Ongoing varicella outbreak affects 75 children in New York

The New York City Department of Health and Mental Hygiene recently issued an advisory to physicians concerning an ongoing investigation into 75 cases of varicella in the Williamsburg section of Brooklyn.

Perspective from

Health officials said the outbreak has been occurring among an Orthodox Jewish community since March and has affected 75 children aged younger than 10 years. According to the advisory, 72% of the patients were not vaccinated against chickenpox, and 14% had not completed the vaccine series. Officials noted that two doses of varicella vaccination are 98% effective at protecting against the disease.

“Please ensure that your patients and staff are up to date with varicella vaccine,” health officials wrote in the advisory. “Two doses of vaccine are recommended for older children and adults who do not have evidence of varicella immunity.”

The advisory was issued to all pediatricians, PCPs, infectious disease specialists, emergency medicine physicians, internal medicine specialists, family medicine specialists, obstetricians and gynecologists, laboratory medicine specialists and infection control staff within the city.

Physicians are advised to prioritize treatment for high-risk groups and to provide post-exposure prophylaxis within 3 days of initial exposure. Health officials do not recommend antiviral treatment to otherwise healthy children infected with varicella. Antiviral treatment should be considered for those at increased risk for moderate to severe varicella, according to the advisory.

Perspective

Walter A. Orenstein

Julie R. Garon

Chickenpox, the common childhood disease caused by the varicella-zoster virus is highly contagious yet vaccine preventable. The disease – consisting of fever, malaise, loss of appetite, headache and rash leading to blisters – is most infectious from 1-2 days before the rash appears until scabs have formed over all blisters (approximately 5-7 days from onset). The virus is spread through the air via coughing, sneezing and breathing in virus particles, which emerge from blisters. Among unvaccinated populations, up to 90% of those exposed will become infected; however, the recommended two-dose schedule for varicella vaccine is 98% effective at preventing chickenpox.

While chickenpox was once a considered a childhood rite of passage, complications can include pneumonia, bacterial superinfections, encephalitis and even death. Prior to licensure of the varicella vaccine, an estimated 4 million cases of chickenpox took place globally each year resulting in 10,600 hospitalizations and 100-150 deaths annually. Varicella can be particularly severe in immunocompromised persons who cannot receive the vaccine. Such persons can be protected indirectly if there are high enough immunity levels in the population to prevent transmission and exposure to the virus.

Orthodox Jewish communities in the U.S. have experienced outbreaks of vaccine-preventable diseases in the past, mostly recently with measles in 2013 and mumps in 2009-2010. The often low vaccination coverage in this population along with the likelihood of close, maintained contact of children in yeshivas or other social and cultural gatherings provides an optimal setting for the spread of highly infectious diseases such as chickenpox.

Through working to increase acceptance of vaccines among these communities and by improving coverage rates in vulnerable populations such as these, we can ensure all children are protected from this dangerous, yet highly preventable disease.

Walter A. Orenstein, MD
Infectious Diseases in Children Editorial Board member
Emory University School of Medicine

Julie R. Garon, MPH
Division of Infectious Diseases
Emory University School of Medicine

Disclosures: Orenstein and Garon report no relevant financial disclosures.