Bartonellosis is a group of infectious diseases caused by bacteria called Bartonella. These bacteria can affect various parts of the body and lead to a range of symptoms.
Bartonellosis is a group of emerging infectious diseases caused by bacteria belonging to the Bartonella genus. Bartonella includes at least 22 named species of bacteria that are mainly transmitted by carriers (vectors), including fleas, lice, or sandflies. Both domestic and wild animals can be infected with Bartonella species (Bartonella spp) by these vectors. Among the Bartonella spp, at least 14 have been implicated in diseases that can be transmitted from animals to people (zoonotic disease). Of these zoonotic species, several may be transmitted to humans by companion animals (dogs and cats), typically through a bite or scratch.
Human diseases that have been identified to be caused by one of the Bartonella spp bacteria include cat scratch disease (Bartonella henselae), Carrion’s disease (Bartonella bacilliformis), and trench fever (Bartonella quintana). Bartonella spp have also been associated with diseases of the skin (bacillary angiomatosis), liver (peliosis hepatis), heart (endocarditis), eyes (neuroretinis), blood (bacteremia), and brain (encephalitis). Bartonella infection does not always cause overt illness. A number of studies have detected clinically healthy people that have tested positive (seropositive) for Bartonella but have no known history of typical Bartonella symptoms. Those who do become ill usually develop mild disease that tends to end without treatment (self-limiting). However, Bartonella can cause severe infection in some people. Immunocompromised patients, such as those undergoing immunosuppressive treatments for cancer, organ transplant patients, and people with HIV/AIDS, are more likely to develop severe, life-threatening disease.
In 1909, Dr. Alberto Barton discovered the organism that became named Bartonella bacilliformis. Diseases caused by Bartonella spp occur all over the United States and in all major regions of the world, with higher prevalence occurring in areas that harbor insect carriers (arthropod vectors).
Types of Bartonellosis (5 Types)
- Cat Scratch Disease (CSD): This is the most common type of Bartonellosis. It occurs when you get scratched or bitten by an infected cat. Symptoms include fever, swollen lymph nodes, and a sore at the site of the scratch or bite.
- Trench Fever: Often seen in soldiers during wars, trench fever is transmitted by body lice. It causes high fever, joint pain, and severe headaches.
- Bartonella Endocarditis: This is a rare and serious infection of the heart valves. It can occur in people with existing heart problems and may lead to heart valve damage.
- Bacillary Angiomatosis: People with weakened immune systems, like those with HIV/AIDS, are at risk for this form of Bartonellosis. It causes skin lesions that may look like tumors.
- Oroya Fever: Found mainly in South America, this type causes fever and severe anemia. It’s usually transmitted through sandfly bites.
Causes of Bartonellosis
- Bartonella Bacteria: The primary cause of Bartonellosis is infection with various species of Bartonella bacteria. These bacteria are typically transmitted through bites from infected insects, like fleas, sandflies, or ticks.
- Cat Scratches and Bites: Cat Scratch Disease occurs when Bartonella bacteria from a cat’s claws or mouth enter a person’s body through a scratch or bite.
- Lice Infestation: Trench Fever is spread by body lice that carry Bartonella bacteria. Close contact with infected individuals or their belongings can lead to transmission.
- Immune System Weakness: People with compromised immune systems, such as those with HIV/AIDS, are more susceptible to certain types of Bartonellosis like Bacillary Angiomatosis.
- Geographic Factors: Some forms of Bartonellosis, like Oroya Fever, are more prevalent in specific geographic regions, such as South America.
Cat scratch disease:
Cat scratch disease is caused by the B. henselae bacterium. Most cases follow a lick, scratch, or bite from a cat or kitten when the bacterium is present on the cat’s claws or oral cavity. Fleas transmit the bacteria between cats. Some case reports have suggested transmission may occur from cat fleas directly to humans, but this has not yet been proven. Cat-to-cat and person-to-person transmission has not been documented. There have also been reports of the disease following the scratch or bite of dogs in 5% of cases.
A feline infected with B. henselae is a common occurrence. Up to half of domestic cats have antibodies to B. henselae, which indicates that they have been previously exposed to these bacteria. Because cats are infected with B. henselae by fleas, preventing flea exposure will reduce B. henselae infection in cats and kittens and thereby prevent human infection. Kittens under 12 months of age are much more likely to transmit the disease than adult cats. Outdoor cats and cats infested with fleas are also more likely to show antibodies (test seropositive) to B. henselae. Animals that are carrying the disease are not ill, and will not exhibit any symptoms. Not every person exposed to the carrier animal will develop cat scratch disease, and in most cases the symptoms are temporary (transient) and mild.
Carrion’s disease:
B. bacilliformis is the etiologic agent of Carrion’s disease or Oroya fever (acute phase of infection) and verruga peruana or Peruvian warts (chronic phase of infection). The bacterium is primarily carried and transmitted by the night-biting sand fly known as Lutzomyia (formerly Phlebotomus).
The B. bacilliformis bacterium enters the bloodstream via the bite of the sand fly, enabling the bacterium to attach to the surface of erythrocytes. Bacterial invasion and reproduction leads to abnormal fragility and premature destruction of many erythrocytes in the bloodstream (hemolysis). This results in abnormally decreased red blood cell levels and reduced concentrations of hemoglobin, the oxygen-carrying component of the blood (hemolytic anemia). In addition, the bacterium may invade cells lining small blood vessels (capillary endothelial cells), potentially leading to blockage of normal blood flow (vascular occlusion). Severe hemolytic anemia and the abnormal formation of blood clots within small blood vessels may potentially lead to life-threatening complications without prompt appropriate treatment.
With developing immunity, levels of the bacterium markedly decrease in the blood. However, without appropriate antibiotic therapy, asymptomatic low-grade bacteremia may persist for months or years in some cases.
Following the symptom-free (latent) period, most untreated individuals develop the distinctive skin lesions characteristic of verruga peruana. The nodular lesions consist of newly formed blood vessels (neovascular proliferation) infiltrated by certain white blood cells that play an important role in fighting and destroying invading microorganisms (e.g., lymphocytes, macrophages).
Trench fever:
Trench fever is caused by infection with B. quintana most likely transmitted by the human body louse (Pediculus humanus) and is commonly found in homeless, alcoholic, and poverty-stricken populations where poor sanitation and poor hygiene often occurs. Other diseases that have been identified to be caused by B. quintana include bacillary angiomatosis (angioproliferative lesions), bacteremia, and endocarditis. Human endocarditis has now been associated with at least nine different Bartonella spp.
Bartonella vinsonii subsp. berkhoffii has been isolated from immunocompetent patients with endocarditis, arthritis, neurological disease and vasoproliferative neoplasia. Dogs and wild canines (foxes, coyotes, wolves), which are the primary reservoir hosts, are the suspected reservoir hosts for this bacterium, and ticks are the suspected vectors, but this has not been scientifically proven.
Symptoms of Bartonellosis
- Fever: Fever is a common symptom in all types of Bartonellosis. It can range from mild to high.
- Swollen Lymph Nodes: Your lymph nodes may become enlarged, especially near the site of a scratch or bite in Cat Scratch Disease.
- Skin Lesions: Bacillary Angiomatosis can cause raised, red or purple skin lesions that may resemble tumors.
- Joint Pain: Trench Fever often leads to severe joint pain, making movement uncomfortable.
- Anemia: Oroya Fever is characterized by a drop in red blood cells, leading to anemia and fatigue.
Diagnostic Tests for Bartonellosis
- Blood Tests: A blood test can detect Bartonella antibodies or DNA in your blood, confirming the infection.
- Biopsy: In some cases, a tissue sample from a skin lesion or affected organ may be examined under a microscope to identify Bartonella bacteria.
- PCR Test: Polymerase Chain Reaction (PCR) tests can directly detect Bartonella DNA in blood, tissue, or other samples.
- Imaging: X-rays, CT scans, or echocardiograms may be used to assess the extent of organ involvement, especially in Bartonella Endocarditis.
- Serology: This blood test measures antibody levels to Bartonella and can help determine if you’ve been exposed to the bacteria.
Treatments for Bartonellosis
- Antibiotics: The most common treatment for Bartonellosis is a course of antibiotics prescribed by your healthcare provider. Antibiotics like azithromycin or doxycycline are often effective.
- Supportive Care: Rest, fluids, and over-the-counter pain relievers can help manage symptoms like fever and joint pain.
- Heart Valve Surgery: In severe cases of Bartonella Endocarditis, surgery may be necessary to repair or replace damaged heart valves.
- Immune Support: People with weakened immune systems may require additional treatments to boost their immune response.
- Vector Control: Preventing insect bites by using repellents and avoiding areas with infected insects can reduce the risk of Bartonellosis.
Antibiotics may be considered for severe or systemic disease. Faster reduction of lymph node size has been demonstrated with a 5-day course of azithromycin. Other antibiotics that have been considered effective include rifampin, ciprofloxacin, gentamicin, and trimethoprim/sulfamethoxazole. Bartonella henselae is generally resistant to penicillin, amoxicillin, and nafcillin. Doxycycline and rifampin in combination are the preferred medications for treating neuroretinitis. Effective antibiotic therapy for the complication of endocarditis should include an aminoglycoside prescribed for a minimum of 2 weeks followed by doxycycline or ceftriaxone for 6 weeks.
The treatment of choice for Oroya fever is administration of the antibiotic chloramphenicol (due to frequent, intercurrent infection with Salmonella). Ciprofloxacin has also been recommended. Antibiotic therapy may rapidly treat acute febrile illness associated with Oroya fever. Blood transfusions may be required to treat severe anemia. For antibiotic treatment of verruga peruana, rifampin and streptomycin are typically recommended. Other treatment for this disorder is symptomatic and supportive.
Carrion’s disease may be prevented by avoiding the sandflies that transmit the bacterium to humans. Insect repellents, bed nets, and long-acting insecticides can help prevent exposure to these insects.
Tetracycline-group antibiotics (doxycycline, tetracycline) are commonly used to treat trench fever. Uncomplicated disease responds to doxycycline and gentamicin. Chloramphenicol is an alternative medication recommended when tetracycline usage is undesirable, such as in severe liver malfunction, kidney deficiency, in children under nine years and pregnant women. Macrolides and ceftriaxone have also been effective.
A longer duration of treatment is recommended for immunocompromised patients and when the liver or other organs are involved. In patients with AIDS and bacillary angiomatosis, the primary choices of antibiotics are erythromycin or doxycycline. Doxycycline combined with rifampin is effective in patients with severe disease. An extended treatment if often required in these cases.
Though the course of the disease can be far more severe and potentially life-threatening for immunocompromised patients, these patients typically experience full resolution of disease with appropriate antibiotic use and management of complications. The response of immunocompromised patients to antibiotics is significantly more dramatic than immunocompetent patients. Some researchers believe that less virulent strains tend to infect immunocompromised patients and are perhaps more antibiotic responsive.
Drugs Used in Bartonellosis Treatment
- Doxycycline: This antibiotic is commonly used to treat Bartonellosis, especially Cat Scratch Disease.
- Azithromycin: Another antibiotic that can be effective in treating various forms of Bartonellosis.
- Ceftriaxone: In severe cases, intravenous (IV) antibiotics like ceftriaxone may be necessary.
- Pain Relievers: Over-the-counter pain relievers like acetaminophen or ibuprofen can help alleviate fever and pain.
- Immunosuppressive Drugs: In some cases, individuals with immune system-related Bartonellosis may require immunosuppressive medications to manage their condition.
In conclusion, Bartonellosis is a group of infections caused by Bartonella bacteria. It can lead to a variety of symptoms, and the treatment mainly involves antibiotics. If you suspect you have Bartonellosis or experience any of the mentioned symptoms, it’s essential to consult a healthcare professional for proper diagnosis and treatment. Additionally, taking precautions to avoid insect bites, especially in endemic areas, can help prevent Bartonellosis.
Disclaimer: Each person’s journey is unique, treatment plan, life style, food habit, hormonal condition, immune system, chronic disease condition, previous medical history is also unique. So always seek the best advice from a qualified medical professional or health care provider before trying any treatments to ensure to find out the best plan for you. This guide is for general information and educational purposes only. If you or someone are suffering from this disease condition bookmark this website or share with someone who might find it useful! Boost your knowledge and stay ahead in your health journey. Thank you for giving your valuable time to read the article.
