Background: The population served by Hershey Medical Center (HMC) has a unique demographic profile due to nearby Amish and Mennonite communities. Previous research demonstrates that these communities have lower immunization rates compared to the general population which allows for sporadic outbreaks of vaccine preventable diseases (VPD). We sought to describe characteristics of children diagnosed with pertussis, tetanus or varicella. <>Methods: ICD 9 codes were used to identify patients from birth to 5 years with a diagnosis of pertussis, and pediatric patients from birth to 18 years with a diagnosis of tetanus or varicella between January 2005 and December 2015. Chart reviews were performed to identify patient demographics, immunization history, and immune status. Patient characteristics were compared using Fishers exact test. Data analysis was performed using Stata 14. <>
Results: A total of 40 cases of VPD were identified (pertussis n=8, tetanus n=5, and varicella n=27). Most infections (62.5%) were in children who were not affiliated with a Plain community. More VPDs occurred in unvaccinated children than vaccinated children (62.5%, 37.5%, respectively, P<0.001).Most non-Plain children were vaccinated (15/25, 60%) and most Plain children were unvaccinated (14/15, 93%; 1 childs vaccine status was not documented). Half were immunocompromised (21/40, 53%) (Figure). All tetanus cases (n=5) occurred in non-vaccinated children and 4 (80%) belonged to a Plain community. Among the 8 cases of pertussis, 5 (63%) occurred in children who were receiving vaccines as recommended but were too young to have completed the pertussis series.
Conclusion: Most VPD occur in unvaccinated children. Plain children in our community are rarely immunized and remain at risk for VPD. Immunocompromise is a common predisposing factor for VPD in both Plain and non-Plain children. Further outreach to increase vaccination in high-risk, unimmunized populations may provide improved protection against VPDs through both individual and community immunity.
Figure. Frequency of immunocompromised for Plain and non-Plain children with pertussis, tetanus or varicella.
P. Kumar, None
J. E. Ericson, None