Bed bugs are a global problem, yet we still know so little about how they spread

• Bed bugs have recently exploded into the limelight amid widespread reports of a major outbreak in Paris.
• The more people share photos of bed bug bites on social media, the more concerned we feel.
• Indeed, data that confirms or denies the location and date of any bed bug cases is notoriously hard to find.

A seasonal spike

• The same seasonal pattern and year-on-year increase was seen in the US city of Philadelphia between 2009 and 2011, and in two Chinese cities in 2012/13.
• In New York between 2010 and 2020, the seasonal pattern was the same but the numbers did not increase.
• Studies from the US and Australia both found the same seasonal pattern in internet searches for bed bugs, although the pattern in Australia was the opposite to the northern hemisphere.

What we know about bed bugs

• It was much later in 1758 that the natural historian Carl Linnaeus added “lectularius” to their name, meaning bed or couch.
• Bed bugs have a complex gut microbiota, which helps them extract all the nutrients they need from our blood.
• My team put bed bugs in corrugated filter paper in the centre of a room, with clean and dirty clothes evenly spaced around them.
• The bed bugs all left the filter paper, and made a beeline for the dirty clothes nearly every time.

How to stop their spread

• If we could understand more about bed bug dispersal and spatial distribution, we would stand a better chance of stopping their spread.
• According to the same report that confirmed the 2010 outbreak, bed bug numbers in New York are declining.
• The city also passed a policy where, from 2010, landlords were required to report bed bug infestations to prospective tenants.

William Hentley is affiliated with the University of Sheffield. He receives funding from the University of Sheffield.