With decreasing incidence of varicella overall and increasing varicella vaccination coverage, more than half of varicella cases reported during the mature phase of the vaccination program are breakthrough varicella cases. As with other viral diseases, re-exposure to natural (wild) varicella may lead to reinfection that boosts antibody titers without causing clinical illness or detectable viremia.īreakthrough varicella is defined as varicella due to infection with wild-type VZV occurring more than 42 days after varicella vaccination breakthrough infection can occur after 1 or 2 doses of vaccine. In otherwise healthy persons, a second occurrence of varicella is uncommon it is more common in immunocompromised persons. Recovery from primary varicella infection usually results in lifetime immunity. Persons infected with human immunodeficiency virus (HIV) are also at risk for severe, prolonged illness. Immunocompromised children may develop a severe progressive form of varicella characterized by high fever, extensive vesicular eruption, and high complication rates. Adults may have more severe disease and have a higher incidence of complications. The clinical course in healthy children is generally mild, fever (up to 102☏) and other systemic symptoms (e.g., malaise, headache) usually resolve within 2 to 4 days after onset of the rash. Healthy children usually have 250 to 500 lesions in 2 to 4 successive crops. For example, macular lesions may be observed in the same area of skin as mature vesicles. Successive crops appear over several days, with lesions present in all stages of development at the same time. Vesicles may rupture or become purulent before they dry and crust. The vesicles are superficial and delicate and contain clear fluid on an erythematous base. Lesions are usually 1 to 4 mm in diameter. Lesions also can occur on mucous membranes of the oropharynx, respiratory tract, vagina, conjunctiva, and the cornea. The rash usually appears first on the scalp, face or trunk, and then spreads to the extremities the highest concentration of lesions is on the trunk. In individuals who have not received varicella vaccine, the rash is generalized and pruritic and progresses rapidly (within 24 hours) from macules to papules to vesicular lesions before crusting. Recovery usually results in lifetime immunity.Clinical course in healthy children is mild adults may have more severe disease.In unvaccinated individuals, generalized and pruritic rash progresses rapidly.Rash often first sign of disease in children adults may have 1 to 2 days of fever and malaise before rash.In 2005, a combination measles, mumps, rubella, and varicella (MMRV) vaccine was licensed in the United States for persons age 12 months through 12 years. Varicella vaccine was licensed for general use in Japan and Korea in 1988, and in the United States in 1995 for persons age 12 months or older. The vaccine virus was developed from virus isolated by Michiaki Takahashi from vesicular fluid from an otherwise healthy child with varicella disease. A live, attenuated varicella vaccine was developed in Japan in the 1970s. In 1954, Thomas Weller used cell culture to isolate VZV from vesicular fluid of patients with varicella or zoster. In 1875, Rudolf Steiner demonstrated that chickenpox was caused by an infectious agent by inoculating volunteers with the vesicular fluid from a patient with acute varicella. Primary varicella infection (chickenpox) was not reliably distinguished from smallpox until the end of the 19th century. Varicella is an acute infectious disease caused by varicella-zoster virus (VZV). Varicella and MMRV vaccines licensed for use in the U.S.Live, attenuated varicella vaccine developed in 1970s.Distinguished from smallpox at the end of the 19th century.Acute infectious disease caused by varicella-zoster virus (VZV).
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