The Lancet Review 2009:
Lancet Infect Dis 2009; 9: 473–81
www.thelancet.com/infection Vol 9 August 2009
Pages: 473-481
Closure of schools during an influenza pandemic
Simon Cauchemez, Neil M Ferguson, Claude Wachtel, Anders Tegnell, Guillaume Saour, Ben Duncan, Angus Nicoll
http://download.thelancet.com/flatcontentassets/H1N1-flu/prevention/prevention-18.pdf
Excerpt:
"Conclusions and implications for the mitigation
of the H1N1 pandemic
In this Review, we have taken a multidisciplinary and
holistic perspective in reviewing school closure as a
public health policy in an infl uenza pandemic.
Two historical studies (holidays in France and the
experience of US cities in 1918) provide information on
the likely maximum health eff ect of school closure in
past epidemics and pandemics, each of them come with
their own limitations. Those two datasets suggest that, in
an optimistic scenario, closure of schools during a
pandemic might have some eff ect on the total number of
cases (maybe a 15% reduction), but cause larger
reductions (around 40%) in peak attack rates. However,
this reduction will be substantially undermined if
children are not suffi ciently isolated or if the policy is not
well implemented. The 2008 Hong Kong outbreak, the
French experience during the 1957 pandemic, and the
1918 pandemic records in some US cities show that a
failure to have any discernible eff ect is possible, especially
if decisions come too late. It is also possible to hypothesise
perverse eff ects such as an increase in mortality in older
people if they are engaged to care for children when
schools close.
However, estimates of health eff ect derived from past
pandemics and epidemics are not necessarily relevant for
H1N1. Indeed, comparison of the 1918, 1957, and 1968
pandemics shows that there is no such thing as a standard
pandemic. On the bases of illness attack rates and reports
of illness in children (fi gure 3), it seems that school
closure might have had a substantial eff ect in 1957 when
much transmission took place among children, some
eff ect in 1918, but a lesser eff ect in 1968 when illness
attack rates were similar among children and adults. In
the early stage of the H1N1 pandemic, the large proportion
of children among cases so far,4,5 and the large number of
case clusters in schools strongly suggest that the
reduction in the number of cases because of school
closure in this specifi c pandemic will be stronger than
would be expected from observations based on seasonal
infl uenza.14
The intervention has a high economic cost, with two
estimates available in the published work: up to 1% of
British GDP for a 12-week school closure25 and 6% of
US GDP.26 School closure also raises a range of ethical
and social issues, particularly since families from
underprivileged backgrounds are likely to be
disproportionately aff ected by the intervention.
In a severe pandemic, countries might be ready to pay
those high social and economic costs to benefi t from the
potential reduction in cases. But they should very
carefully consider the eff ect that the intervention might
have on key workers, education, and on crisis
management capacity. For example, school closure might
lead to important reductions in the peak incidence of
cases, therefore reducing health-care system burden
when the stress on the service is maximum. But this
should be weighed against the potential disruption
caused to the health services because of increased
absenteeism of the workforce.
The decision to close schools must be made on the basis
of the severity of the pandemic. This is illustrated by the
..."
Lancet Infect Dis 2009; 9: 473–81
www.thelancet.com/infection Vol 9 August 2009
Pages: 473-481
Closure of schools during an influenza pandemic
Simon Cauchemez, Neil M Ferguson, Claude Wachtel, Anders Tegnell, Guillaume Saour, Ben Duncan, Angus Nicoll
http://download.thelancet.com/flatcontentassets/H1N1-flu/prevention/prevention-18.pdf
Excerpt:
"Conclusions and implications for the mitigation
of the H1N1 pandemic
In this Review, we have taken a multidisciplinary and
holistic perspective in reviewing school closure as a
public health policy in an infl uenza pandemic.
Two historical studies (holidays in France and the
experience of US cities in 1918) provide information on
the likely maximum health eff ect of school closure in
past epidemics and pandemics, each of them come with
their own limitations. Those two datasets suggest that, in
an optimistic scenario, closure of schools during a
pandemic might have some eff ect on the total number of
cases (maybe a 15% reduction), but cause larger
reductions (around 40%) in peak attack rates. However,
this reduction will be substantially undermined if
children are not suffi ciently isolated or if the policy is not
well implemented. The 2008 Hong Kong outbreak, the
French experience during the 1957 pandemic, and the
1918 pandemic records in some US cities show that a
failure to have any discernible eff ect is possible, especially
if decisions come too late. It is also possible to hypothesise
perverse eff ects such as an increase in mortality in older
people if they are engaged to care for children when
schools close.
However, estimates of health eff ect derived from past
pandemics and epidemics are not necessarily relevant for
H1N1. Indeed, comparison of the 1918, 1957, and 1968
pandemics shows that there is no such thing as a standard
pandemic. On the bases of illness attack rates and reports
of illness in children (fi gure 3), it seems that school
closure might have had a substantial eff ect in 1957 when
much transmission took place among children, some
eff ect in 1918, but a lesser eff ect in 1968 when illness
attack rates were similar among children and adults. In
the early stage of the H1N1 pandemic, the large proportion
of children among cases so far,4,5 and the large number of
case clusters in schools strongly suggest that the
reduction in the number of cases because of school
closure in this specifi c pandemic will be stronger than
would be expected from observations based on seasonal
infl uenza.14
The intervention has a high economic cost, with two
estimates available in the published work: up to 1% of
British GDP for a 12-week school closure25 and 6% of
US GDP.26 School closure also raises a range of ethical
and social issues, particularly since families from
underprivileged backgrounds are likely to be
disproportionately aff ected by the intervention.
In a severe pandemic, countries might be ready to pay
those high social and economic costs to benefi t from the
potential reduction in cases. But they should very
carefully consider the eff ect that the intervention might
have on key workers, education, and on crisis
management capacity. For example, school closure might
lead to important reductions in the peak incidence of
cases, therefore reducing health-care system burden
when the stress on the service is maximum. But this
should be weighed against the potential disruption
caused to the health services because of increased
absenteeism of the workforce.
The decision to close schools must be made on the basis
of the severity of the pandemic. This is illustrated by the
..."
