<prompt> Infectivity of chicken pox last for -Till the last scab falls of6 days after onset of rash3 days after onset of rashTill the fever subsides  <response>: The incubation period of chickenpox is about 2 weeks. The patient is considered to be infectious during 2 days before and five days after the onset of lesions. REF:ANATHANARAYAN AND PANIKERS TEXTBOOK OF MICROBIOLOGY 8TH EDITION PAGE NO:471 