ResearchBlogging.orgSchool_childrenChildren have a very important role transmitting the Influenza virus. Since they had less contact with the virus, their immune reaction is lower and less effective; therefore, during the infection they have a higher viral load. A higher viral load associated with contact with several other children from different places in the same school, playing very close to each other, is a successful way of spreading the flu.

All of it raises the doubt on how effective school closings can be during an epidemic. Weights against the great loss caused by the posterior replacement of missed classes and the parents that miss work in order to keep company to their children.

Best data available are related to vacation periods; a cyclic and pre-established event which decreases the contact among children due to school breaks. In France, in addition to that, vacations are independent in three regions in the country and happen in different periods every year. Thanks to this kind of variety, environmental conditions such as the climate interfere less with measures of the effect of vacations in flu outbreaks.

Quantifying medical notes about respiratory infections in the period of 1984 to 2008, French and English investigators used very robust statistics to evaluate the influence of closing schools and create hypothesis about the relevance of this measure during an epidemic. With such action, they managed to show that a period of two weeks of vacations is enough to reduce about 20% of Influenza cases.

Assuming there is a pandemic wherein the proportion of people susceptible is 100%, i.e., there is no immunity of any kind against the virus in the population; fast school closings can decrease about 15% the total amount of cases, with a decrease of over 40% of sick people during peak period.

It is important to stress that a period more extensive than a couple of weeks can make it impracticable to isolate the children, and that several factors will also interfere. Events like Christmas and New Year’s holiday have major influence over people circulation, as well as the seasons interfere with spreading the virus, which is a lot more during winter time in European countries.

Simulation data and estimates allied to examples of actual events, such as a school closing in Hong Kong due to the death of three children (apparently because of Influenza) indicate that the contact among children during a flu epidemic may decrease damages. A piece of information that needs to be taken into account immediately when it comes to decisions being made during an outbreak.

Source:

Cauchemez, S., Valleron, A., Boëlle, P., Flahault, A., & Ferguson, N. (2008). Estimating the impact of school closure on influenza transmission from Sentinel data Nature, 452 (7188), 750-754 DOI: 10.1038/nature06732