syndrome (AIDS) This virus kills T-cells. A T-cell is a white blood cell
that fights infection and kills spontaneously arising tumors. HIV causes
Kaposi’s sarcoma, which is a rare form of cancer, and Pneumocystic
carinii,which is an opportunistic infection and causes pneumonia in
AIDS patients.- Human T-cell leukemia virus 1 and 2. Human T-cell leukemia virus 1
and 2is the virus that causes acute T-cell lymphocytic leukemiaand
often contains genes that cause cancer (oncogenic). - Togaviruses. Togavirusesis a virus, such as Estera equine encephalitis,
that is mainly transmitted through blood-sucking insects (arbovirus),such
as mosquitoes. It causes severe encephalitis. Another is the: - Rubella virus. The rubella viruscauses German measles,which can be
very dangerous if contracted during the first 10 weeks of pregnancy.
The rubella vaccineis used to weaken the disease producing ability of
the rubella virus. - Orthomytoviruses. Orthomytoviruses,such as influenza viruses A, B, and
C,cause localized infection of the respiratory tract, which is usually not
serious unless the infected person is elderly or the person is infected with
secondary bacterial pneumonia. Influenza viruses A and B can cause
Guillain-Barré Syndrome,which is an inflammation of the nerves that are
outside the brain and spinal cord (peripheral nerves); it appears 3 to 5
weeks after a person contracts the flu or after the person receives a flu vac-
cine. Influenza virus B causes Reyes syndrome,which is lethal to the liver
and the brain and causes a brain disease (encephalopathy) following a mild
flu, chickenpox, or the administration of aspirin. - Paramyxovirus. Paramyxovirus,such as the parainfluenza virus (Sendai
virus)causes croup in infants. Two other types of paramyxovirus are: - Mumps virus. The mumps viruscauses an enlargement of one or both
parotid glands and swelling and pain in the testes and ovaries. There is
a vaccine to protect humans from the mumps virus. - Measles virus. The measles virus,which is also known as rubeola,
causes measles. The measles virus causes a slow degeneration of the
nervous system of teenagers and young adults. If not treated, measles
can progress into encephalomyelitis or pneumonia. - Rhabdovirus. Rhabdovirus,such as the rabies virus (Lyssavirus),causes
rabies following an animal bite. In rare cases, a person can be infected by
inhaling the virus. Some animals such as bats pass the rabies virus through
to their feces.
CHAPTER 12 Viruses, Viroids, and Prions^191