BACKGROUND: School-based influenza vaccination campaigns could mitigate the effects of influenza epidemics. A large countywide school-based vaccination campaign was launched in Knox County, Tennessee, in 2005. Assessment of campaign effects requires identification of appropriate control populations. We hypothesized that contiguous counties would share similar pre-campaign patterns of influenza activity. METHODS: We compared the burden of influenza emergency department (ED) visits and hospitalizations between Knox County (Knox) and eight counties surrounding Knox (Knox-surrounding) during five consecutive pre-campaign influenza seasons (2000-01 through 2004-05). Laboratory-defined influenza seasons were used to measure the weekly incidence of medically attended acute respiratory illnesses (MAARI) attributable to influenza in school-aged children 5-17 years old (campaign target) as well as in other age groups. Seasonal rates of MAARI attributable to influenza for Knox and Knox-surrounding counties were compared using rate ratios. RESULTS: During five consecutive influenza seasons, MAARI attributable to influenza showed synchronous temporal patterns in school-aged children from Knox and Knox-surrounding counties. The average seasonal rates of ED visits attributable to influenza were 12.37 (95% CI: 10.32-14.42) and 13.14 (95% CI: 11.23-15.05) per 1000, respectively. The respective average seasonal influenza hospitalization rates for Knox and Knox-surrounding were 0.38 (95% CI: 0-0.79) and 0.46 (95% CI: 0.07-0.85) per 1000 children. Rate ratio analyses indicated no significant differences in the incidence of MAARI attributable to influenza between school-aged children from Knox and Knox-surrounding counties. Estimates for other age groups showed similar patterns. CONCLUSION: Before the Knox school-based influenza vaccination campaign, influenza resulted in an average of about 12 ED visits and 0.4 hospitalizations per 1000 school-aged children annually in Knox County. Since similar morbidity was observed in surrounding counties, they could serve as a control population for the assessment of the campaign effects.
BACKGROUND: School-based influenza vaccination campaigns could mitigate the effects of influenza epidemics. A large countywide school-based vaccination campaign was launched in Knox County, Tennessee, in 2005. Assessment of campaign effects requires identification of appropriate control populations. We hypothesized that contiguous counties would share similar pre-campaign patterns of influenza activity. METHODS: We compared the burden of influenza emergency department (ED) visits and hospitalizations between Knox County (Knox) and eight counties surrounding Knox (Knox-surrounding) during five consecutive pre-campaign influenza seasons (2000-01 through 2004-05). Laboratory-defined influenza seasons were used to measure the weekly incidence of medically attended acute respiratory illnesses (MAARI) attributable to influenza in school-aged children 5-17 years old (campaign target) as well as in other age groups. Seasonal rates of MAARI attributable to influenza for Knox and Knox-surrounding counties were compared using rate ratios. RESULTS: During five consecutive influenza seasons, MAARI attributable to influenza showed synchronous temporal patterns in school-aged children from Knox and Knox-surrounding counties. The average seasonal rates of ED visits attributable to influenza were 12.37 (95% CI: 10.32-14.42) and 13.14 (95% CI: 11.23-15.05) per 1000, respectively. The respective average seasonal influenza hospitalization rates for Knox and Knox-surrounding were 0.38 (95% CI: 0-0.79) and 0.46 (95% CI: 0.07-0.85) per 1000 children. Rate ratio analyses indicated no significant differences in the incidence of MAARI attributable to influenza between school-aged children from Knox and Knox-surrounding counties. Estimates for other age groups showed similar patterns. CONCLUSION: Before the Knox school-based influenza vaccination campaign, influenza resulted in an average of about 12 ED visits and 0.4 hospitalizations per 1000 school-aged children annually in Knox County. Since similar morbidity was observed in surrounding counties, they could serve as a control population for the assessment of the campaign effects.
Authors: Derek Weycker; John Edelsberg; M Elizabeth Halloran; Ira M Longini; Azhar Nizam; Vincent Ciuryla; Gerry Oster Journal: Vaccine Date: 2005-01-26 Impact factor: 3.641
Authors: H S Izurieta; W W Thompson; P Kramarz; D K Shay; R L Davis; F DeStefano; S Black; H Shinefield; K Fukuda Journal: N Engl J Med Date: 2000-01-27 Impact factor: 91.245
Authors: Robert B Belshe; Kathryn M Edwards; Timo Vesikari; Steven V Black; Robert E Walker; Micki Hultquist; George Kemble; Edward M Connor Journal: N Engl J Med Date: 2007-02-15 Impact factor: 91.245
Authors: Katherine A Poehling; H Keipp Talbot; John V Williams; Yuwei Zhu; John Lott; Lori Patterson; Kathryn M Edwards; Marie R Griffin Journal: Vaccine Date: 2009-02-24 Impact factor: 3.641
Authors: William W Thompson; David K Shay; Eric Weintraub; Lynnette Brammer; Carolyn B Bridges; Nancy J Cox; Keiji Fukuda Journal: JAMA Date: 2004-09-15 Impact factor: 56.272
Authors: Pedro A Piedra; Manjusha J Gaglani; Claudia A Kozinetz; Gayla B Herschler; Charles Fewlass; Dianne Harvey; Nadine Zimmerman; W Paul Glezen Journal: Pediatrics Date: 2007-08-13 Impact factor: 7.124
Authors: Donald R Olson; Richard T Heffernan; Marc Paladini; Kevin Konty; Don Weiss; Farzad Mostashari Journal: PLoS Med Date: 2007-08 Impact factor: 11.069
Authors: Nicole E Basta; Dennis L Chao; M Elizabeth Halloran; Laura Matrajt; Ira M Longini Journal: Am J Epidemiol Date: 2009-08-13 Impact factor: 4.897
Authors: Pete Riley; Michal Ben-Nun; Richard Armenta; Jon A Linker; Angela A Eick; Jose L Sanchez; Dylan George; David P Bacon; Steven Riley Journal: PLoS Comput Biol Date: 2013-05-16 Impact factor: 4.475