The Epidemiology of Measles in New York City (NYC) in 2008 and the Use of An Immunization Information System (IIS) in Outbreak Control

Background:
In 2008, NYC had the largest number of measles cases since 1992. The majority of these cases occurred in four zip codes in Brooklyn.

Objectives:
Describe the epidemiology of measles cases in NYC in 2008 and present the use of NYC's IIS in outbreak control activities. .

Methods:
Cases of measles were reported as part of routine vaccine preventable disease surveillance activities. NYC's IIS was used to target providers and parents of unvaccinated children living in the most affected communities.

Results:
There have been 29 confirmed or probable cases of measles in NYC in 2008: 24% were <1 year, 28% between 12-15 months, 14% between 16-59 months, and 34% were >18 years. No cases were between 5-18 years of age. Five cases (17%) were imported; among the remaining 24 cases, 67% (16/24) occurred in 4 contiguous ZIP Codes. Six of the seven cases among children <1 year, and seven of eight among those 12-15 months, occurred in those four ZIP Codes. To target control measures we used the NYC IIS to identify the practices in those ZIP Codes (n=67), inform them of the outbreak, recommend control measures, and provide a list of children missing a measles-containing vaccine for recall. In addition, the IIS was used to generate a list of 7,312 children 12-59 months of age residing in the targeted area and having no measles-containing vaccine. A letter was sent informing parents about the outbreak and need for their children to be vaccinated.

Conclusions:
Measles remains a threat while there continues to be circulation in other parts of the world. Even in a population vaccinated ‘on-time', the cohort of children <15 months may be enough to sustain transmission. IISs can be an important tool in outbreak control allowing intensive and targeted control messages particularly in situations of geographic clustering.