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From Cat Scratch Disease to Bartonellosis

Bartonellosis is a term used to encompass all infections caused by pathogenic Bartonella

species. Bartonella are emerging, flea-borne bacteria that are highly adapted to living in

mammalian hosts and are implicated in a wide spectrum of diseases in humans and

animals.

Edit

Bartonella

species Primary Reservoir Vector Accidental Host(s) and

[human disease]

Bartonella

alsatica

Rabbit

(Oryctolagus cuniculus)

Rabbit flea?

(Spilopsyllus

cuniculi)

Human

[endocarditis]

Bartonella

bacilliformis

Human Sandfly

(Lutzomia

verrucarum)

None

[Carrion's disease, Oroya

fever, verruga peruana]

Bartonella

clarridgeiae

Cat

(Felis catus)

Cat flea

(Ctenocephalides

felis)

Human, dog

[cat scratch disease,

endocarditis]

Bartonella

elizabethae

Rat

(Rattus norvegicus)

Oriental rat flea

(Xenopsylla

cheopis)

Human, dog

[endocarditis, neuroretinitis]

Bartonella

grahamii

Wild mice

(agrestris, Apodemus,

Clethrionomys glareolus, Microtus

flavicollis)

Rodent fleas Human

[neuroretinitis]

Bartonella

henselae

Cat

(felis catus)

Cat flea

(Ctenocephalides

felis)

Human, dog, horse, marine

animals

[Cat scratch disease,

bacillary angiomatosis,

endocarditis, neuroretinitis,

bacteraemia]

Bartonella

koehlerae

Cat

(Felis catus)

Cat flea

(Ctenocephalides

felis)

Human, dog

[endocarditis]

Bartonella

melophagi

Sheep

(Ovis aries)

Sheep ked

(Melophagus

ovinus)

Human

[pericarditis, chronic fatigue]

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Bartonella

quintana

Human Body louse

(Pediculus

humanis)

Cat, dog

[endocarditis, trench fever,

bacillary angiomatosis]

Bartonella

rochalimae

Canids Fleas?

(Pulex irritans,

Pulex stimulans)

Human, dog

[bacteraemia, fever]

Bartonella

tamiae

Unknown

(Rat?)

Mites? Ticks? Human

[bacteraemia, fever]

Bartonella

vinsonii

arupensis

White-footed mouse

(Peromyscus leucopus)

Unknown

(Fleas? Ticks?)

Human

[bacteraemia, fever,

endocarditis]

Bartonella

vinsonii

berkhoffii

Coyote

(Canis latrans)

Dog

(Canis familiaris)

Unknown

(Ticks?)

Human, cat [endocarditis]

Bartonella

washoensis

Californian ground squirrel

(Spermophilus beecheyii)

Fleas

(Oropsylla

montana)

Human, dog

[myocarditis, endocarditis]

Adapted from: Edward Bealmear Breitschwerdt; Bartonellosis: One Health Perspectives for an Emerging

Infectious Disease, ILAR Journal, Volume 55, Issue 1, 1 January 2014, Pages 46–58,

https://doi.org/10.1093/ilar/ilu015

As a genus, these bacteria cycle from the blood to tissues around the body making them

difficult to detect and identify. There were only 2 named Bartonella species prior 1990, but

now there are about 20 species associated with human disease. Bartonella henselae, the

causative agent of Cat Scratch Disease (CSD), is the most common species found in both

animals and humans in the United States. Although the first case was described in the

1950s, B. henselae was not identified until extensive research on HIV patients was

performed in the 1990s.

Bartonellosis was originally thought to primarily affect immunocompromised individuals

because a normal immune system could self-regulate the infection. However, recent

research has suggested that immunocompetent people can be chronically infected, but be

asymptomatic or show atypical symptoms. Furthermore, these chronic infections can lead

to cardiac and neurologic complications that are life threatening. Read on to learn more

about symptoms, risk factors, and the testing options that Galaxy Diagnostics offers for

Bartonella.

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Acute vs. Chronic Bartonellosis

Research on Bartonella species has increasingly suggested its role in chronic diseases

ranging from neurovascular to rheumatologic.

Despite these findings, reported cases are often focused on acute infections, such as CSD,

Trench Fever, and Carrion’s disease, that show typical clinical signs making them easier to

diagnose. Acute infections are likely to be diagnosed and treated quickly, but the story is

different for chronically ill patients that are atypical or asymptomatic.

Chronically ill patients may show non-specific symptoms, like headaches, malaise, or

fatigue, in the beginning of the infection. As the Bartonella species causes inflammation in

different tissues around the body, symptoms can resolve and relapse in a cyclic pattern.

Furthermore, co-infections have been been documented with other bacteria (Borrelia

burgdorferi, Anaplasma, etc.) and parasites (Babesia microti, Theileria) which complicates

clinical diagnosis of chronic bartonellosis even more. Unfortunately, these chronic

infections are often mistaken for other disorders, such as immune-mediated diseases