Establishing the baseline burden of influenza in preparation for the evaluation of a countywide school-based influenza immunization campaign

Carlos G. Grijalva, Yuwei Zhu, Lone Simonsen, Marie R. Griffin

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Resumé

Background
School-based influenza immunization campaigns could mitigate the effects of influenza epidemics. A large countywide school-based immunization 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 immunization 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.
OriginalsprogEngelsk
TidsskriftVaccine
Vol/bind29
Udgave nummer1
Sider (fra-til)123-129
ISSN0264-410X
StatusUdgivet - 2010

Citer dette

@article{1978fbb31773401d92445d0b8c9a3f43,
title = "Establishing the baseline burden of influenza in preparation for the evaluation of a countywide school-based influenza immunization campaign",
abstract = "BackgroundSchool-based influenza immunization campaigns could mitigate the effects of influenza epidemics. A large countywide school-based immunization 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.MethodsWe 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.ResultsDuring 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.ConclusionBefore the Knox school-based influenza immunization 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.",
author = "Grijalva, {Carlos G.} and Yuwei Zhu and Lone Simonsen and Griffin, {Marie R.}",
year = "2010",
language = "English",
volume = "29",
pages = "123--129",
journal = "Vaccine",
issn = "0264-410X",
publisher = "Elsevier Ltd",
number = "1",

}

Establishing the baseline burden of influenza in preparation for the evaluation of a countywide school-based influenza immunization campaign. / Grijalva, Carlos G.; Zhu, Yuwei; Simonsen, Lone; Griffin, Marie R.

I: Vaccine, Bind 29, Nr. 1, 2010, s. 123-129.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

TY - JOUR

T1 - Establishing the baseline burden of influenza in preparation for the evaluation of a countywide school-based influenza immunization campaign

AU - Grijalva, Carlos G.

AU - Zhu, Yuwei

AU - Simonsen, Lone

AU - Griffin, Marie R.

PY - 2010

Y1 - 2010

N2 - BackgroundSchool-based influenza immunization campaigns could mitigate the effects of influenza epidemics. A large countywide school-based immunization 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.MethodsWe 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.ResultsDuring 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.ConclusionBefore the Knox school-based influenza immunization 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.

AB - BackgroundSchool-based influenza immunization campaigns could mitigate the effects of influenza epidemics. A large countywide school-based immunization 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.MethodsWe 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.ResultsDuring 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.ConclusionBefore the Knox school-based influenza immunization 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.

M3 - Journal article

VL - 29

SP - 123

EP - 129

JO - Vaccine

JF - Vaccine

SN - 0264-410X

IS - 1

ER -