Biology Questions and Answers
Viral Infections
- What are some human
diseases caused by virus and
what are their respective
modes of transmission?
The main viral disrespiratory secretioeases transmitted byns (sneezes, cough) (^)
and by salivasmallpox (vari drops are ola, already flu, mumps,considered (^)
eradicated), rubella, measles, SARS.
Main viral diseasblood or sexual contactes transmitted are AIDS, through
hepatitis B, hepatitis C, HPV, ebola
hemorrhagic ftransmitted by animal vectors areever. Main viral diseases
rabies, dengue fever, yellow fever.
Some viral disfecal-oral route, inclueases transmitted byding contaminate (^) d
food, are hepatitis A, poliomyelitis
(disease almost eraparts of the world).dicated in many
- What is the virus that
causes flu? Why doesn't the
body produce permanent
immunity against that virus?
How does the vaccine against
flu work?
Flu is a disease caused by the influenza
virus, a to the high mutation rathighly mutant DNA e of the virus,virus. Due (^)
that forms many different strains, flu
alwaysaffected populatio presents epidemic features inns and people may
have several flu episodes during life
(the immune response made from
previous infections is not efficient in
future infections).
The vaccine against flu is a vaccine
made of attenuated virus odifferent strains. Each year f threethe WHO (^)
(World Health Organization) researches
and determines wthat should compose hich arthe vaccine. This ise the strains (^)
a strategy to face the high mutation
rate of the virus.
- Why is rubella during
gestation a threat to the
fetus?
If occurring dangerous disease during gestationbecause the virus rubella is a
crosses the placenta and contaminates
the fetus. Tcongenital rubella, a teratohe fetus then developsgenic (cause (^)
of malformations) disease.
Congenital rvaccination. Dubella may be prevented byoctor must always be
consulted before vaccination.
- What are the main available
vaccines against
poliomyelitis?
The vaccinesare the Sabin used against poliomyelitisvaccine and the Salk
vaccine. The Sabin vaccine contains
attenuated virus anoral drops. The Salk vaccine d is taken is made ofthrough (^)
dead virus and is administered by
injection.
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