Bartonella is another frequently named co-infection. Although it really has not been established as coming from ticks, it is possible. Most commonly it is known as "Cat Scratch Fever." There are two forms of bartonella: B. henselae and B. quintana. There have been some other species discovered, but it is unclear whether or not they cause human disease.
The clinical manifestations of tick-transmitted bartonellosis are essentially unknown. They may resemble cat scratch disease, take other clinical forms, or be benign. It is also unclear if Bartonella co-infection with other tick-transmitted organisms can result in more serious illness. Some of the few reported cases of concurrent B. burgdorferi and B. henselae infection in the medical literature appear to suggest this could be the case. Thus, it may be prudent to consider the possibility of Bartonella co-infection in cases of poorly resolving or apparently relapsing Lyme disease.
But... Given the uncertainties surrounding the presentation and incidence of tick-transmitted bartonellosis, diagnosis cannot be made purely on clinical grounds. So, lab confirmation of infection is very important. Serological tests exist for Bartonella infections. The most common tests are immunofluorescent fluorescent antibody (IFA) assays for both IgM and IgG antibodies. Also, a PCR (polymerase chain reaction) from whole blood, tissue, or cerebrospinal fluid is highly accurate and very specific.
There are a number of less scrupulous practitioners pushing treatment for Bartonella. But "both schools" of lyme treatment agree.
Bartonella is sensitive to many different antibiotics in vitro (in the lab), but the in vivo (actual) performance of these antibiotics in humans and domestic pets does not correlate well with in vitro lab studies. Most likely, this is because: 1) almost all antibiotics are bacteriostatic against Bartonella, rather than bactericidal; and 2) the pathogen is often sequestered in the red blood cells.
Cat scratch disease usually resolves, even without treatment, and there is little evidence that antibiotics help patients heal more quickly. Thus, there is disagreement over whether or not antibiotic treatment is necessary for uncomplicated CSD. Tick-transmitted Bartonella may be a more serious matter, however, since the possibility of co-infection is always present. In addition, there is general agreement that the presence of B. henselae in cerebrospinal fluid, whatever its origin, warrants treatment.
CSD is most often treated with tetracyclines, macrolides or aminoglycosides. For CNS infection, antibiotics that cross the blood brain barrier are necessary, and combination therapy is usually recommended, as it may be more effective. Among the recommended regimens are azithromycin or doxycycline in combination with rifampin, clarithromycin or a fluoroquinolone. The optimal length of therapy has yet to be determined, but most guidelines suggest that treatment should last for at least 4-6 weeks.
If you have a practitioner claiming a complicated disease or serious symptoms as the result of Bartonella, RUN. It is easily diagnosed and treated. Bartonella is a gram-negative bacteria, so it will not and cannot create toxins. Should a practitioner claim you are "herxing," rest assured that it is the treatment that is making you sick. Again, RUN.
There are some very rare complications from bartonella, but there is no evidence or recorded cases where they have occurred much beyond a 5 -14 day window following initial infection. Those complications will not be resolved by treating the Bartonella months or years later.