discovery- understanding viruses Flashcards
why is it difficult to identify viruses?
they are the smallest organisms (only nanometers long; can only be seen with electroscopes)
there are many varieties of viruses
how did WW1 contribute to the flu pandemic of 1918?
if there had been no war, the strain would have remained isolated
when the armies fought, the virus was transmitted and then brought to their home countries; it then spread
who was immune to smallpox and why?
milkmaids- they caught cowpox (vaccinia); the disease was similar to smallpox and when the body was exposed to the more deadly disease (smallpox), the body recognized it and built antibodies
who was Edward Jenner?
he collected the cowpox disease and infected his own infant son; the son was not infected with smallpox when exposed to it
what are 2 ways to fight against viruses?
vaccines
the immune system (antibodies)
what is the difference between pandemic and epidemic?
pandemic- global
epidemic- more local
who was Jonas Salk?
developer of the polio vaccine (“the biggest news in medical history”)
used dead viruses rather than live ones- the body still became immune
what disease became extinct? why? when?
smallpox (disappeared 1978 but the virus still exists in labs)
due to the World Health Organization: scientists went around the world and vaccinated everyone- because the virus only lives in human hosts, once the last person was cured, the virus was gone
why is it so important for virologists to study life forms in tropical rain forests?
90% of the 14M species are unknown to us; these unknown species can harbour new viruses
what is the hanta virus?
caused haemorrhaging, kidney failure, death
originated from mouse urine during the Korean War
we are still vulnerable to it today, there is no treatment
why is there no treatment for some viruses?
it is very expensive and would only cure the few infected
what is Dysentery (Rota virus)?
caused severe diarrhea
poor hygiene- water source= where they defecate and urinate
what is HIV? where did it come from and how did it spread?
origin has not been pinpointed; likely a mutation of a monkey virus (theory: drinking money blood, eating monkey brain– when vehicular transportation became popular, it spread)
fast-mutating member of the RNA family
sexually transmitted
how can viruses help cure genetic diseases?
used in gene therapy to introduce new genes
change inborn defects in genetic code
reprogram (extract bad, add good) viruses to deliver missing DNA to cells
