What You Need to Know About Viral Hemorrhagic Fevers (VHFs)
Read on to learn more about the causes, symptoms, treatments, and outlook for people with viral hemorrhagic fevers.
VHFs are a class of diseases that causes damage to multiple organ systems and often cause bleeding.
Several families of viruses cause these diseases. Few treatment options exist beyond supportive care, although newer antiviral medications may help in some cases. The resulting illnesses may be serious or even lethal.
Insects or rodents transmit most VHFs, but some can spread via person-to-person contact. Rapid isolation of people with VHFs and careful infection control practices are essential.
According to the Centers for Disease Control and Prevention (CDC), VHFs are increasing in prevalence, and outbreaks are difficult to predict. Factors like global travel and climate change contribute to the spread.
Four families of viruses cause VHFs.
Arenaviruses transmit mainly from rodents. The virus lives in rodent urine or feces. When these substances are stirred up, virus particles disperse through the air, where they can be inhaled.
Certain arenaviruses — like the Chapare, Lassa, Machupo, and Lujo viruses — can spread directly from human to human.
The arenaviruses include:
- Chapare virus
- Guanarito virus
- Junin virus
- Lassa virus
- Lujo virus
- lymphocytic choriomeningitis virus
- Machupo virus
- Sabia virus
Insects, ticks, and rodents usually spread bunyaviruses. They include:
- Crimean-Congo hemorrhagic virus
- Dobrava-Belgrade virus
- Puumala virus
- Rift Valley fever virus
- Saaremaa virus
- Seoul virus
- Sin Nombre virus
- severe fever and thrombocytopenia syndrome virus
- Tula virus
- phleboviruses, which are the only bunyaviruses that can spread from person to person
Filoviruses exist in animals. Bats are the reservoir hosts of the Marburg virus and possibly the ebolavirus. Once humans become infected, they can transmit the virus to other humans via body fluids. This places healthcare workers at increased risk.
There are five general types of filoviruses:
- Marburg virus
Flaviviruses are viruses found in arthropods like ticks and mosquitoes. These viruses are responsible for significant morbidity and mortality globally.
- dengue virus
- Kyasanur forest disease virus
- Omsk hemorrhagic fever virus
- yellow fever virus
- Japanese encephalitis
- West Nile virus
- Zika virus
- Alkhurma virus
- Usutu virus
- tick-borne encephalitis virus
- Powassan virus
People with VHFs often present with symptoms like:
- pain behind the eyes
- red eyes
- joint pain
- abdominal pain
- nausea or vomiting
- bleeding gums
- small red spots on the skin called petechiae
Patients with these symptoms who have traveled to areas where VHFs are prevalent should tell their physicians.
Your doctor will take a detailed history of your symptoms and assess your risk factors, including recent travel and recent contact with bats, rodents, or livestock. They will ask if you have been in contact with a sick person who has traveled to an area where VHFs are prevalent.
They will order isolation or infection control precautions and tests if they believe you may have a VHF disease. These tests may include:
- blood tests to check for clotting problems, viral RNA, other infections, and organ dysfunction
- chest X-ray to check for pulmonary or heart issues
- urine tests to check for blood in the urine and infections
The treatments for VHFs are largely supportive. For many of these illnesses, there is no specific medication available.
Supportive care includes managing fluid balances and maintaining blood pressure, medications for pain and nausea, supplemental oxygen, and possibly transfusions.
Two monoclonal antibody treatments have been approved by the Food and Drug Administration for disease caused by the Zaire ebolavirus strain. Inmazeb and Ebanga work by preventing viruses from entering a person’s cells.
The viruses that cause viral hemorrhagic fevers are dangerous because they have high morbidity and mortality rates. They can also be passed from person to person.
Mortality rates can reach as high as 80–90% in developing nations.
Recovery depends on the type of virus, the affected person’s immune response, and the level of supportive care available.
The most serious complication of VHFs is multisystem organ failure that leads to death.
According to the CDC, survivors of Ebola are at risk for long-term complications that include:
- chronic pain
- ringing in the ears
- memory loss
- sexual and reproductive problems
- psychological problems such as depression, anxiety, and post-traumatic stress disorder
Some factors that may raise your risk of getting a viral hemorrhagic fever include:
- recent travel to areas where outbreaks are occurring
- contact with people who have VHF, especially body fluids
- contact with animals that may be reservoirs for the viruses, including bushmeat
- residence in an area with lots of rodents or rodent droppings
- weakened immune system
Strict isolation precautions may prevent the spread of VHFs.
The World Health Organization (WHO) recommends that healthcare workers and caregivers use personal protective equipment that has the following characteristics:
- easy to put on and take off
- protects mucous membranes
- allows for unobstructed vision
- allows for communication
- can be disinfected repeatedly
- few junctions where exposure to body fluids might occur
- offers continuous protection while in use
Where possible, avoid contact with animals known to carry VHFs. Wash your hands frequently or use an alcohol-based hand sanitizer.
Avoid contact with and eating wild animals when traveling in areas where these viruses are endemic. Animals include monkeys, bats, and assorted other animals. Using mosquito and tick preventive sprays or solutions can also be beneficial.
Contact your physician if you have been in a region affected by VHFs and have symptoms. Avoid traveling to the physician’s office to prevent the spread of a VHF in the office.
There are vaccines available for Dengue fever and the Zaire ebolavirus strain. The Dengue fever vaccine is recommended only for people with a history of Dengue fever.
Viral hemorrhagic fevers are dangerous diseases that often have high complications and mortality rates.
Most VHFs are transmitted by animal vectors like mosquitoes, rodents, and ticks. Some are transmitted from person to person.
If you have traveled to an area known to have VHFs and have developed symptoms, or if you have other risk factors, tell your doctor right away. Supportive treatment and medications may help you recover from a VHF.
Strict isolation and infection control procedures may help prevent an outbreak from happening or worsening.