chickenpox = 3days before rash , until last vesicle crusted
mump = 3days before , 1week after "salivary swelling "
pertussis = 3days before - 3week after start of symptoms (5days if on appropriate antibiotics)
measles = 4days before rash , 5 days after rash appear
hepatitis A = 1 week before , 2 week after jaundice start
rubella = 1week before , 1 week after rash onset
scarlet fever = 10-21 from onset of rash (1day if on penicillin)
