Viral Hemorrhagic Fevers By Christy Leaman

1. Discovering the World of Viral Hemorrhagic FeversBy Christy Leaman

2. Topic Overview • Definitions & Descriptions: • Infectious Diseases • Viral Hemorrhagic Fevers • Examples • Transmission • Hosts • Symptoms & Treatment • Implications for Humans Scary Examples Spread of VHFs Impact on Humans Quiz Yourself Learn More Subject Basics

3. Learning Objectives: • Describe the relationship between Infectious Diseases and Viral Hemorrhagic Fevers • Determine whether a human can be a host of a Viral Hemorrhagic Fever Scary Examples Spread of VHFs Impact on Humans Quiz Yourself Learn More Subject Basics

4. Infections Diseases: Diseases resulting from organisms like bacteria, viruses, fungi, or parasites Scary Examples Spread of VHFs Impact on Humans Quiz Yourself Learn More Subject Basics

5. Viral Hemorrhagic Fevers • A type of infectious disease that inhibits clotting of the blood • Involves extreme damage to multiple bodily systems • In particular, it inhibits the vascular system and the body’s ability to regulate itself Scary Examples Spread of VHFs Impact on Humans Quiz Yourself Learn More Subject Basics

6. Characteristics of VHFs • RNA viruses • Very few have a cure or successful drug treatment available • Survive primarily off a host • An organism that can carry the virus without being destroyed by it • Human outbreaks are unpredictable and sporadic Scary Examples Spread of VHFs Impact on Humans Quiz Yourself Learn More Subject Basics

7. Some examples of VHFs: • Dengue • Lassa Virus • Yellow Fever • Marburg • Ebola Do you want to see the most deadly of all VHFs? No, I’m scared! Yes, show me! Scary Examples Spread of VHFs Impact on Humans Quiz Yourself Learn More Subject Basics

8. Level 4 Hot Agents • Some VHFs are so deadly, they must be handled by a Special Pathogens Branch (SPB) • The SPB works with Biosafety level-4 pathogens or “hot agents” • Marburg and Ebola viruses have highest mortality rate Ebola outbreak 2007, Democratic Republic of the Congo Scary Examples Spread of VHFs Impact on Humans Quiz Yourself Learn More Subject Basics

9. Transmission • Host-Human: a host or contaminated object or substance comes into contact with a human • Host-Livestock-Human: virus is spread to humans during the slaughter or consumption of meat products • Human-Human: humans transfer the virus to other humans through contact with person or bodily fluids Scary Examples Spread of VHFs Impact on Humans Quiz Yourself Learn More Subject Basics

10. What are the hosts of VHFs? • VHFs arezoonotic: thevirus resides in an animal or arthropod • These are usually rodents, ticks, or mosquitoes • The hosts of viruses such as Ebola and Marburg remain unknown Scary Examples Spread of VHFs Impact on Humans Quiz Yourself Learn More Subject Basics

11. Where Do These Diseases Occur? • The virus and resulting disease generally stay in the host’s region • Increased travel brings a danger of mass disease spread • Marburg appeared in Germany • Ebola spread from Gabon to South Africa • Ebola Reston, a strain of Ebola which never infected humans, was found in monkeys in Reston, Virginia in 1990 Scary Examples Spread of VHFs Impact on Humans Quiz Yourself Learn More Subject Basics

12. Symptoms & Treatment • Marked fever • Dizziness • Weakness • Fatigue • Muscle aches • Exhaustion • Treatment: • In many cases, there is no effective drug treatment or vaccination available • Supportive therapy may be the only option Symptoms Include: • In severe cases: • Bleeding under the skin, in the internal organs, and from orifices such as the nose, eyes, and mouth Scary Examples Spread of VHFs Impact on Humans Quiz Yourself Learn More Subject Basics

13. Prevention and Control According to the CDC, prevention should involve: 1)Avoiding contact with potential hosts 2) Stop further transmission when a case occurs: -control rodent populations -use repellant, bed nets, and proper clothing -avoid contact with the sick Scary Examples Spread of VHFs Impact on Humans Quiz Yourself Learn More Subject Basics

14. How can scientists work to eliminate this threat? • Development of vaccine, • containment, and treatment • strategies • Development of diagnostic • tools • Understand VHF transmission and effects • Appreciate hosts and environmental ecology for prevention efforts Scary Examples Spread of VHFs Impact on Humans Quiz Yourself Learn More Subject Basics

15. Check your understanding! Correct! • A VHF is a type of Infectious Disease: TrueFalse • Are humans likely to be a host of a VHF? Yes No Sorry! A VHF IS a special type of Infectious Disease. Sorry! Humans become sick by these viruses; a host can carry the virus without being destroyed by it. Scary Examples Spread of VHFs Impact on Humans Quiz Yourself Learn More Subject Basics

16. Sources • U.S. Center for Disease Control, (2013). Viral hemorrhagic fevers. Retrieved from website: http://www.cdc.gov/ncidod/dvrd/spb/mnpages/dispages/Fact_Sheets/Viral_Hemorrhagic_Fevers_Fact_Sheet.pdf • World Health Organization, (2013). Viral hemorrhagic fevers. Retrieved from website: http://www.who.int/topics/haemorrhagic_fevers_viral/en/ • World Health Organization. (2007, September ). Ebola Haemorrhagic Fever in the Democratic Republic of the Congo [Web Video]. Retrieved from http://www.who.int/csr/disease/ebola/en/index.html • Mark. (Photographer). Infectious Disease News [Web Photo]. Retrieved from http://medicineworld.org/cancer/lead/2-2007/better-control-of-hemorrhagic-fever-viruses.html • Dengue Hemorrhagic Fever [Web Photo]. Retrieved from http://research.fuseink.com/pa5xgkmo7kz7rm/difference-between-malaria-and-degue-fever Scary Examples Spread of VHFs Impact on Humans Quiz Yourself Learn More Subject Basics

17. Disclaimer This project is for educational use only. Main Menu