Viral Hemorrhagic Fever (cont.)
How are hemorrhagic fever viruses transmitted?
Viruses causing hemorrhagic fever are initially transmitted to humans when
the activities of infected reservoir hosts or vectors and humans overlap. The
viruses carried in rodent reservoirs are transmitted when humans have contact
with urine, fecal matter, saliva, or other body
excretions from infected rodents. The viruses associated with arthropod vectors
are spread most often when the vector mosquito or tick bites a human, or when a human crushes a tick.
However, some of these vectors may spread virus to animals, livestock, for
example. Humans then become infected when they care for or slaughter the
animals.
Some viruses that cause hemorrhagic fever can spread from one person to
another, once an initial person has become infected. Ebola, Marburg, Lassa and
Crimean-Congo hemorrhagic fever viruses are examples. This type of secondary transmission of the virus
can occur directly, through close contact with infected people or their body
fluids. It can also occur indirectly, through contact with objects contaminated
with infected body fluids. For example, contaminated syringes and needles have
played an important role in spreading infection in outbreaks of Ebola hemorrhagic fever and Lassa fever.
What are the symptoms of viral hemorrhagic fever illnesses?
Specific signs and symptoms vary by the type of VHF, but initial signs and
symptoms often include marked fever, fatigue, dizziness, muscle
aches, loss of strength, and exhaustion. Patients with severe cases of VHF often
show signs of bleeding under the skin, in internal organs, or from body orifices
like the mouth, eyes, or ears. However, although they may bleed from many sites
around the body, patients rarely die because of blood loss. Severely ill patient
cases may also show shock, nervous system malfunction, coma, delirium, and
seizures. Some types of VHF are associated with
renal (kidney) failure.
Next: How are patients with viral hemorrhagic fever treated? »
- Kidney Failure - Learn about kidney failure, in which the body has fluid retention, risen blood pressure, toxin build up and lack of red blood cells. Symptoms include fatigue, nausea, and apetite loss.
- Fever - Get the facts on fever treatment (in children and adults). Learn ways to bring down a high fever and know the signs of other serious types of major illness.
- Dengue Fever - Get the facts on dengue fever causes (virus transmitted by infected mosquito), symptoms, signs, treatment, statistics and information on dengue hemorrhagic fever (DHF).
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