Final answer:
The thumb is the part of the hand most frequently missed during handwashing, and handwashing for at least 20 seconds with special attention to the thumb and other common missed areas is vital for preventing the spread of pathogens.
Step-by-step explanation:
The part of the hand most frequently missed during handwashing is the thumb. When washing hands, it's important to follow the recommended steps by health organizations to prevent the spread of pathogens.
These steps include thoroughly cleaning under the fingernails, between the fingers, the back of the hands, and especially the thumbs. Using liquid soap and scrubbing your hands for at least 20 seconds ensures that these often-neglected areas are cleaned efficiently.