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Magill’s Medical Guide, 9th Edition

Viral hemorrhagic fevers

by Dennis Wang., MD , MPH

Category: Disease/Disorder

Anatomy or system affected: All

Specialties and related fields: Epidemiology, virology

Definition: Acute zoonotic diseases caused by viruses.

Key terms:

epidemiology: the study of the occurrence, frequency, causes, and distribution of diseases within a population

hemorrhagic: referring to a disease or disorder characterized by abnormal bleeding, often from internal organs, although bleeding may also occur under the skin, in the mucous linings of the nose and throat, and in tear ducts

reservoir species: animals that can carry a virus or bacterium that causes a disease in other species without suffering serious or fatal illness themselves

zoonoses: disorders carried by animal hosts that can be transmitted to humans

CAUSES AND SYMPTOMS

Viral hemorrhagic fevers are caused by a variety of viruses, including members of the Arenaviridae, Bunyaviridae, Flaviviridae, and Filoviridae families, with the last mentioned being the one associated with diseases such as Ebola hemorrhagic fever and Marburg hemorrhagic fever. Many of the hemorrhagic diseases are zoonoses that exist in reservoir species, such as bats, and are transmitted to humans through various modes; others are vector-borne. Crimean-Congo hemorrhagic fever, for example, is carried by ticks; humans become infected when they are bitten. In contrast, Ebola hemorrhagic fever, caused by a filovirus, is suspected of making the leap from animals to humans through the handling and eating of infected wild game, while Lujo fever, which is caused by an arenavirus, apparently infects humans when they inhale dust from rodent droppings. However, some viral hemorrhagic fevers may have the ability to aerosolize and thus may be transmitted person-to-person from an infected patient to caregivers or family members when an infected person sneezes or coughs. Contact with body fluids, such as blood or vomit, from an infected person can also cause the disease to spread.

The initial clinical signs and symptoms for viral hemorrhagic fevers are like those of many common illnesses, such as influenza or dysentery, with the patient complaining of a fever, headache, generalized aches and pains, or nausea. In the case of Ebola hemorrhagic fever, clinical signs may include a skin rash or red eyes. It is usually not until several days after the onset of the illness that the hemorrhagic signs, such as bloody diarrhea indicating internal bleeding, appear. Because the symptoms for many hemorrhagic fevers are like those of common tropical diseases, initial diagnosis and quarantine efforts may be delayed.

The virulence of the hemorrhagic fevers varies, depending both on the specific viral strain involved and how quickly medical treatment is obtained. Despite the name hemorrhagic fever, it is rarely the blood loss associated with the diseases that causes death but instead the failure of organs such as the kidneys. Some Ebola hemorrhagic fevers have resulted in death rates of close to 90 percent of infected patients, while others have been as low as 20 percent. Similarly, incubation periods vary for the different diseases, from only a few days for some diseases to as long as three weeks for others. The best-known hemorrhagic fever, Ebola, has an incubation period of two to twenty-one days.

Information on Viral Hemorrhagic Fevers

Causes: Viral infection

Symptoms: Fever, sore throat, generalized body aches, headache, vomiting, diarrhea, rash, red eyes

Duration: Varies depending on specific disease, from few days to several weeks

Treatments: Primarily supportive care to minimize suffering and alleviate symptoms

Most epidemics of hemorrhagic fevers have occurred in the developing world, with some of the most notable recent instances in sub-Saharan Africa, where basic public health infrastructure and access to medical care remain poor, and where patterns of migration and multigenerational housing have led to rapid transmission, delayed detection, and higher mortality rates. During the 2014 West African Ebola outbreak, aid workers who contracted Ebola and were immediately evacuated back to the United States for experimental therapies, such as convalescent serum and antibody cocktails as well as supportive care, had significantly higher rates of survival.

TREATMENT AND THERAPY

Treatment for viral hemorrhagic fever varies from disease to disease. In many cases, the only care that can be given is that of relieving the suffering of the patient by treating the symptoms—giving liquids intravenously to replace fluids lost through vomiting or diarrhea, trying to keep electrolytes balanced, and giving drugs that may reduce the patient’s fever or body aches. In some cases, patients have been successfully treated with blood transfusions from persons who have survived a similar illness to transfer protective antibodies from one patient to another. Similarly, concentrates of antibodies are also under investigation for the treatment of Ebola.

Because the exact transmission routes for many hemorrhagic fevers remain unclear, once patients are diagnosed, a strict quarantine must be instituted, with health care workers and family members alike wearing protective clothing to prevent becoming contaminated with any infectious material. Health workers in both developing and developed nations have previously been infected while caring for patients with hemorrhagic fevers. When a patient dies, the body must also be handled carefully. In the case of Ebola, the World Health Organization (WHO) recommends burial or cremation as quickly as possible following death.

Viral hemorrhagic fevers that emerge from the developing world certainly have the potential to threaten those in developed nations as well, though historically, cases in the United States have been limited to returning travelers and aid workers rather than local transmission. The outsized attention to these tropical diseases, however, have on the one hand fueled public fear and in some cases racialized profiling, but on the other also promoted investments in vaccine and therapeutics research and highly secure laboratories as well as containment units for the treatment of contagious individuals.

PERSPECTIVE AND PROSPECTS

As the population has expanded globally and humans have encroached upon formerly isolated wildlife habitats, more viral hemorrhagic fevers have been discovered, sometimes through the case of just one or two persons becoming infected by a previously unknown pathogen and sometimes through devastating outbreaks resulting in many deaths. The 2014-16 West African Ebola outbreak was the deadliest on record, affecting tens of thousands and killing more than 10,000 people. That and the 2018-20 Kivu Ebola outbreak made up two of only four “Public Health Emergencies of International Concern” declared by the WHO during the 2010s.

Despite many years of research, many of these diseases remain scientific mysteries.

The best-known example, Ebola hemorrhagic fever virus, exists in multiple locations in Africa. Some strains are comparatively mild; some are extremely virulent, spreading quickly and causing high numbers of deaths within a population. Researchers now know that, as is true with many viruses, patients who have been infected by Ebola and survive retain antibodies to that strain of virus for decades.

Though theoretically possible to develop vaccines and therapeutics for viral hemorrhagic diseases, several factors mitigate such work. First, is the reality that although many can be quite devastating in terms of death rates, outbreaks that have occurred to date have been in remote areas or have affected exceptionally low numbers of persons. It is easy to argue for funding vaccine research work when a disease is widespread, as in the historical example of polio; it becomes much more difficult for researchers when the disease in question is localized in nonindustrialized countries such as in sub-Saharan Africa. Second, low case counts have limited the ability to demonstrate the effectiveness of novel therapeutics. In recent years, the threat of viruses such as Ebola being utilized for bioterrorism, however, has led to more effort being put into finding effective vaccines and treatments.

One of the single most significant advances to come of the multiple sub-Saharan African Ebola outbreaks of the 2010s was the development of a vaccine known as rVSV-ZEBOV during the 2014 West African Ebola outbreak, which later became the first Ebola vaccine to be approved in the United States. The vaccine was found to be 90 to 100 percent effective against the Ebola virus disease just days after immunization, making it useful in the initial stages of an outbreak. It was used aggressively as part of a “ring vaccination” strategy during the 2018 Kivu Ebola outbreak, but its rollout was slowed by misinformation, distrust, community resistance, and armed conflicts in the region.

For Further Information:

“Ebola Haemorrhagic Fever.” World Health Organization, Aug. 2012.

“Hemorrhagic Fevers.” MedlinePlus, 20 May 2013. “Haemorrhagic Fevers, Viral.” World Health Organization, Jan. 2013.

Hewlitt, Barry S., and Bonnie L. Hewitt. Ebola, Culture, and Politics: The Anthropology of an Emerging Disease. Thomson Higher Education, 2008.

Shors, Teri. Understanding Viruses. 2nd ed., Jones and Bartlett, 2013.

Strauss, James H., and Ellen G. Strauss. Viruses and Human Disease. 2nd ed., Academic Press, 2008.

“Viral Hemorrhagic Fevers.” Centers for Disease Control and Prevention, 22 Nov. 2011.

Citation Types

Type

Format

MLA 9th

Wang., Dennis. "Viral Hemorrhagic Fevers." Magill’s Medical Guide, 9th Edition, edited by Anubhav Agarwal,, Salem Press, 2022. Salem Online, online.salempress.com/articleDetails.do?articleName=MMG2022_1445.

APA 7th

Wang., D. (2022). Viral hemorrhagic fevers. In A. Agarwal, (Ed.), Magill’s Medical Guide, 9th Edition. Salem Press. online.salempress.com.

CMOS 17th

Wang., Dennis. "Viral Hemorrhagic Fevers." Edited by Anubhav Agarwal,. Magill’s Medical Guide, 9th Edition. Hackensack: Salem Press, 2022. Accessed December 14, 2025. online.salempress.com.

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