How often should people wash their hands to maintain good personal hygiene? once per day at least twice per week whenever their hands are visibly dirty whenever they touch unclean surfaces

What link in the chain of transmission is described in the paragraph? sarah has been eating and sleeping poorly. she was just diagnosed with pneumonia. tests showed the illness was caused by streptococcus pneumoniae. in the chain of transmission, sarah is the (blank) , and streptococcus pneumonia is the (blank).