Carrión developed the disease three weeks after the inoculation and kept a meticulous record of clinical symptoms and signs until the disease rendered him incapable of the task and he died at age 28 several weeks later—October 5, 1885. Carrión proved that Oroya fever and verruga peruana were two stages of the same disease, and not two different diseases as was thought at the time. His work did not result in a cure immediately, but his research started the process. Peru has named October 5 as "Peruvian Medicine Day" in his honor.Peruvian microbiologist Alberto Barton discovered the causative bacterium in 1905, but his results were not published until 1909. Barton originally identified them as "endoglobular" structures, bacteria living inside red blood cells. Until 1993, the genus Bartonella, within the family Bartonellaceae, contained only one species; 23 are now identified. CSD
In 1988, English et al. isolated and cultured a bacterium that was named Afipia felis in 1992 after the team at the Armed Forces Institute of Pathology that discovered it. This agent was considered the cause of cat-scratch Disease (CSD) but further studies failed to support this conclusion. Serologic studies associated CSD with Bartonella henselae, reported in 1992. In 1993, Dolan  isolated Rochalimae henselae (now called Bartonella henselae) from lymph nodes of patients with CSD. Bartonella spp. are commonly treated with antibiotics including azithromycin, based on a single small randomized clinical trial. Treatment may take up to one year to eliminate the disease. CSD often resolves spontaneously without treatment.
Serology and protein-based methods
IFA (immunofluorescence antibody assay) testing for the presence of antibodies in serum is used to diagnose B. henselae infection at the acute onset of Cat Scratch Disease symptoms, followed by PCR to confirm infecting species. IFA can generally be used to confirm a diagnosis of Bartonella infection, but is limited by antibody cross-reactivity with other bacteria species  which can cause a false positive, and antigen variability which can result in false negatives.Bartonella spp. often evade an immune response, thus antibodies may not be detected even concurrent with an infection, resulting in an IFA false negative rate of up to 83% in chronically infected patients when other test results (e.g. organism isolation or PCR) are positive. IFA sensitivity may range from 14 to 100%, causing discrepancies between PCR and serology test results. Positive IFA results do not distinguish between current infection and prior exposure.ELISA (enzyme-linked immunosorbent assay) is another method that has been used to detect Bartonella, but it has a low sensitivity (17-35%). Western blot for protein detection of Bartonella-associated proteins has also been reported, but this method does not show clear immunoreactive profiles. PCR
The CDC states that PCR testing from a single blood draw is not sufficiently sensitive for B. henselae testing, and can result in high false negative rates  due to a small sample volume and levels below the limit of molecular detection.Bartonella spp.