and described by the formula: where A is the amplitude of oscillation, f is the frequency, t is the elapsed time, and is the phase of the oscillation. The phase determines or is determined by the initial displacement at time t = 0. A motion with frequency f has period. Two potential ambiguities can be noted:
Incubation Period Shingles is not transmitted from exposure to another infected person so there is no applicable incubation period. Anyone who has recovered from varicella may develop shingles. Mode of Transmission Transmission of the virus occurs through direct contact with the rash or fluid from the lesions.
It is transmitted mainly by respiratory droplets that contain infectious particles; direct contact with a lesion and contaminated equipment also can spread the virus. Reactivation of the virus in adults causes shingles. Synonym: chickenpox See: illustration; herpes zoster; varicella-zoster immune globulin Symptoms After an incubation period of 2 to 3 weeks (usually 13 to 17 days), patients develop fever, malaise, anorexia, and lymphadenopathy, followed by the appearance of an extremely pruritic (itchy) rash that starts flat and, over time, becomes a small blister on a red base, and then eventually forms crusted scabs.