| Bartonella henselae | |
|---|---|
 | |
Scientific classification | |
| Domain: | Bacteria |
| Kingdom: | Pseudomonadati |
| Phylum: | Pseudomonadota |
| Class: | Alphaproteobacteria |
| Order: | Hyphomicrobiales |
| Family: | Bartonellaceae |
| Genus: | Bartonella |
| Species: | B. henselae |
| Binomial name | |
| Bartonella henselae (Regneryet al. 1992) Brenneret al. 1993 | |
| Synonyms | |
Rochalimæa henselaeRegneryet al. 1992 | |
Bartonella henselae, formerlyRochalimæa henselae, is abacterium that is the causative agent ofcat-scratch disease[1] (bartonellosis). It primarily infectsred blood cells andendothelial cells and is transmitted to humans through scratches, bites, orflea vectors associated with domestic and feral cats.[2]
Bartonella henselae is a member of the genusBartonella, one of the most common types of bacteria in the world.[specify] It is a facultativeintracellular microbe that targets red blood cells. In the United States, about 20,000 cases are diagnosed each year,[citation needed] most under 15 years old. Most often, it is transmitted by scratches or bites from kittens.[3] Higher prevalence is reported in warm, humid climates where flea infestations are more common.
The specific namehenselae honors Diane Marie Hensel (b. 1953), a clinical microbiology technologist at University of Oklahoma Health Sciences Center, who collected numerous strains and samples of the infective agent during an outbreak in Oklahoma in 1985.[4]
Bartonella henselae is a Gram-negative, rod-shaped bacterium that invades endothelial and red blood cells. One study showedBartonella henselae invaded the mature blood cells of humans.[5] It infects the host cell by sticking to it usingtrimeric autotransporter adhesins.[6]
Bartonella henselae is aGram-negativerod.[6][7] It can be cultured in a lysis-centrifugation blood culture.[8] The presence of bacteria can be detected byWarthin-Starry stain, or by a similarsilver stain technique performed on infected tissue. A pan-Bartonella PCR detection is non-invasive and uses blood or biopsies to diagnose.[9]
Bartonella henselae infection can appear up to 10 days after exposure to the microbe. Symptoms start with a papule at the site the microbe entered, followed bylymphadenopathy, usually in the axillary node. Half of patients also get aches, nausea, abdominal pain, and malaise.[10] Many other complications can arise from this infection beyond the typical fever, lymphadenopathy, and general malaise. Immunocompromised people or patients who already have other conditions are at greater risk for further complications. Some cases have been found in children who had previous heart-valve disease; these children gotendocarditis fromB. henselae infection. Some patients had hepatosplenic involvement, myalgia, and arthritis after exposure toB. henselae.[10] In rare cases,osteomyelitis, an infection in the bone, can be a manifestation ofB. henselae.[11]
No definite treatment regimen is known for a patient infected withB. henselae. Treatment depends on the wide range of symptoms that present. In most cases, it will resolve on its own in four to six weeks.[12]Aminoglycosides in laboratory tests showed some bactericidal activity.Bacteriostatic antibiotics are not able to easily get through to intracellularBartonella, so they are not recommended. Inimmunocompromised patients, pain medication is often prescribed. Nodes may need to be aspirated if painful, microabscesses often form, the abscess needs to be aspirated in many places to remove all the exudate. Because of chronicsinus tract formation risks, the nodes should not be incised to be drained.Azithromycin can be used for lymphadenopathy, which is enlarged or swollen lymph nodes.[10]
Regular flea control measures, such as using flea preventatives on cats, are essential to reduce the risk ofBartonella henselae transmission. Practicing proper hygiene, including washing hands after handling cats and avoiding rough play with kittens, can further minimize exposure. Additionally, immunocompromised individuals should take extra precautions by limiting contact with young cats and avoiding direct exposure to cat saliva.[13]