occurs in geographic locations where their virus’s host normally lives. Some viral hemorrhagic fevers also can be transmitted from person to person and can spread if the infected person travels from one geographic area to another.
The route of transmission varies by the specific virus, because, while some viral hemorrhagic fevers are spread by mosquito or tick bites, others are transmitted by contact with infected blood or semen. A few strands can be inhaled from infected rat feces or urine.
It can take up to 21 days for symptoms to manifest.
Preventing viral hemorrhagic fevers has its own challenges, and many of the social, economic and ecological factors that contribute to the sudden appearance and spread of infectious diseases are problems that have no easy solutions.
If you travel to areas where viral hemorrhagic fevers are known to be common, take precautions to protect yourself from infection, and use appropriate protective barriers such as gloves, eye and face shields.
Precautions also may include:
- Careful handling and management of disinfection, and disposal of laboratory specimens and waste.
- Get vaccinated
- Avoid mosquitoes and ticks
- Guard against rodents, and keep pet food covered and stored in rodent-proof containers.
- Dispose of garbage on a regular basis.
- Place woodpiles and stacks of bricks many feet from your house.
- Mow your grass closely and
- Keep the bush within 100 feet from your house trimmed.