Types of Viral Hemorrhagic Fevers

Viruses that cause fever and bleeding are called viral hemorrhagic fevers. Some spread by contact. They may override the clotting system and patients bleed from the nose and gums or IV sites. Most are rare. They are nothing like a Zombie movie.

Most cases of most hemorrhagic viral fevers don't cause bleeding. It's rare, even with fatal Ebola, for there to be bleeding symptoms. They may be confused with malaria, which is often found nearby. This may delay isolation and put caregivers at risk. 

Dengue, infecting 100 to 400 million a year, can cause viral hemorrhagic fever. There are also other, less well-known causes.

yellow fever virus
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Lassa Fever

The Sierra Leone hospital that became an early Ebola hospital was a Lassa hospital. In some parts of Liberia and Sierra Leone, as many as 10%-16% of hospitalized patients have Lassa.

Lassa, an arenavirus found in West Africa, develops 1-3 weeks after exposure. Most people affected (80%) have mild symptoms: mild fever, fatigue, headache, while 20% develop bleeding (gums, nose), severe abdominal/chest/back pain, vomiting, facial swelling, possible confusion, or tremors. Shock can occur. Some hearing loss occurs in one-third of those with symptoms.

Of those hospitalized, approximately 15%-20% die (worse in pregnancy). Only 1% die overall. This fever's 300,000-500,000 cases cause approximately 5,000 deaths annually.

Lassa spreads when the multimammate rat's urine/droppings contaminate food or broken skin or are inhaled. Person-to-person transmission can occur, especially in resource-limited hospitals.

Ribavirin, an antiviral drug, is used. Diagnosis is based on PCR testing or ELISAs. There is no vaccine.

Last US case was in a returning traveler from West Africa in 2014.

There are other rare hemorrhagic fever (HF) arenaviruses in South America: Junin (Argentine HF), Machupo (Bolivian HF), Guanarito (Venezuelan HF), Sabia (Brazilian HF), Chapare virus (in Bolivia).


Marburg is related to another filovirus, Ebola. First recognized in 1967 among European lab workers infected by imported monkeys.

5-10 days after exposure, patients develop fever, headache, body aches, nausea, and vomiting. They can bleed on days 5-8, followed by shock, confusion.

Mortality rates differ depending on locale, maybe strain and resources; mortality was 21% in 1967 and up to 80-90% in Angola and DRC in 2000-5. Diagnosis is through PCR or ELISA. There is no specific treatment, yet. There is work on a vaccine.

The disease is found in Uganda, Zimbabwe, DRC, Kenya, Angola, and South Africa. Transmission is from African fruit bats—affecting miners (or tourists) in bat-filled caves through droppings (or even aerosolization). Transmission occurs from non-human primates and from patients if protection insufficient from patient body fluids or droplets. 

Marburg outbreaks are rare. Only 2 large outbreaks have occurred since 1970. Others clusters affected 1-15 people.

The last case seen in the US was in 2008 in a traveler returning from a bat-filled cave in Uganda.

Yellow Fever

Yellow Fever, spread primarily by Aedes mosquitoes, is a flavivirus like Dengue, Kyasanur, and causes hemorrhagic fevers. Yellow Fever occurs in parts of South America but mostly in Africa. 200,000 cases a year lead to 30,000 deaths. Most infected persons have little or no symptoms. Symptoms occur 3-6 days after exposure: fever, headache, fatigue, body aches, nausea, vomiting. Most improve, but some (about 15%) develop serious symptoms hours or a day later: bleeding, yellow skin, liver problems, high fever, shock. With severe disease, 20-50% die.

There are no specific treatments. Antibody testing can aid diagnosis.

One vaccine dose is thought to provide lifelong protection, and no booster doses are recommended. The vaccine is for—and only for—those traveling to Yellow Fever areas. Serious adverse events can occur; individuals should discuss vaccine contraindications with their doctor.

Prevention also includes using mosquito-repellant (DEET), covering up, avoiding Yellow Fever areas, and using bed nets (even if someone is already infected).

Hemorrhagic Fever With Renal Syndrome (HFRS)

Hemorrhagic fever with renal syndrome (HFRS) is caused by Bunyaviridae virusesHantaan, Seoul, Puumala, and Dobrava. There are about 200,000 cases worldwide each year, spread by aerosolized urine/droppings from specific rodents in Asia and Europe. The syndrome causes kidney problems, fevers, and rarely, bleeding. The American Southwest Hantavirus causes a different disease without bleeding.

The disease develops in 1-2 weeks (up to 8) after exposure with headaches, fever, blurry vision, abdominal/back pain. Some later develop kidney failure, shock, and vascular leakage. Mortality ranges from <1 to 15% depending on the strain. 

Other Hemorrhagic Fevers

Rift Valley fever and Crimean Congo are also hemorrhagic fevers but rarely do these infections lead to hemorrhaging. Dengue can also lead to hemorrhage, but rarely. Fulminant hepatitis, such as Hepatitis B, can affect coagulation and clotting. Severe icteric leptospirosis can also lead to hemorrhagic symptoms, but rarely and not very notably.

Viral Hemorrhagic Fevers Are Rare

If fever or any other symptoms of illness develop after visiting an affected area, seek medical attention immediately. It could be something more common like malaria, dengue, leptospirosis, but these need treatment and attention as well.

Do not take aspirin, Advil/ibuprofen, Aleve/naproxen (to avoid bleeding).

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