Related Terms

  • Arenavirus, Argentine hemorrhagic, Bolivian hemorrhagic fever, Brazilian hemorrhagic fever, bunyavirus, filovirus, flavivirus, GTOV, guanarito virus, junin virus, JUNV, lassa virus, LASV, LMCV, lymphocytic choriomeningitis virus, machupo virus, MACV, mosquitoes, rats, sabia virus, SABV, ticks, Venezuelan hemorrhagic fever, VHF.

Background

  • Viral hemorrhagic fever (VHF) is a severe, often fatal, illness caused by four distinct families of viruses: arenaviruses, filoviruses, bunyaviruses, and flaviviruses. These viruses are all RNA viruses; are dependent upon a rodent, tick, or mosquito host for survival; have no drug treatment or cure, with few exceptions; and are restricted geographically to the areas where the host lives. The viruses that cause VHF are found all over the world but each virus is associated with one or more host species. Some VHF infections are rare while others affect millions of people each year.
  • VHF is spread to humans by contact with urine, saliva, or feces from infected rodents or a bite from an insect, such as a mosquito or tick. Each virus is usually associated with a specific insect or rodent host or closely related species. These animals maintain the virus and are not known to exhibit any symptoms of viral illness.
  • Some VHF organisms can enter the body by inhaled airborne particles or by direct contact with broken or chafed skin. Some arenaviruses, such as Machupo and Lassa viruses, can be spread by person-to-person contact. For example, hospital workers caring for infected individuals can acquire the infection.
  • Most VHF organisms are totally dependent on their host organism for replication and survival. The cotton rat, multimammate rat, house mouse, deer mouse, and other field rodents are examples of rodent hosts. The hosts of some VHF organisms, such as Marburg and Ebola, are currently unknown.

Risk Factors

  • Viral hemorrhagic fever (VHF) is spread to humans by contact with urine, saliva, or feces from infected rodents or a bite from an insect, such as a mosquito or tick. Some VHF organisms can enter the body by inhaled airborne particles or by direct contact with broken or chafed skin. Each virus is usually associated with a specific insect or rodent host or closely related species. These animals maintain the virus and are not known to exhibit any symptoms of viral illness. Contact with these substances and hosts therefore places individuals at higher risk of contracting VHF.
  • Travel to regions in which VHF is endemic also places individuals at higher risk. Risk may increase depending on types of activities, length of stay, and rate of transmission of a specific disease.
  • Hospital workers treating patients with VHF and laboratory researchers working with the viruses that cause VHF are also at higher risk.

Causes

  • Viral hemorrhagic fever (VHF) is spread to humans by contact with urine, saliva, or feces from infected rodents or a bite from an insect, such as a mosquito or tick. Each virus is usually associated with a specific insect or rodent host or closely related species. These animals maintain the virus and are not known to exhibit any symptoms of viral illness.
  • Some VHF organisms can enter the body by inhaled airborne particles or by direct contact with broken or chafed skin. Some arenaviruses, such as Machupo and Lassa viruses, can be spread by person-to-person contact. For example, hospital workers caring for infected individuals can acquire the infection.

Signs and Symptoms

  • All viral hemorrhagic fevers (VHF) begin gradually with flu-like symptoms that include fever, muscular aches, and cough. If the disease progresses, abdominal pain, vomiting, and diarrhea occur. The next stage involves sore throat, muscle pain, headache, chest pain, nausea and vomiting, facial swelling, conjunctivitis, or inflammation and swelling of the eyelids and portions of the eyeballs, and bleeding from the gums, intestinal tract, and other internal organs. If the disease progresses, individuals may develop temporary or permanent hearing loss, bleeding from the mouth and nose, blood in the urine, fluid in the lungs (pulmonary edema), and brain inflammation (encephalitis). In late stages, shock, seizures, coma, and death can occur.

Diagnosis

  • In many instances, humans infected with viral hemorrhagic fever (VHF) remain healthy and show no symptoms. In about 20% of cases, individuals develop severe disease that affects multiple systems of the body, including the liver, spleen, and kidneys. Hemorrhage and tissue damage may occur in these organs. This severe form of the disease has fatality rates ranging from 15% to 100%.
  • In the early stages of viral hemorrhagic fever (VHF), diagnosis is difficult because the symptoms, such as fever, muscular aches, and cough, resemble those of many other viral infections. A definite diagnosis can be made only in highly specialized laboratories. The arenavirus is composed of ribonucleic acid (RNA), which is a long chain of genetic material. The arenavirus RNA can be detected in patient specimens with a nested reverse transcriptase polymerase chain reaction (RT-PCR) assay, a laboratory procedure that is currently the most sensitive technique for detecting a specific type of RNA. In addition to identifying the RNA, this technique can determine the amount present in a sample.

Complications

  • One type of arenavirus, the lymphocytic choriomeningitis virus (LMCV), causes lymphocytic choriomeningitis (LCM). LCM infections have been reported in Europe, the Americas, Japan, and Australia. Bunyavirus, filovirus, and flavivirus infections all begin as arenavirus infections and can progress to internal bleeding.
  • Hantavirus pulmonary syndrome (PS) is a deadly disease that can cause dangerously low blood pressure (hypotension) and respiratory failure.
  • The Ebola virus is extremely deadly, having a mortality rate of 20% to 90%.
  • Flaviviruses are a family of viruses transmitted by mosquitoes and ticks. These viruses cause yellow fever, Kyasanur forest disease, Omsk hemorrhagic fever, and dengue fever. Dengue fever is one of the most common and widespread types of VHF. Fifty to 100 million cases occur worldwide each year.

Treatment

  • In the past several years, much progress has been made in understanding the molecular biology of viral hemorrhagic fever (VHF) viruses and how they cause disease. However, drugs or vaccines are currently unavailable for the treatment of most VHFs.
  • The antiviral drug ribavirin is effective for Lassa fever, which is caused by an arenavirus, if given early in the course of the disease. However, use of ribavirin is associated with birth defects. Therefore, women of childbearing age who are prescribed ribavirin should be advised to use birth control. Other antiviral drugs are under investigation for the treatment of VHF.
  • Treatment is generally aimed at the reduction of symptoms and prevention of management of complications. Treatment should ensure adequate fluids and electrolytes, maintenance of proper breathing, monitoring of kidney and bladder function, and treatment of any secondary infections.

Integrative Therapies

Note
: Currently, there is a lack of scientific evidence for the use of integrative therapies in the treatment or prevention of viral hemorrhagic fever. The therapies below have been studied for use in viral infections in general, should be used only under the supervision of a qualified healthcare provider, and should not be used in replacement of other proven therapies.

C

Unclear or conflicting scientific evidence

  • Alizarin
    : Limited available evidence suggests that alizarin may improve various herpes infections. Additional study is needed before a firm recommendation can be made. Avoid if allergic or hypersensitive to alizarin or any plants in the Rubiaceae family. Alizarin may be toxic and should not be handled for long periods of time, rubbed in the eyes, or eaten. Avoid if pregnant or breastfeeding.

  • Astragalus
    : Astragalus products are derived from the roots of Astragalus membranaceus or related species, which are native to China. In traditional Chinese medicine, astragalus is commonly found in mixtures with other herbs, and is used in the treatment of numerous ailments, including heart, liver, and kidney diseases, as well as cancer, viral infections, and immune system disorders. Anti-viral activity has been reported with the use of astragalus in laboratory and animal studies. Limited human research has examined the use of astragalus for viral infections in the lung, heart (pericarditis, myocarditis, endocarditis), liver (hepatitis B and C), cervix (papilloma virus), and in HIV disease. Studies have included combinations of astragalus with the drug interferon, or as a part of herbal mixtures. However, most studies have been small and poorly designed. Due to a lack of well-designed research, firm conclusions cannot be drawn.

  • Avoid if allergic to astragalus, peas, or any related plants, or with a history of Quillaja bark-induced asthma. Avoid with aspirin or aspirin products or herbs or supplements with similar effects. Avoid with inflammation (swelling) or fever, stroke, transplant or autoimmune diseases (like HIV/AIDS). Stop use two weeks before surgery/dental/diagnostic procedures with a risk of bleeding and avoid use immediately after these procedures. Use cautiously with bleeding disorders, diabetes, high blood pressure, lipid disorders or kidney disorders. Use cautiously with blood-thinners, blood sugar drugs, or diuretics or herbs and supplements with similar effects. Avoid if pregnant or breastfeeding.
  • Blessed thistle
    : Blessed thistle leaves, stems, and flowers have traditionally been used in “bitter” tonic drinks and in other preparations taken by mouth to enhance appetite and digestion. Evidence of activity of blessed thistle against herpes viruses, influenza, or poliovirus is currently lacking in available preliminary research. Effects of blessed thistle (or chemicals in blessed thistle called lignans) against HIV are not clear. Human research of blessed thistle as a treatment for viral infections is lacking.

  • Avoid if allergic to blessed thistle, mugwort, bitter weed, blanket flower, chrysanthemum, coltsfoot, daisy, dandelion, dwarf sunflower, goldenrod, marigold, prairie sage, ragweed, Echinacea or any plants of the Asteraceae or Compositae families. Use cautiously with peptic ulcer disease. Avoid with a history of bleeding diseases or gastroesophageal reflux disease (GERD), or if taking drugs for blood thinning, stroke, stomach diseases, or to control stomach acid. Avoid if pregnant or breastfeeding. Stop use two weeks before surgery/dental/diagnostic procedures with bleeding risk and do not use immediately after these procedures.
  • Cranberry
    : Cranberry is popular as a food, and is often consumed as relish, sauce, jam, juice, or dried berries. Limited laboratory research has examined the antiviral activity of cranberry. Reliable human studies supporting the use of cranberry in this area are currently lacking. Avoid if allergic to cranberries, blueberries, or other plants of the Vaccinium genus. Sweetened cranberry juice can affect blood sugar levels. Use cautiously with history of kidney stones. Avoid more than the amount usually found in foods if pregnant or breastfeeding.

  • Focusing
    : Early research showed that increased experiential involvement (an indication of focusing taking place) did not have an effect on antibody titers to Epstein-Barr virus. More studies in the area of immune function and antibody production are required before a recommendation can be made in this area.

  • Green tea
    : Preliminary research suggests that green tea decreases viral load in carriers of the HTLV-1 virus. Additional well-designed controlled research is needed before a recommendation can be made for or against use of green tea in the treatment of HTLV-1 carriers. Avoid if allergic or hypersensitive to caffeine or tannin. Use cautiously with diabetes or liver disease.

  • Sorrel
    : Historically, sorrel has been used as a salad green, spring tonic, diarrhea remedy, weak diuretic, and soothing agent for irritated nasal passages. Sorrel has been used with other herbs to treat bronchitis and sinus conditions in Germany since the 1930s. There is currently a lack of well-conducted published studies that demonstrate antiviral or antibacterial activity of sorrel. In available laboratory study, sorrel did not demonstrate activity against herpes simplex virus-1, herpes simplex virus-2, HIV, B. subtilis, E. coli, Proteus morganii, Pseudomonas aeruginosa, P. vulgaris, Serratia marcescens, or Staphylococcus aureus.

  • Avoid with a known allergy to sorrel. Avoid large doses of sorrel because there have been reports of toxicity and death, possibly due to oxalates found in sorrel. Tinctures contain high levels of alcohol and should be avoided when driving or operating heavy machinery. High alcohol sorrel formulations may also cause nausea or vomiting when taken with the prescription drugs metronidazole (Flagyl®) or disulfiram (Antabuse®). Avoid if pregnant or breastfeeding.
  • Turmeric
    : The rhizome (root) of turmeric (Curcuma longa Linn.) has long been used in traditional Asian medicine to treat gastrointestinal upset, arthritic pain, and “low energy.” Evidence suggests that turmeric may help treat viral infections. However, there is currently not enough human evidence in this area. Well-designed trials are needed to determine if these claims are true.

  • Avoid if allergic or hypersensitive to turmeric, curcumin, yellow food colorings, or plants belonging to the Zingiberaceae (ginger) family. Use cautiously with a history of bleeding disorders, immune system deficiencies, liver disease, diabetes, hypoglycemia, or gallstones. Use cautiously with blood-thinners, such as warfarin (like Coumadin®), and blood sugar-altering medications. Avoid in medicinal amounts if pregnant or breastfeeding. Turmeric should be stopped prior to scheduled surgery.
  • Vitamin A
    : The role of vitamin A in the prevention, transmission, or treatment of HIV is controversial and not well established. A clear conclusion cannot be formed based on the available scientific research. Vitamin A supplementation has also been suggested to help prevent NoV infection in children and reduce the symptoms associated with NoV infections. Additional research is needed in this area.

Prevention

  • Prevention of viral hemorrhagic fever (VHF) includes avoiding mosquito bites and promoting a clean community environment that discourages rodents from entering homes. Effective measures include insecticide-soaked mosquito nets, insect repellants, full-length clothing, staying indoors between dawn and dusk, storing food in rodent-proof containers, and disposing garbage away from the home.
  • Vaccines and treatment for the vast majority of VHF infections are at present extremely limited. Current treatment primarily consists of supportive measures, such as provision of fluids and electrolytes and maintenance of normal blood pressure.

Author Information

  • This information has been edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

References

Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.

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