The Rio Olympics are nearly upon us, but one of the biggest stories is not about sport, but about the dangers posed to athletes and spectators by an emerging disease. Zika virus hit the news in 2015 after it appeared in Brazil and was associated with microcephaly - reduced brain size - in new-borns. Since then, it has spread across South and Central America, Mexico, and the Caribbean, with the help of day-flying mosquitoes. Research has confirmed the link between the virus and abnormal brain development, and suggested that the virus might also be spread through sexual activity.
Zika virus is just the latest in a list of emerging diseases that have caused widespread alarm - from bird flu to Ebola. All of these diseases, and the pathogens that cause them, have spread around the world largely through human activity. However, pathogens and diseases of humans are just the tip of the iceberg - humans are also good at moving diseases of other animals and plants around the globe.
Recent work by Lena Wilfert showed how Deformed Wing Virus - yes, it does what it says on the tin - spread through the global honey bee population due to human movement of bees and bee products. But the virus didn’t do this on its own - it was helped out by another well-named parasite, the blood-sucking mite Varroa destructor, which also spread globally due human commerce.
While Deformed Wing Virus is a major threat to honey bees, work done in my lab by Matthias Fürst, in collaboration with Robert Paxton’s lab in Halle, suggested that it was being spread from managed honey bees to wild bumblebees. This could be a major threat to wild bee populations, as in other work we found that bumble bees infected with the virus lived less long. This might seem a little esoteric - yes, bumblebees are nice, but should they be on the top of the list of things we care about? - but, in fact, many fruits, nuts, and other crops that are core to our diet rely on wild bumblebees to pollinate them. So, viruses in wild bees may be an indirect threat to human health.
In our new project - a collaboration with Lena Wilfert in Exeter, Michelle Fountain at NIAB-EMR, and Claire Carvell at CEH - we are asking how viruses move between honey bees and wild bees, and how this is affected by wild-flower plantings put into agricultural fields with the aim of helping bees and other flower-visiting insects. It would be ironic if more flowers meant more disease…