Coming to a local news station near you: Bovine TB

Sure, its only in Britain at the moment, but so was Mad Cow until recently. is reporting that a specific strain of liver disease in cows actually obscures tests for bovine TB:

The liver fluke Fasciola hepatica was already known to affect the standard skin test for bTB, but it was unclear whether the fluke stopped the disease developing or merely hid the symptoms. A study published today in Nature Communications suggests that the latter is more likely, and that the effect is significant. It estimates that around a third of bTB cases in England and Wales are undiagnosed because the test is less sensitive in cattle infected with the fluke1.

The report goes on to say that the US, Canada and Australia have “eradicated” the liver fluke that is obscuring the test results. But you know how that goes.


Sending in the mosquitos: introduced species, anyone?

Researchers in the Australian state of Queensland are experimenting with introducing a virus into mosquitos to prevent another virus from spreading the deadly Dengue fever. The concept is pretty simple: Virus A spreads a deadly fever, Virus B prevents Virus A from reproducing, which basically eliminates Virus A from the equation. So, infect a bunch of mosquitos with Virus B and they’ll be able to prevent or at least mitigate the spread of a deadly disease. Great, right?

Not quite. Readers of my blog know that one concern I have is the idea of what ills an introduced species can have. The trouble is that the integration of native species generally has some sense of balance – always adjusting, always different, but still a sense of balance. When new species are introduced into the equation – or when one species has its population artificially increased – the results can be unexpected. Possibly even worse than the problem they were meant to solve.

For some fun background on introduced species, there is a series of videos on Youtube describing the troubles Australia already had with cane toads. But right here in the Rochester area, we have also had our recent problems with purple loosestrife as well. Here’s another video from a Wisconsin educator on the troubles they’ve had.

Its worth pointing out that similar types of bioengineering happen all the time. For example, many gardeners introduce ladybugs into their gardens to control mites. But when it happens on such a large scale – particularly with fast-reproducing and fast-evolving viruses – the concerns are a bit greater.

Modified mosquitoes set to quash dengue fever : Nature News & Comment.