Microbiology 9th Edition by Laura Black, Jacquelyn Black

تمرين 15

All of the following are true about poliomyelitis EXCEPT:
(a) Most poliovirus infections are inapparent or mild and nonparalytic.
(b) Polio can be caused by three strains of picornaviruses.
(c) The Salk vaccine contains live, attenuated polioviruses while the Sabin vaccine contains formalin-inactivated polioviruses.
(d) Transmission is by the fecal-oral route and pharyngeal secretions.
(e) Poliomyelitis has afflicted man for thousands of years.