Ebola Virus a new terror agent: Dengue like illness with rabies like mortality

1. The filoviruses, Marburg and Ebola, are among the most virulent human pathogens.
2. Case fatality rates are 80 to 90 percent.
3. Ebola viruses are also classified as "hemorrhagic fever viruses" based on their clinical manifestations, which include coagulation defects, a capillary leak syndrome, and shock.
4. Other types of viral HF include Rift Valley fever, Crimean–Congo HF, Lassa fever, yellow fever, and dengue HF.
5. The filoviruses, Marburg and Ebola, are among the most virulent human pathogens, causing severe hemorrhagic fever that resembles fulminant septic shock.
6. Person–to–person transmission requires direct contact with blood or other virus-containing body fluids.
7. The reservoir host of the filoviruses is not known.
8. Various bat species may serve as a source of infection for both humans and wild primates.
9. Flavi viruses cause extensive tissue damage
10. They also induce a systemic inflammatory syndrome by causing the release of cytokines, chemokines, and other proinflammatory mediators from infected macrophages.
11. The incubation period is usually 5 to 7 days, but may exceed two weeks.
12. Patients usually have an abrupt onset of non–specific symptoms, such as fever, malaise, and myalgias.
13. As the illness progresses, patients develop worsening prostration, stupor, and hypotension.
14. Signs of impaired coagulation generally remain limited to conjunctival hemorrhages, easy bruising, and failure of venipuncture sites to clot.
15. Due to their virulence, stability as aerosols, and high infectivity, Marburg and Ebola viruses are classified as Category A bioterror agents.
16. The occurrence of even a single human infection outside of Africa is therefore a public health emergency requiring immediate investigation, since it could represent the leading edge of an impending outbreak.
17. Rapid diagnostic tests for Marburg and Ebola virus infection have been developed, based on the detection of viral antigens by enzyme–linked immunosorbent assay (ELISA) or specific RNA sequences by reverse–transcription polymerase chain reaction (RT–PCR) in blood or other body fluids. The diagnosis is confirmed through cell culture.
18. No specific therapy is available for patients who have developed Ebola or Marburg hemorrhagic fever; care is supportive.
19. Health care workers should employ isolation and barrier procedures recommended by the Centers for Disease Control and the World Health Organization when caring for patients with suspected or known filovirus infection.
20. Platelets count may fall and SGOT may be more than SGPT as seen in dengue fever.

Bioterrorism

The CDC has identified a number of pathogens that could be used in biological terrorism and have ranked them into various categories based on their overall potential to cause harm. High–priority agents include organisms that:

• Can be easily disseminated or transmitted person–to–person
• Cause high mortality
• Might cause public panic and social disruption
• Require special action for public health preparedness

1. The highest priority agents (Category A) include anthrax and smallpox. These agents are of particular concern because they can be grown easily in large quantities and are sturdy organisms, resistant to destruction. They are also particularly well suited to airborne dissemination, thereby infecting large numbers of people.
2. Second highest priority agents (Category B) include those that are moderately easy to spread, and generally cause less morbidity and mortality than Category A, but may require enhanced diagnostic capacity or surveillance techniques. Examples include agents of Q fever or brucellosis.
3. Category C agents include pathogens that could be engineered for mass dissemination either because of ready availability, or ease of production and transport. They are usually agents of significant potential morbidity and/or mortality. Examples include hantavirus or multidrug–resistant tuberculosis.

Because of their virulence, stability, and high infectivity as small–particle aerosols, Marburg and Ebola virus are classified as Category A bioterror agents by the Centers for Disease Control and Prevention (CDC) and the National Institute of Allergy and Infectious Diseases (NIAID).

The occurrence of even a single human infection outside of Africa is therefore a public health emergency requiring immediate investigation, since it could represent the leading edge of an impending outbreak. Marburg and Ebola hemorrhagic fever occur naturally only in central Africa.