Bartonella bacilliformis
Encyclopedia
Bartonella bacilliformis is a proteobacterium
, Gram negative aerobic, pleomorphic, flagellated, motile, coccobacillary, 2–3 μm large and 0.2–0.5 μm wide and facultative intracellular bacterium.
in 1905, but it was not published until 1909. Barton originally identified them as endoglobular structures, which actually were the bacteria living inside red blood cells. Until 1993, the Bartonella genus
contained only one species; there are now more than 23 identified species, all of them within family Bartonellaceae.
, Ecuador
, and Colombia
. It is endemic
in some areas of Peru
,occurring outbreaks of the disease in new epidemic areas. The bacterium is transmitted by sandflies
of genus
Lutzomyia
.
The bacteria is inoculated by the sandflies bit to the capillaries where in a variable period of time (around 21 days) the bacteria produce a massive invasion of human red blood cells and a severe intravascular hemolytic anemia (acute phase of Carrion's disease). This phase is potentially a life-threatening infection and is associated with high fever
anemia, and transient immunosuppression. The acute phase typically lasts two to four weeks. Peripheral blood smears shows anisomacrocytosis with many coccobacilli adherent to red blood cells. Thrombocytopenia
is also seen and can be very severe. Neurologic involvement is sometimes seen (neurobartonellosis) and the prognosis
in this case is very guarded. The most feared complication is overwhelming infections by mainly enterobacterias such as Salmonella
, and also other parasites such as Toxoplasma gondii
or Pneumocystis.
It is known when the bacterium invade Endothelial cells, producing the chronic manifestation of the disease (Verruga Peruana). This phase consists of a benign
skin eruption with raised, reddish-purple nodules
(angiomatous tumours
). Visualization of the bacterium is possible using a silver stain
(the Warthin–Starry method) of biopsy.
or Peruvian wart (chronic phase of infection). The acute phase of the disease is a life threatening disease characterized by massive invasion of bartonella to human red blood cells and consequently an acute hemolysis and fever. If the infection is not treated the case fatality rate is 40 to 85% Patients in this phase of the infection can be complicated by overwhelming infections primarily by enterobacterias (Salmonella spp) and parasites (Toxoplasma gondii, Pneumocystis jirovecci).
The chronic phase is characterized by benign eruptive lesions that are pruritic and bleeding, and other symptoms like malaise and osteoarticular pain. Bartonella can be isolated from blood cultures and secretion of the lesions in people from endemic areas.
In the chronic phase, the treatment used traditionally has been streptomycin for 10 days. Since 1975, Rifampin has become the drug of choice for Verruga Peruana. However, failures of Rifampin treatment have also been reported and resistance can develop. Recently Macrolides has been used with similar effectivity.
Proteobacteria
The Proteobacteria are a major group of bacteria. They include a wide variety of pathogens, such as Escherichia, Salmonella, Vibrio, Helicobacter, and many other notable genera....
, Gram negative aerobic, pleomorphic, flagellated, motile, coccobacillary, 2–3 μm large and 0.2–0.5 μm wide and facultative intracellular bacterium.
History
The bacterium was discovered by the Peruvian microbiologist Alberto BartonAlberto Barton
Alberto Barton, was a Peruvian microbiologist who discovered the etiologic agent of Carrion´s disease or Oroya fever. The bacteria was named: Bartonella bacilliformis, in his honor.-Youth and education:...
in 1905, but it was not published until 1909. Barton originally identified them as endoglobular structures, which actually were the bacteria living inside red blood cells. Until 1993, the Bartonella genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
contained only one species; there are now more than 23 identified species, all of them within family Bartonellaceae.
Epidemiology
Bartonella bacilliformis is found only in PeruPeru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....
, Ecuador
Ecuador
Ecuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...
, and Colombia
Colombia
Colombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the...
. It is endemic
Endemic (epidemiology)
In epidemiology, an infection is said to be endemic in a population when that infection is maintained in the population without the need for external inputs. For example, chickenpox is endemic in the UK, but malaria is not...
in some areas of Peru
Peru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....
,occurring outbreaks of the disease in new epidemic areas. The bacterium is transmitted by sandflies
Sandfly
thumb|Sandfly biting a human's little fingerthumb|Sandfly biteSandfly is a colloquial name for any species or genus of flying, biting, blood-sucking Dipteran encountered in sandy areas...
of genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Lutzomyia
Lutzomyia
Lutzomyia is a genus of "sand flies" in the Psychodidae subfamily Phlebotominae and in the order Diptera. In the New World, Lutzomyia sand flies are responsible for the transmission of leishmaniasis, an important parasitic disease and Carrion's disease. Leishmaniasis is generally transmitted in...
.
Microbiology
For its isolation, special cultures are required containing complemental soy agar, proteases, peptones, some essential amino acids and blood. The optimum growing temperatures is 19–29°C. Colonies grow in Colombia blood agar supplemented 10% defibrinated bovine blood incubated at 19–25°C for 2 weeks.Pathophysiology
Fever
Fever is a common medical sign characterized by an elevation of temperature above the normal range of due to an increase in the body temperature regulatory set-point. This increase in set-point triggers increased muscle tone and shivering.As a person's temperature increases, there is, in...
anemia, and transient immunosuppression. The acute phase typically lasts two to four weeks. Peripheral blood smears shows anisomacrocytosis with many coccobacilli adherent to red blood cells. Thrombocytopenia
Thrombocytopenia
Thrombocytopenia is a relative decrease of platelets in blood.A normal human platelet count ranges from 150,000 to 450,000 platelets per microliter of blood. These limits are determined by the 2.5th lower and upper percentile, so values outside this range do not necessarily indicate disease...
is also seen and can be very severe. Neurologic involvement is sometimes seen (neurobartonellosis) and the prognosis
Prognosis
Prognosis is a medical term to describe the likely outcome of an illness.When applied to large statistical populations, prognostic estimates can be very accurate: for example the statement "45% of patients with severe septic shock will die within 28 days" can be made with some confidence, because...
in this case is very guarded. The most feared complication is overwhelming infections by mainly enterobacterias such as Salmonella
Salmonella
Salmonella is a genus of rod-shaped, Gram-negative, non-spore-forming, predominantly motile enterobacteria with diameters around 0.7 to 1.5 µm, lengths from 2 to 5 µm, and flagella which grade in all directions . They are chemoorganotrophs, obtaining their energy from oxidation and reduction...
, and also other parasites such as Toxoplasma gondii
Toxoplasma gondii
Toxoplasma gondii is a species of parasitic protozoa in the genus Toxoplasma. The definitive host of T. gondii is the cat, but the parasite can be carried by many warm-blooded animals . Toxoplasmosis, the disease of which T...
or Pneumocystis.
It is known when the bacterium invade Endothelial cells, producing the chronic manifestation of the disease (Verruga Peruana). This phase consists of a benign
Benign
A benign tumor is a tumor that lacks the ability to metastasize. Common examples of benign tumors include moles and uterine fibroids.The term "benign" implies a mild and nonprogressive disease. Indeed, many kinds of benign tumors are harmless to human health...
skin eruption with raised, reddish-purple nodules
Nodule (medicine)
For use of the term nodule in dermatology, see Nodule In medicine, a nodule refers to a relatively hard, roughly spherical abnormal structure....
(angiomatous tumours
Angioma
Angiomas are benign tumors derived from cells of the vascular or lymphatic vessel walls or derived from cells of the tissues surrounding these vessels....
). Visualization of the bacterium is possible using a silver stain
Silver stain
Silver staining is the use of silver to selectively alter the appearance of the target.-Use in medicine:It is used to stain histologic sections. This kind of staining is important especially to show proteins and DNA. It is used to show both substances inside and outside cells...
(the Warthin–Starry method) of biopsy.
Disease
Bartonella bacilliformis is the etiologic agent of Carrion´s disease or Oroya fever (acute phase of infection) and Verruga peruanaVerruga peruana
Verruga peruana is the chronic delayed stage of infection by Bartonella bacilliformis....
or Peruvian wart (chronic phase of infection). The acute phase of the disease is a life threatening disease characterized by massive invasion of bartonella to human red blood cells and consequently an acute hemolysis and fever. If the infection is not treated the case fatality rate is 40 to 85% Patients in this phase of the infection can be complicated by overwhelming infections primarily by enterobacterias (Salmonella spp) and parasites (Toxoplasma gondii, Pneumocystis jirovecci).
The chronic phase is characterized by benign eruptive lesions that are pruritic and bleeding, and other symptoms like malaise and osteoarticular pain. Bartonella can be isolated from blood cultures and secretion of the lesions in people from endemic areas.
Treatment
Before the antibiotic era, the only treatment for the acute phase was blood tansfusion, but the effectiveness of this treatment was poor and the mortality rate was high. Later, with the discovering of new antibiotics, Penicillin, chloramphenicol, tetracycline, and erythromycin have been used successfully. However, because of the risk of overwhelming infections by enterobacteria, quinolones are preferred. Therapeutic failures and persistent bacteremia have been reported with chloramphenicol, and successful treatment with this drug does not appear to eliminate the patient's risk for development of the eruptive phase. So, the drug of choice is Ciprofloxacin.In the chronic phase, the treatment used traditionally has been streptomycin for 10 days. Since 1975, Rifampin has become the drug of choice for Verruga Peruana. However, failures of Rifampin treatment have also been reported and resistance can develop. Recently Macrolides has been used with similar effectivity.