What is viral hemorrhagic fever (Ebola, Marburg, Lassa, New World Arenavirus, Crimean-Congo, Rift Valley Fever, Dengue Fever, Yellow Fever, Omsk Hemorrhagic Fever, or Kyasanur Forest Disease)?
Viral hemorrhagic fevers are rare diseases in the United States but more prevalent in Africa. THey are caused by four classes of viruses (Filoviruses, Arenaviruses, Bunyaviruses, and Flaviviruses). Humans are incidentally infected by a bite of an infected tick or mosquito, via aerosol generated from an infected rodent excretia, or by direct contact with infected animal carcasses. With the exception of Rift Valley fever and the diseases caused by Flaviviruses (Yellow fever, Omsk HF, and Kyasanur Forest Disease) which are not transmissible person-to-person, infected humans can spread the disease to close contacts by touching bodily fluids, which may result in community outbreaks and nosocomial infections. Person-to-person transmission by respiratory droplets through the air appears to be rare but cannot be ruled out. With intentional exposure, as in a bioterrorist release, breathing in airborne virus, or touching a substance with the virus and transferring it to the mucous membranes in the eyes or mouth are the most likely routes of entry into the body.
What are the symptoms of VHFs?
Clinical symptoms and signs of VHFs may include early onset of symptoms lasting for less than 1 week including fever, nausea and vomiting, joint and muscle pain, headache, extreme weakness, lack of strength, fatigue, sore throat, cough, chest and abdominal pain, and nonbloody diarrhea. Early signs also include slowing of pulse rate, rapid respiration, conjunctivitis, pharyngitis, weight loss, difficulty swallowing, shortness of breath, and for some VHFs, a rash. Later patients may show signs of bleeding of gums, vomiting blood, bloody stool, blood in urine, excessive bleeding at puncture sites, nose bleed, or blood in sputum.
Related PagesViral Hemorrhagic Fever Information for the Public Viral Hemorrhagic Fever Information for Public Health Officials