Greetings! Since my last update I have been working in the lab to clear up some inconclusive results on three bird blood samples (see last update here). It took a lot longer than I would have liked, basically due to things like this, and this. However, after finally optimizing the assays, one of the three equivocal samples tested positive for Borrelia.
We opted to test these samples by conventional PCR and gel electrophoresis (as opposed to the real-time PCR in the first round). This more crude method, while less sensitive, allowed us to physically see a band form on the gel if the pathogen was present. We then performed DNA sequencing to confirm that the band that we were seeing was in fact from the Borrelia genus. The sample that tested positive for Borrelia was taken from an Eastern Phoebe, a migratory species that spends its summers anywhere from Northern Canada to the midwest and Eastern US, and winters in Mexico.With this one positive out of a sample of 69 birds, the infection rate observed is 1.45%. While this can't be reliably applied to a larger scale given the small sample size, the rate is comparable to other studies that have looked at the prevalence of Lyme in birds.
Currently, we're still investigating to determine exactly what species of Borrelia was found in the Phoebe's blood. So far, all of the potential species look to be part of the Borrelia burgdorferi sensu lato group - meaning that they're all infectious to humans.
Our final step is to definitively determine the species we uncovered in the Phoebe, and to publish the study. Stay tuned!