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.
Risk Factors for Shingles (Herpes Zoster) About 500,000 cases of shingles occur each year in the U.S. Anyone who has had chickenpox has risk for shingles later in life, which means that 90% of adults in the U.S. are at risk for shingles.