The study doesn't actually state that, it is much more nuanced. Since you didn't provide a proper reference to the study, forum readers can't check your statement right away, unfortunately.Margherita wrote: About Bartonella:
A study, effected in 1999 by the National Institue of Health in my country resulted as follows:
45% of ticks was infected with Erlichia
13% of ticks was infected with Borrelia
70% of ticks was infected with Bartonella !!
The 1999 study is this one:
Schouls LM, Van De Pol I, Rijpkema SG, Schot CS. Detection and identification of Ehrlichia, Borrelia burgdorferi sensu lato, and Bartonella species in Dutch Ixodes ricinus ticks. J Clin Microbiol. 1999 Jul;37(7):2215-22.
Here is the full text: http://jcm.asm.org/content/37/7/2215.long
The abstract says:
The full text says:In more than 70% of the ticks 16S rRNA gene sequences for Bartonella species or other species closely related to Bartonella were found.
Got that?Sequencing of 11 of the products obtained by PCR for Bartonella revealed that none represented B. henselae or B. quintana but closely resembled Bartonella vinsonii. However, the region of the 16S rRNA gene that was used for the PCR for Bartonella does not carry enough variation to reliably distinguish B. vinsoni from other closely related Bartonella and Rhizobiumspecies.
Also very relevant are the following pieces of information:
I. ricinus ticks were collected from infested roe deer (Capreolus capreolus) shot in the Flevopolder in The Netherlands, an area where roe deer are abundant.
Who understands why this is relevant?The majority of the ticks were adults, mainly females; and some were nonengorged, some were semiengorged, and some were fully engorged.
Besides all this, AFAIK it is still not established that Bartonella can be transmitted by ticks to humans, cause an infection and disease.