Influenza is an airborne viral disease that, according to the World Health Organisation, can cause 250,000 to 500,000 deaths each year. In the UK, £1.2 bn was spent preparing for last winter’s swine flu pandemic. Although an independent review described this response as “proportionate and effective”, around 34 million doses of swine flu vaccine were stockpiled and never used.
In Geography Compass, Christopher Furhmann asks whether we can predict the spread and scale of influenza outbreaks more accurately. Influenza outbreaks commonly occur in winter, so Furhmann investigates a connection with weather and climate. However, no clear causal link between climate and influenza (in terms of the timing of an epidemic, its severity or spatial distribution) is found.
Furhmann argues that there are three obstacles to establishing whether influenza is climate controlled. The first is that researchers vary in their approaches to studying the disease. The extent to which clinical tests can be applied outside of laboratory controlled conditions is uncertain. Second, it is unclear whether increases in winter mortality rates are a result of influenza itself or complications arising from the disease. Third, direct climate effects on the influenza virus and its transmission are complicated by indirect effects on human behaviour. This creates uncertainties over the impacts of a changing climate on disease.
This complexity creates a need for a multidisciplinary approach to researching influenza, something that geographers are well placed to engage with.
BBC News coverage of swine flu, from which many of the statistics quoted here are drawn.
Christopher Furhmann (2010) “The effects of weather and climate on the seasonality of influenza: what we know and what we need to know.” Geography Compass 4 (7): 718-730