Bartonellosis
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Bacterial infection
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Many possible symptoms
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May resemble other diseases
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Unreliable tests
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Often inappropriate treatments
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Can become chronic
Sections of the page:
THE INFECTION
What is bartonellosis?
Bartonellosis is an infectious disease caused by bacteria of the Bartonella genus. Historically, it has been classified into several distinct diseases according to symptoms and the Bartonella species involved [1].
The three best-known are :
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Cat scratch disease, caused by Bartonella henselae
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Trench fever, caused by Bartonella quintana
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Carrion's disease, caused by Bartonella bacilliformis
To date, over 36 different species of Bartonella have been discovered. Around half of these can cause human disease, with similar symptoms [2]. Consequently, this classification (one disease per species) is now losing its meaning, and the simple term bartonellosis seems more appropriate for naming these diseases.
In addition, it has been shown that several species can coexist in a patient (such as B. henselae and B. vinsonii), which can lead to a worsening of symptoms and increase the risk of developing more severe disease [17].
Like Lyme borreliosis and babesiosis, bartonellosis can be difficult to diagnose and extremely disabling, sometimes leading to severe neurological and psychiatric symptoms [1-3].
A common infection :
Bartonella is one of many infectious pathogens frequently present in association in patients, alongside other agents such as Borrelia and Babesia [4-5-6]. When other pathogens are present in addition to Bartonella, it is referred to as "co-infections" "co-infected persons". Often, it is the combination of these pathogens in the same individual, coupled with a complex immune response to their simultaneous presence, that leads to severe and disabling chronic symptoms [7-8].
How are they transmitted ?
Bartonella species are transmitted in a variety of ways by many animals:
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mammals: cats, dogs, rabbits, etc.
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insects: fleas, bedbugs, body lice, horseflies, blood-sucking flies, etc.
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arachnids: ticks, spiders, etc.
Mammals transmit these bacteria to humans by scratching, biting or licking an open wound. In the case of many insects and arachnids, transmission occurs through bites or indirect contamination via their excrement [2-9-10].
The many pathogenic Bartonella species (over 20) have reservoirs and vectors that vary according to their species. The table below gives a brief summary for a few species:
B. henselae
Cats, humans, dogs, horses
Fleas, lice, cats (scratches), ticks
B. quintana
Humans, cats, dogs
Body lice, fleas, bedbugs
B. bacilliformis
Humans
Sand flies, fleas
B. elizabethae
Rats, dogs, humans
Chips
B. vinsonii ssp. berkhoffi
Dogs, horses, humans
Fleas, bites (dogs), ticks,
B. clarridgeiae
Cats, dogs
Bites, scratches, fleas, ticks
B. alsatica
Rabbits, humans
Scratches, fleas, ticks
B. rochalimae
Dogs, humans
Fleas, ticks
B. koehlerae
Cats, dogs, humans
Chips
B. grahamii
Mice, humans
Chips
B. washoensis
Squirrels
Fleas, ticks
+ 12 other species
...
...
Reservoir
Vectors
Species
What is the prevalence in Switzerland ?
Although Bartonella infections are common, there are as yet no studies on prevalence in humans. However, published studies have shown that between 8% and 12% of cats in Switzerland are infected with Bartonella henselae, and an average of 15.3% of cats and 3.6% of dogs worldwide [11-12].
In Switzerland, some 1.8 million cats and 500,000 dogs live alongside humans, making them a major potential source of Bartonella contamination.
Finally, up to 40% of ticks in Europe carry Bartonella henselae [13].
Bartonellosis
Bacterial infection
Many possible symptoms
May resemble other diseases
Unreliable tests
Often inappropriate treatments
Can become chronic