Hemorrhagic fever

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at October 21, 2016
StartDiseasesHemorrhagic fever

Hemorrhagic fever or viral hemorrhagic fever is a viral infection that is characterized by a high fever and internal bleeding. It is caused by five distinct families of RNA virus, and it can range from a mild to a life-threatening illness.

Contents

Definition & Facts

Hemorrhagic fever is a group of five different families of RNA viruses: Arenaviridae, Bunyaviridae, Filoviridae, Flaviviridae, and Paramyxoviridae. The viral infections have some differences, but many similarities. The virus is usually contracted in tropical climates, and it is sometimes spread around the world by travelers.

Transmission of hemorrhagic fever is through contact with infected insects, animals, or people. The infection affects the way blood clotting occurs. It also damages the body’s blood vessel walls, especially the tiny capillaries that network the arteries and veins. These leaks result in internal bleeding which can range from mild bruising to a life-threatening condition.

Symptoms & Complaints

Since there are at least five different viruses that can cause hemorrhagic fever, the symptoms may vary. In fact, some cases have very mild symptoms while others are much more severe. In general, some of the early symptoms of the virus may be: 

As the disease progresses, bleeding is likely to occur. Bleeding may be under the skin, in the organs, or it may come from the mouth, eyes, or ears.

Further complications from bleeding may be flushing of the face and chest, small red or purple spots on the skin, low blood pressure (hypotension), or swelling. In addition, a patient may also have headaches, vomiting, and diarrhea.

As the virus continues to progress, severe cases may have symptoms that include shock, nervous system malfunctions, or delirium. Organs such as the liver and kidneys may begin to fail, and a person may develop sepsis or lapse into a coma.

Causes

Hemorrhagic fever is caused by infectious viruses. More specifically, there are five known families of RNA virus that can cause this viral infection. Each of the different viruses live in a host, either an animal or an insect. Therefore each specific virus is most often seen only in the location where that host commonly lives. For example, certain viruses are only seen in West Africa while others are only in South America because that is where their infected host lives.

The viruses are transmitted to humans in a variety of ways. They may be transmitted via the bite of an insect, such as a mosquito or a tick. Other varieties of the viral infection can be transmitted by blood, semen, and even by breathing it in through the air. Some, but not all, of the viral infections can be transmitted from one infected human to another.

Living in or traveling to an area where the virus is known to be common is a risk for everyone. However, healthcare workers, those who slaughter infected animals, and those who work in rat-infested areas are at an even higher risk for developing hemorrhagic fever. Additionally, risky behaviors such as sharing needles for intravenous drug use and having unprotected sex put people in a high risk category as well.

Diagnosis & Tests

The diagnosis of hemorrhagic fever is complicated, especially in the beginning. In the first few days of the illness, many of the symptoms, such as fever, body aches, and extreme fatigue, are commonly experienced with many different infections including the flu.

Without knowing about possible exposures, a doctor would not likely even consider the viruses that cause hemorrhagic fever. Thus, when a person travels outside of the country, especially to developing nations, it is important for them to mention this to their doctor when symptoms appear after returning home. The doctor is then likely to discuss the travel itinerary as well as general medical history.

At that point, if a hemorrhagic fever virus is suspected, the patient may be isolated and have blood tests done in a special lab to confirm the diagnosis. It is important that the blood tests are done in a lab that can handle the possibility of a hemorrhagic fever virus since it could easily be spread without proper precautions. The blood tests of a person with one of the hemorrhagic fever viruses will have decreased white blood cell count, decreased platelet count, an increase in liver serum enzymes, and a decrease in blood clotting ability.

Treatment & Therapy

There is no known medication that can cure hemorrhagic fever. Doctors can only work to support the body and lessen the symptoms that occur. Some families of the virus respond to antiviral medication such as ribavirin. It is given intravenously, and it may help to lessen the intensity of some of the symptoms, or it may decrease the duration of the illness. Other medications are used on a trial basis and may have some potential to help against certain strains.

While waiting out the illness, it may be necessary to provide extra support to the patient. Patients may need extra fluids and electrolytes while they are ill. In addition, if the kidneys shut down or decrease in function, it may be helpful to perform dialysis to filter out the bodily wastes. Other body systems may also need added support and are evaluated on a case-by-case basis.

Prevention & Prophylaxis

Prevention of hemorrhagic fever is difficult. Prior to travel to developing countries, a doctor can decide if any immunizations or medications may help. Since there is only one readily available vaccine for these viral infections which prevents yellow fever, immunization is not likely to help. N

A person should try to avoid sources of the viruses including mosquitoes and ticks as much as possible. Insect repellent may be a good idea if avoidance is not possible. Once a human has contracted the disease, it is important to protect others by keeping the infected person in isolation and using strict contact precautions that may include HEPA-filtered respirators.