526. Pilot Study of Elementary School-Located Influenza Vaccination, Absenteeism and Laboratory Confirmed Influenza
Session: Poster Abstract Session: Influenza Vaccines
Friday, October 21, 2011
Room: Poster Hall B1
Background: Studies of school-located influenza vaccination have measured impact on absenteeism, a nonspecific endpoint. Laboratory confirmed influenza is more specific, but unbiased case ascertainment is difficult. We conducted a pilot study in 4 elementary schools to assess the feasibility of influenza testing in this setting, and to compare the incidence of confirmed influenza and absenteeism.

Methods: School-located influenza vaccination was offered in two schools (982 students) by a local public health agency during October 2010; two similar schools (658 students) served as a comparison group. Parents were invited to provide consent for the schools to share individual absenteeism data. All-cause absences (ACA) and absences due to fever or cough (FCA) were monitored for all students for 12 weeks (Jan-Mar 2011). During the 4 weeks of peak influenza activity, consented students with FCA were offered testing for influenza by reverse transcription polymerase chain reaction (RT-PCR).

Results: At least one dose of vaccine was administered to 384 (39%) of 982 students during the school-located clinics. Overall influenza vaccine coverage was about 1.6 times higher in the vaccine clinic schools relative to the comparison schools. The incidence of ACA during the 12 week influenza season was 28.4 and 37.8 per 1,000 child-days in the vaccine clinic schools and comparison schools, respectively. Among all students, the incidence of FCA was 7.7/1,000 and 14.5/1,000 child-days in the intervention and comparison schools, respectively. Consent to share individual absenteeism data was given by 57% of parents. During the 4 week period of peak activity, 68 (69%) of 98 contacted students with absence due to fever or cough were tested for influenza. Six (9%) were positive (3 type A and 3 type B).

Conclusion: Assessment of influenza incidence in elementary schools is challenging due to the need for two separate consenting procedures (tracking absenteeism and consent to swab), low acceptance of school-located vaccination, difficulty tracking reasons for absenteeism, and unpredictable variation in the severity of influenza seasons. Novel strategies are needed to accurately assess the direct and indirect effects of influenza vaccination in school settings.


Subject Category: I. Adult and Pediatric Vaccines

Edward Belongia, MD, Marshfield Clinic Res. Fndn., Marshfield, WI, Sonia Kjos, PhD, Marshfield Clinic Res Fndn, Marshfield, WI, Stephanie Irving, MHS, Epidemiology Research Center, Marshfield Clinic Research Foundation, Marshfield, WI, Jennifer Meece, PhD, Marshfield Clin Res Fndn, Marshfield, WI and David K. Shay, MD, MPH, Centers for Disease Control and Prevention, Atlanta, GA

Disclosures:

E. Belongia, None

S. Kjos, None

S. Irving, None

J. Meece, None

D. K. Shay, None

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