CH. 17 Plagues on Order, Flu
~Bioterrorism attack- the deliberate release of viruses, bacteria, other germs (agents) used to
cause illness or death in people, animals, or plants. These agents are typically found in nature, but
it is possible that they could be changed to increase their ability to cause disease, make them
resistant to current medicines, or to increase their ability to be spread into the environment.
~Argentine hemorrhagic (Junin) feve r was developed because of change in agricultural practices.
home for little mouse (Calomys musculinis)
mouse carr ies Junin fever
human infec tions.
~Influenza (airborne virus)
-outbreak of 1918. Killed 500 million ppl. It killed much more ppl than black death or HIV.
-Outbreak was due to the crowding conditions of soldiers in Kansas. Mid- 1918, soldiers carr ies
disease to East Coast in the South then to Midwest and onward to Pacific states. In transit
across America, disease start appearing among civilian population.
-Symptoms: fever, chills, sore throat, lack of energy, muscular pain,headache, nasal congestion
(? ? ), lack of appetite.
Ro=10 // spread from person to person through coughing and sneezing.
-Virus does not hop on humans. Instead, wild birds maintain virus in their intestines (do not get
sick) carr ies the disease. Then, transmit to intermediate host – usually chicken, geese or ducks.
They tend to be dead-end hosts, but pigs live long enough to serve as virus mixing vessels.
Pigs’ cells have receptors for both birds and human virus.
-Genes: 2 surface proteins (both are critical)
hemagglutinin (H) and neuraminidae (N). H
acts as grappling hooks to host cell receptors. N allows the newly formed virus to dissolve.
They separate the virus from host cell and allow them to go between cells in the airway and to
move from cell to cell.
-No immune response because of the antigenic shift.
-Vaccine may also generate disease symptoms.
-Ppl infected with flu are at greater risk for pneumococcal pneumonia (bacterial disease),
which kills elderly ppl.
-Quarantining is not enough, treatment and immunization should also be used. Treatments
include: antiviral drugs that block N. If administered early enough, the virus dies because it
cannot be released.
-Another pandemic of flu is inevitable.