by In a previous post we discussed the relatively short history of scientific recognition of Bartonella species infections (bartonellosis).
Chronic Bartonella infection in the United States was only recognized at the end of the 20th century as symptoms began to be seen more frequently in HIV patients. Furthermore, symptoms tended to be more serious in these patients due to their compromised immune systems (“immunocompromised”). Among the symptoms these patients frequently developed were bacillary angiomatosis, caused by Bartonella henselae or Bartonella quintana, and bacillary peliosis, caused by Bartonella henselae.
“Bacillary” means rod shaped, that is, it was recognized that these conditions were caused by bacteria that were shaped like rods. “Angiomatosis” describes a condition in which proliferating capillaries develop in a lobular pattern. It is seen in the skin or just under the skin (“subdermal”), in bones, and in other organs. “Peliosis” describes a condition in which the vascular system develops blood-filled cavities, usually in the liver but also in other organs.
Although these conditions are observed more frequently in immunocompromised individuals, seemingly healthy people can develop these conditions as well. The prevalence and full implications of Bartonella species infections in healthy populations are not well understood at this point.
Some individuals with Bartonella infections may be unaware and asymptomatic, while others face debilitating non-specific symptoms. Even in patients who have bacillary angiomatosis or bacillary peliosis, it can still be difficult to find evidence of Bartonella species infection.
Bacillary angiomatosis may look different in people with darker skin than in people with lighter skin. People with dark skin are more likely to get a plaque form of the condition that causes raised dark areas on the skin. Other forms can appear as papules that can vary in size and color, nodules, or masses. Lesions in the bones and organs are obviously harder to diagnose than lesions on the skin and can cause a wide variety of symptoms from jaundice to psychiatric symptoms.
These conditions are diagnosed by taking samples of the lesions and looking at their structure under a microscope (histology). Histology is especially useful for differentiating bacillary angiomatosis from Kaposi’s sarcoma, another condition seen in immunocompromised people. Kaposi’s sarcoma is caused by human herpesvirus 8 (HHV8), a virus in the same family as Epstein-Barr virus (EBV). Under a microscope, the structure of a Kaposi’s sarcoma lesion is different from that of a bacillary angiomatosis lesion.
Bacillary peliosis is also diagnosed by taking a sample, but peliosis can be caused by a variety of infections, cancers, and medications. Peliosis occurs in up to 20% of patients with a kidney transplant. It is more difficult to determine if the cause of peliosis is Bartonella henselae infection.
Serology (looking for an immune response to Bartonella antigens) and PCR (looking for Bartonella DNA) testing are also used to diagnose these conditions. At Galaxy Diagnostics, we offer Bartonella ePCR testing for blood and/or tissue samples to maximize the chances of finding Bartonella DNA when bartonellosis is suspected.
In reviewing these references, note that the cause of these infections was still uncertain even into the 1990s. The references are a historical record showing how recently understanding of Bartonella species infections has developed:
Garcia-Tsao, G. et al. (1992). Bacillary peliosis hepatis as a cause of acute anemia in a patient with the acquired immunodeficiency syndrome. Gastroenterology, 102, 1065-1070. https://www.gastrojournal.org/article/0016-5085(92)90200-I/pdf
Guerra, L. G. et al. (1993). Rapid response of AIDS-related bacillary angiomatosis to azithromycin. Clinical Infectious Diseases, 17, 264-266. https://www.jstor.org/stable/4457278?seq=1#page_scan_tab_contents
Izumi, S. et al. (1994). Laparoscopic study of peliosis hepatis and nodular transformation of the liver before and after renal transplantation: Natural history and aetiology in follow-up cases. Journal of Hepatology, 20(1), 129-137. doi:10.1016/S0168-8278(05)80479-9
Koehler, J. E. (1997). HIV and Bartonella: Bacillary angiomatosis and peliosis. San Franciso: University of California, San Francisco. http://hivinsite.ucsf.edu/InSite?page=kb-05-01-03
Mateen F. J. et al. (2005). Bacillary angiomatosis in an HIV-positive man with multiple risk factors: A clinical and epidemiological puzzle. Canadian Journal of Infectious Diseases and Medical Microbiology, 16(4), 249-252. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2095030/
Nikam, B. P. et al. (2018). Bacillary angiomatosis in an immunocompetent individual. Indian Dermatology Online Journal, 9(3), 205-206. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5956875/
Perkocha, L. A. et al. (1990). Clinical and pathological features of bacillary peliosis hepatis in association with Human Immunodeficiency Virus infection. The New England Journal of Medicine, 323, 1581-1586. https://www.nejm.org/doi/full/10.1056/NEJM199012063232302
Stoler, M. H. et al. (1983). An atypical subcutaneous infection associated with Acquired Immune Deficiency Syndrome. American Journal of Clinical Pathology, 80(5), 714-718. https://www.ncbi.nlm.nih.gov/pubmed/6637883