Viruses are small infectious agents, made up of a piece of genetic material, such as DNA or RNA, enclosed in a coat of protein.

Viral Hemorrhagic Fevers, VHFs are caused by viruses of four distinct families: Arenaviridae, Bunyaviridae, Filoviridae, and Flaviviridae. Each of these families share a number of features:They are all RNA viruses, and are all covered, or enveloped, in a fatty (lipid) coating.Their survival is dependent on an animal or insect host, called the natural reservoir.The viruses are geographically restricted to the areas where their host species live.Humans are not the natural reservoir for any of these viruses. Humans are infected when they come into contact with infected hosts. However, with some viruses, after the accidental transmission from the host, humans can transmit the virus to one another.

How can cases of viral hemorrhagic fever be prevented and controlled?

With the exception of yellow fever and Argentine hemorrhagic fever, for which vaccines have been developed, no vaccines exist that can protect against these diseases. Therefore, prevention efforts must concentrate on avoiding contact with host species. If prevention methods fail and a case of VHF does occur, efforts should focus on preventing further transmission from person to person, if the virus can be transmitted in this way. Because many of the hosts that carry hemorrhagic fever viruses are rodents, disease prevention efforts include:

controlling rodent populations;
discouraging rodents from entering or living in homes or workplaces;
encouraging safe cleanup of rodent nests and droppings.
For hemorrhagic fever viruses spread by arthropod vectors, prevention efforts often focus on community-wide insect and arthropod control. In addition, people are encouraged to use insect repellant, proper clothing, bednets, window screens, and other insect barriers to avoid being bitten.

For those hemorrhagic fever viruses that can be transmitted from one person to another, avoiding close physical contact with infected people and their body fluids is the most important way of controlling the spread of disease. Barrier nursing or infection control techniques include isolating infected individuals and wearing protective clothing. Other infection control recommendations include proper use, disinfection, and disposal of instruments and equipment used in treating or caring for patients with VHF, such as needles and thermometers.

In conjunction with the World Health Organization, CDC has developed practical, hospital-based guidelines, Infection Control for Viral Haemorrhagic Fevers In the African Health Care Setting. The manual can help health-care facilities recognize cases and prevent further hospital-based disease transmission using locally available materials and few financial resources. https://www.medicinenet.com/