TERRE HAUTE —
Vigo County “is experiencing the largest known outbreak of chickenpox in the nation,” according to Dr. Joan Duwve, chief medical officer with the Indiana State Department of Health.
The Tribune-Star’s Sue Loughlin, who has been following the story for days, submitted a list of questions about the outbreak to Dumve, who emailed the following responses:
Question: From the perspective of the Indiana Department of Health, how serious is the chickenpox outbreak in Vigo County?
Answer: Chickenpox is a very contagious disease, and Vigo County is experiencing the largest known outbreak of chickenpox in the nation. Vigo County usually has less than 10 cases a year; however, since the end of September, Vigo County has reported 84 cases which would meet the definition of an unusual occurrence of disease. Prompt identification, investigation and control of chickenpox outbreaks are important. Even mild cases can be contagious.
(On Monday, the Vigo County Health Department erroneously reported that there have been more than 100 cases of chickenpox. The correct number as of Tuesday was 84, according to Joni Wise, health department administrator).
Q: Do any other counties in Indiana have an outbreak?
A: Neighboring Parke County also has an outbreak of varicella in a school. Parke County has reported eight cases to date.
Q: Any thoughts as to why Vigo County is having an outbreak, and not other counties? We’re hearing it’s a “breakthrough” chickenpox often affecting children who have already been immunized.
A: We wish we knew why Vigo County is having an outbreak. The original case was an unvaccinated person attending school and may have introduced the virus into the school, although chickenpox may also have been circulating in the community.
Chickenpox is readily transmitted in preschool and school settings. Two doses of chickenpox vaccine is 90 percent effective at preventing disease. So, although one out of every 10 children who [is] fully vaccinated may still be susceptible to disease. Vaccination will prevent disease in nine out of every 10 children exposed.
To prevent outbreaks, communities must maintain very high levels of immunization. A less severe form of chickenpox called breakthrough chickenpox may occur in anyone who has received one or two doses of varicella vaccine, even if appropriately administered. It presents atypically, often with a maculopapular rash that may resemble bug bites, and few or no vesicles.
Chickenpox in a vaccinated person is much milder than chickenpox in an unvaccinated person. Vaccinated children with breakthrough chickenpox disease usually have a low-grade or no fever, and fewer than 50 lesions.