VHF (Viral Hemorrhagic Fever) diseases are often transmitted to humans through contact with infected animals or insects.
Here's a breakdown of how VHF diseases spread:
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Animal Reservoirs: Many VHF viruses reside in animal hosts, often rodents, insects (like mosquitoes or ticks), or other animals. These animals may carry the virus without showing any symptoms themselves.
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Transmission Routes:
- Direct Contact: Direct contact with infected animal reservoirs (e.g., rodents) through their urine, droppings, saliva, or nesting materials is a common route of infection.
- Arthropod Vectors: Mosquitoes and ticks can transmit VHF viruses through their bites. These infected arthropods act as vectors, carrying the virus from an infected animal to a human.
- Human-to-Human Transmission: Some VHF viruses can spread from person to person via direct contact with bodily fluids (blood, vomit, saliva, etc.) or contaminated objects (needles, medical equipment). Aerosol transmission (through respiratory droplets) is less common but possible with some VHF diseases.
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Specific Examples: While the exact modes of transmission vary with each VHF, some common scenarios include:
- Lassa Fever: Transmitted through contact with rodent urine or droppings.
- Ebola and Marburg: Spread through contact with bodily fluids of infected individuals or animals.
- Dengue and Yellow Fever: Transmitted through the bite of infected mosquitoes.
- Crimean-Congo Hemorrhagic Fever (CCHF): Transmitted by tick bites or contact with infected animal blood or tissues.
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Occupational Risk: Certain professions, such as healthcare workers, veterinarians, and laboratory personnel, have a higher risk of exposure to VHF viruses.
In summary, VHF diseases are typically transmitted through contact with infected animals or vectors, and in some cases, can spread from human to human through direct contact with bodily fluids.
