The Health Department is investigating an outbreak of varicella (chickenpox) in the Orthodox Jewish community of Williamsburg, Brooklyn.
To date, there have been 75 reports of persons with varicella who became ill during or after March 2016. The median age of patients is 3 years (range 0 to 10 years); 72% were not vaccinated against varicella, and 14% had not yet received the recommended number of doses.
Varicella is an illness characterized by a generalized, pruritic rash. It progresses from macules to papules to vesicular lesions and then crusts over. Lesions are usually most concentrated on the trunk.
Persons who were previously vaccinated may develop varicella, but symptoms of infection are often mild; fewer lesions may develop, lesions may not be vesicular, and fever may be absent. It is important to maintain a high index of suspicion for varicella in patients presenting with a compatible illness, regardless of vaccination history. Infants, adolescents, adults, pregnant women, and immunocompromised persons are at risk for more severe disease and complications. Complications include pneumonia, bacterial infection of the skin and soft tissues, meningitis, encephalitis, birth defects, and death.
Transmission and Infection Control
Varicella is highly contagious. People with varicella are contagious beginning 2 days before rash onset until all lesions have crusted and no new lesions have appeared for a 24 hour period. People who are not immune to varicella are at risk for getting sick from 10 to 21 days after exposure, and they may be contagious as early as 8 days after exposure. In healthcare settings, providers should institute contact, droplet and airborne precautions. All healthcare workers should have evidence of immunity to varicella (see below).
The Health Department has advised that children should be up to date with varicella-containing vaccine.
Two doses of the vaccine are up to 98% effective at preventing chickenpox. Varicella vaccine should be given to children at 12 months of age with a second dose at 4 years of age. Two doses of vaccine are recommended for older children and adults who do not have evidence of varicella immunity.
Adults who do not know if they had varicella and who do not have their immunization records should either be vaccinated or can have varicella IgG titers checked to confirm whether they are immune. Vaccination histories of children can be obtained through the Citywide Immunization Registry at www.nyc.gov/health/cir or by calling 347-396-2400.