# 4087
You don’t have to be an epidemiologist to know that schools are hotbeds of respiratory illness each winter, and that kids are very efficient spreaders of viruses.
It was for that reason that in early pandemic planning – particularly when considering a high mortality virus such as H5N1 – school closures for up to 12 weeks were prominently featured.
Once it was established that the novel H1N1 virus was nowhere near as virulent as bird flu, social policy in most countries was to try to keep schools open as much as possible.
While it has been assumed that closing schools would help curb the spread of a pandemic virus, until now there has been very little research that quantifies the benefit.
Something that we really ought to know before the next pandemic virus emerges.
Today we get a study, published in the open access journal BMC Infectious Diseases, that finds that forced school closures can reduce secondary infections by roughly 20%.
This study makes the assumption that social mixing and interaction during a pandemic induced school closure would mimic social contacts currently seen during routine weekend and holiday school closures.
Their estimates, therefore, are probably conservative. Social distancing beyond just the closure of schools would likely be taking place, and large social gatherings probably discouraged.
School closings have costs, both economic and social, and those have to be taken into account as well. Forced school closings are not something to be done lightly.
During a severe pandemic wave, however, this study makes a pretty good case for the closing of schools to significantly lower the attack rate.
Estimating the impact of school closure on social mixing behaviour and the transmission of close contact infections in eight European countries
Niel Hens , Girma Minalu Ayele , Nele Goeyvaerts , Marc Aerts , Joel Mossong , John W Edmunds and Philippe Beutels
BMC Infectious Diseases 2009, 9:187doi:10.1186/1471-2334-9-187
Published:
27 November 2009Background
Mathematical modelling of infectious disease is increasingly used to help guide public health policy. As directly transmitted infections, such as influenza and tuberculosis, require contact between individuals, knowledge about contact patterns is a necessary pre-requisite of accurate model predictions. Of particular interest is the potential impact of school closure as a means of controlling pandemic influenza (and potentially other pathogens).
Methods
This paper uses a population-based prospective survey of mixing patterns in eight European countries to study the relative change in the basic reproduction number (R0 - the average number of secondary cases from a typical primary case in a fully susceptible population) on weekdays versus weekends and during regular versus holiday periods. The relative change in R0 during holiday periods and weekends gives an indication of the impact collective school closures (and prophylactic absenteeism) may have during a pandemic.
Results
Social contact patterns differ substantially when comparing weekdays to the weekend and regular to holiday periods mainly due to the reduction in work and/or school contacts. For most countries the basic reproduction number decreases from the week to weekends and regular to holiday periods by about 21% and 17%, respectively. However for other countries no significant decrease was observed.
Conclusions
We use a large-scale social contact survey in eight different European countries to gain insights in the relative change in the basic reproduction number on weekdays versus weekends and during regular versus holiday periods. The resulting estimates indicate that school closure can have a substantial impact on the spread of a newly emerging infectious disease that is transmitted via close (non sexual) contacts.
The complete article is available as a provisional PDF. The fully formatted PDF and HTML versions are in production.
