So the results of this study really caught me by surprise.
I'll try to summarize it the best way I can.
These were patients that showed signs of tick related diseases. So they tested them with PCR. Keyword here is PCR because there are problems with the accuracy of that, which I'll explain later and is also explained in the study itself.
One more thing, I haven't found where in what
location of the world the patients were. It seems like it's an European journal so I would think there.
These were the results:
Borrelia burgdorferi............0/104 (0%)
Borrelia miyamotoi............1/104 (0.96%)
Borrelia afzelii............1/104 (0.96%)
Borrelia hermsii............2/104 (1.92%)
Ehrlichia spp.............15/104 (14.42%)
Bartonella spp.............4/104 (3.85%)
Bartonella quintana............4/104 (3.85%)
Bartonella henselae............8/104 (7.7%)
Rickettsia spp.............31/104 (29.8%)
Babesia spp.............9/104 (8.65%)
Anaplasma spp.............0/104 (0%)
Francisella tularensis............0/104 (0%)
Brucella spp.............1/104 (0.96%)
Coxiella burnetii............3/104 (2.88%)
Chlamydia spp.............2/104 (1.92%)
Theileria spp.............11/33 (33.3%)
Mycoplasma spp.............91/104 (87.5%)
I personally had 3 questions after reading this:
- Why so little Lyme?
- Why so much Mycoplasma?
- Why so much Theileria and what is Theileria?
So the first question is why so little Lyme?
That doesn't correlate with other studies at all.
Luckily it explains in the conclusion:
It could be hypothesized that the frequency of Borrelia is lower than expected or that this bacterium is particularly difficult to detect. Borrelia could be present in deeper
locations in a wide range of organs (brain for example) and thus could not be detected in this study, despite the use of several matrices .
Something else I noticed is that although PCR tests are usually done with synovial fluids. This was not the case in this study it seems:
"were searched for in saliva, urine, venous and capillary blood by using real time PCR"
They also say these 2 things about
" This confirms data from previous studies that showed a low interest of venous blood PCR for the detection of Borrelia. "
"Some studies used PCR to identify B. burgdorferi in early Lyme disease, while we studied it in a chronic stage"
So I think it makes sense why it was so low, seems likely to be an issue with the tools they had.
Then the next question is the large amount of mycoplasma.
Which is really interesting:
"Some bacteria such as Mycoplasma spp. are not constantly transmitted by ticks and could be commensal bacteria. However, some mycoplasmas such as Mycoplasma fermentans can be transmitted by ticks and be pathogenic . Furthermore, Lyme disease can lead to a depression of the immune system , resulting in the occurrence of opportunistic infections, which could include Mycoplasma infections. These microorganisms, in particular Mycoplasma, could be transmitted by other sources than the tick bite, for example by sexual contamination. It might be thus more accurate to change the paradigm, and consider the term “crypto-infections” rather than exclusively “tick-borne infections” ."
I think the part about
opportunistic infections is interesting here.
It also makes me wonder how much mycoplasma just "hangs around" in people without any symptoms.
But one of the most interesting things in this study is probably the large amount of Theileria.
I had personally never heard of that.
It's a parasite usually seen in animals. In fact, this is the first study to isolate it from humans.
And it seems like they specifically did their best to isolate it from Babesia:
Theileria pathogen-specific PCR sequences, well known in veterinary medicine as it usually infests horses , were never isolated from humans. There is a very great genetic proximity between Babesia microti and Theileria microti and our PCR primers are studied to specifically isolate the genus Babesia from the genus Theileria. The fact that only Babesia species were known in human medicine is not an argument to say that theileriasis is not a human disease. A surprising result is that we isolated much more Theileria spp. than Babesia spp. These preliminary results suggest that Theileria could be a significant pathogen for humans. These results should be confirmed by additional studies.
In conclusion, I think this is a really interesting study and if you have the time and energy, it's worth looking through.
I like how the authors were
the limitations of the study because it explains some of the results.
I also think it's interesting to see the high amount of Theileria.