Reddy: Vector Borne and Zoonotic Infections/ Bioterrorism Flashcards
New Viral Diseases (since 1976):
- Ebola Fever
- Adult T Cell Leukemia (HTLV)
- AIDS
- Hepatitis C
- Hantavirus
- HHV8
- SARS
Re-Emerging Viruses (severe epidemics):
- Yellow Fever
- Dengue Fever
- Measles Virus
- West Nile Virus
- St.Louis Encephalitis Virus
- Monkeypox Virus
- Pandemic flu
Weapons of Bioterrorism:
Small pox virus
Factors Contributing to Emergence of Infectious Diseases:
Ecological/Environmental Changes: for example, weather anomalies and Hantvirus pulmonary syndrome
Behavior: for example, sexual behavior/IV drug use and AIDS
Human Demographics: for example, urbanization/increased population density and Dengue Fever
Technology and Industry: for example, blood tissue products for medical use and AIDS, HBV and HCV
Possible Causes of Emerging Diseases:
- Infected human host or reservoir
- Human-transported vertebrae host (legal or illegal)
- Storm-transported vertebrae host (bird)
- Intentional induction (terrorist event)
Last Case in US:
Two Reserves for Smallpox:
Last Case in US: 1949; eradicated from the world in 1977 (stop vaccinating for it in the US in 1972)
Two Reserves for Smallpox:
o CDC (Atlanta, US)
o Institute of Virus Preparations (Moscow, Russia)
Smallpox
Genus:
Structure:
Genome:
o Genus: Orthopoxvirus
o Structure: brick shaped, enveloped
o Genome: dsDNA; replicates in cytoplasm
Smallpox
Disease Symptoms:
o Fever and chills o Headache o Malaise o Sore throat o Cough o Backache o Painful skin lesions (centrifugal rash that scabs and scars)
Smallpox
Incubation Period:
Transmission:
Incubation Period: 10-14 days (for both variola major and minor)
Transmission: respiratory route (stable in environment); also direct contact
Smallpox
Types of Disease
Based on mortality:
Variola major (~30% mortality) Variola minor (~1% mortality)
Flat-type smallpox:
Flat-type smallpox: RARE; slow evolution of flat, soft, focal skin lesions (high mortality, especially in unvaccinated)
Hemorrhagic-type smallpox:
Hemorrhagic-type smallpox: RARE; extensive mucosal hemorrhage and intense toxemia (die before lesions appear)
Smallpox
Virus Genus Replication Incubation Distribution Growth of Eruptions Pustules Scab Formation Scab Separation Scaring
Variola Orthopoxvirus Cytoplasm 7-17 days Face, palms and soles Synchronous Firm and deep 10-14 days after rash onset 14-28 days after rash onset Yes
Chickenpox
Virus Genus Replication Incubation Distribution Growth of Eruptions Pustules Scab Formation Scab Separation Scaring
VZV Herpesvirus Nucleus 14-21 days Trunk Different Stages Soft and superficial 4-7 days after rash onset <14 days after rash onset No (normally)
Smallpox
Diagnostic Tests:
Skin Samples:
• Electron microscopy (EM)
• Immunoflurorescence
• PCR
Smallpox
Vaccination:
Post-Exposure Therapy:
Pre-Exposure Preventive Vaccine: uses a special needle (bifurcated)
• No longer part of vaccine regimen in the US (singe 1972)
• US government has enough smallpox vaccine to effectively respond to a smallpox outbreak
Post-Exposure Therapy:
• Supportive therapy
• Antibiotics for secondary infection
• Antivirals against it are under investigation currently
Monkeypox
Similar signs and symptoms to:
Originated:
People got sick after having contact with:
Transmission:
Similar signs and symptoms to smallpox: mortality rate was higher BEFORE the eradication of smallpox
Originated in West and Central Africa in the 1970s: first time reported in the US was in 2003
People got sick after having contact with prairie dogs infected with monkeypox