Bartonella is a formidable coinfection for many Lyme/MSIDS patients. Symptoms are largely associated with where blood flow is compromised:
Skin rashes (stretch-mark-like), cysts, heartburn, abdominal pain, chest pain, gastritis, duodentis, mesenteric adenitis, psychological issues (anxiety, anger, suicidal thoughts, depression, irritability), pain in the soles of the feet, skin tags and red papules, endocarditis, acute encephalopathy, seizures, visual and auditory hallucinations, ocular floaters, fatigue, partial paralysis, laryngitis, severe confusion, difficulty swallowing, muscle weakness, and vasculitis that occurs anywhere in the body which can destroy blood vessels. For a longer list of symptoms see: https://madisonarealymesupportgroup.com/2011/09/25/the-bartonella-checklist-copyrighted-2011-james-schaller-md-version-11/
Since it exists in very low amounts in human blood, blood tests are unreliable. It also has a long division time between 22-24 hours and requires a special growth environment. There is a Triple Draw through Galaxy which collects blood over 8 days to maximize the test, stating a 90% reduction in false negatives.
http://townsendletter.com/July2015/bartonellosis0715_3.html Vectors include fleas and flea feces, biting flies such as sand flies and horn flies, the human body louse, mosquitoes, mites, and ticks; through bites and scratches of reservoir hosts; and potentially from needles and syringes in the drug addicted. Needle stick transmission to veterinarians has been reported. There is documentation that cats have received it through blood transfusion.
Bartonella has recently been found in winged adult deer keds in Finland: https://www.ncbi.nlm.nih.gov/m/pubmed/24901607/?i=4&from=/23104416/related
Moose as reservoirs, deer keds as vectors in Norway: https://www.ncbi.nlm.nih.gov/m/pubmed/23104416/?i=2&from=/26967131/related
Bartonella infection in southern Finnish moose was 90.6% (inside the deer ked zone), while northern Finnish moose was 55.9% (outside the deer ked zone). At least two species of bartonellae were identified. https://www.ncbi.nlm.nih.gov/m/pubmed/26967131/
Just what are deer keds? In the fly family (6 legs), they will chuck their wings as soon as they land on a host to suck blood more easily. http://www.tickencounter.org/tick_notes/tick_notes_deer_keds
For more on Bartonella: