Send your sick colleague home – but don’t hire a replacement
Research from Nature Physics shows how infectious diseases spread through social networks
As someone who gets a bad cold pretty much every year, I am the first to send a loudly sneezing or coughing colleague home. Firstly, they will get better quicker and are unlikely to be productive in the office; secondly they won’t infect all their colleagues, including me. This is fine in the UK, where I work, but is a challenge in the USA and some other countries where policies on sick leave are less generous, leading some to call for paid sick days to reduce the spread of influenza. There are also challenges when your sick colleague does an essential job, like a teacher or a nurse, as you will need to find cover for them.
An interesting take on this latter dilemma has been published today in Nature Physics, where Samuel Scarpino and colleagues at the Santa Fe Institute, University of Vermont and Universitat de Barcelona model the spread of infectious disease through social networks. They show that replacing an infected individual with a healthy cover (e.g. a locum doctor, or a substitute teacher) can actually speed up the spread of disease. This is because the replacement is probably entering a more dangerous situation than they were in before – i.e. they are put into an environment where someone (the sick colleague) has already caught the infection. This policy of replacing sick individuals with healthy ones, called relational exchange, causes a disease to spread more quickly at the start of an epidemic than one would expect.
They tested their model of accelerated spread against empirical data from influenza and dengue outbreaks. The model fit with 17 influenza outbreaks in the USA, 25 years of influenza data from New Mexico and 19 years of dengue virus data from Puerto Rico.
What does this mean for your workplace? The authors say that this makes an even stronger case for vaccination of key workers against diseases such as influenza. NHS staff in the UK are offered the flu vaccine, but uptake could be higher. It also suggests that replacement workers such as substitute teachers may experience high rates of illness – something worth looking into.
The paper is available here: http://nature.com/articles/doi:10.1038/nphys3832