This e-pub ahead of print has sent the media into a tizzy, and why would it not! Consider the power of this headline in your morning newspaper:
“FLESH EATING BACTERIA ISOLATED FROM BED BUGS”
Now that the zombie apocalypse has failed, there must be some new fad to sell papers, and this seems like something that might just do the trick.
The results are undoubtedly very interesting and one must praise the innovativeness of the researchers in coming up with the brilliant research question. However, there seem to be no reason right now in getting all freaked out and start burning down your beds or something.
For one thing, this study is more like a hypothesis generating effort, if anything. The sample size is incredibly small: 5 bedbugs harvested off 3 patients. With such small numbers at stake, all one can say is that there is evidence demanding further studies, and extrapolating it any further could be erroneous.
The researchers looked for Methicillin Resistant Staphylococcus aureus and Vancomycin Resistant Enterococcus and here is what the found:
For 2 patients, VRE was isolated from 1 bedbug each. These bacterial isolates were also resistant to ampicillin, teicoplanin, and aminoglycosides but susceptible to linezolid, quinupristin/dalfopristin, and tetracycline. For 1 other patient, MRSA was isolated from 3 bedbugs. All MRSA isolates had susceptibility patterns consistent with pulsed-field gel electrophoresis type USA300 (susceptible to vancomycin, clindamycin, trimethoprim/sulfamethoxasole, tetracycline, and rifampin; resistant to erythromycin).
Bedbug bites have classically been associated with cutaneous allergic responses, like Bullous Allergic hypersensitivity, like in this case reported in the Journal of Investigative Dermatology (1):
Another thing which goes against the sensationalism portrayed by the journalists is the fact that the bedbugs were homogenized and streaked onto culture media for isolation of the bacteria concerned. This introduces the following issues:
- Were the bed bugs colonized transiently?
- What would be the risks of transmission of the bacteria on a single blood meal by an infected vector? The study does not provide evidence that the bed bugs are so colonized that a blood meal would mean dissemination of the bacteria
- What exactly is the nature of the association? This is especially important, since one cannot stress the importance of the fact that just isolation of the bug is not equivalent to establish vectoral relationship enough.
Whatever be the case, there is no room for the speculative and sensationilistic journalism that has spawned in and around this paper.
Another blog worth reading on this issue: Aetiology (that’s where I got whiff of this paper!).
1. Leverkus M, Jochim RC, Schad S, et al. Bullous Allergic Hypersensitivity to Bed Bug Bites Mediated by IgE against Salivary Nitrophorin. Journal of Investigative Dermatology (2006) 126, 91–96. doi:10.1038/sj.jid.5700012
Christopher F. Lowe, & Marc G. Romney (2011). Bedbugs as Vectors for Drug-Resistant Bacteria Emerging Infectious Diseases : 10.3201/eid1706101978