School Closure Could Drastically Slow Avian Flu Spread

Using computer modelling, researchers from the MRC Centre for Outbreak Analysis and Modelling at Imperial College London, working with colleagues in France, found that closing schools would affect the spread of a theoretical pandemic H5N1 avian flu virus which had mutated to pass between humans. It was found that school holidays where schools were closed does change the pattern of flu transmissions in France. The new study shows that closing schools for long periods of time could prevent up to one in every seven cases. They also say that closing schools would slow and reduce a pandemic, lowering the numbers becoming ill in the worst week of the outbreak by up to 40%. This alone could take the stress off of health care providers and hospitals.

However, the researchers caution that closing schools for a prolonged period would be a very costly measure, particularly because of its impact on working parents. Taking away the childcare that schools provide could also affect the spread of the virus, in ways that are difficult to model using existing information.

The example they gave was that with the closure of schools, placing the children in childcare while parents went to work, could still spread the virus. As well, for those in the medical profession, the amount of available health care personnel would drop if they had to stay home with their own children.

"Our research shows that school closures could be a useful measure in terms of slowing the spread of a flu pandemic. However, its effectiveness would very much depend on what other measures, like vaccination or antiviral drugs, were put in place as well," said Dr. Simon Cauchemez, one of the authors of the study.

Another author, Professor Neil Ferguson, from the MRC Centre for Outbreak Analysis and Modelling at Imperial College London added that closing schools is an option that can't be taken

"lightly because it has a big economic and social impact, and the extent to which there would be a knock-on effect on transmission is hard to predict."

What's been made clear is that even though the children weren't in school, they would be in contact with other children and adults, and this would continue the spread rather than slow it, because of the need for parents to still have their children watched while they worked. Analysing data collected since 1984 by 1,200 GPs in France, is how the researchers derived the their numbers, specifically how the virus spread while children were off school on holidays. This data showed that holidays lead to a 20-29% reduction in the rate at which influenza is transmitted to children, but that they have no detectable effect on the contact patterns of adults. The French data also revealed that children were responsible for around 46% of all infections. Then, the researchers extrapolated from that data to find out how school closures did affect the spread of the virus should there be a pandemic in France.

At present, the H5N1 strain of influenza is transmitted to people by birds and person-to-person transmission is very rare. However, the virus is so lethal that if it were to mutate and become more transmissible, as in the researchers' new model, the consequences of a global pandemic could be disastrous.