What is Bartonellosis & How is it Treated?|Types, Epidemiology, Diagnosis of Bartonellosis

Bartonellosis is an infectious disease that is caused due to a bacteria belonging to the Bartonella group. This group of bacteria holds a minimum of 22 species of bacteria that have been named so far. These bacteria are transmitted through the medium of vectors or carriers. Common carriers, in this case, will be lice, fleas and sand flies. Wild animals as well as domestic animals can be infected with these bacteria. Humans can contract Bartonellosis through animals. Cases of humans being infected by their pet dogs and cats are also common. These infections can typically happen from bites or scratches.

What is Bartonellosis & How is it Treated?

Bartonellosis in Humans

Bartonellosis seen in humans is generally activated by the Bartonella species bacteria. These bacteria can result in cat scratch disease, trench fever, and Carrion’s disease.(1) The Bartonella species bacteria can also lead to other skin diseases as well. Other problems that can occur are liver problems of peliosishepatis; endocarditis, a condition of the heart; bacteremia, a condition of the blood; the neuroretinal problem of the eyes and in certain cases, it can also affect the brain. However, Bartonella is a condition that always does not make a person sick. Often an adult who has been traced with this problem has led a completely healthy life. Even if some mild sickness is developed, it gets cured on its own after a certain period of time. People having a weak immune system due to cancer treatment or are infected with HIV/AIDS can develop life-threatening conditions due to Bartonellosis.

The disease was first discovered and explained by Dr. Alberto Barton in the year 1909. This is one of the most common diseases that are found in several parts of the US and also other major regions of the world. The main prevalence of this disease is found to be through arthropod vectors.(1)

Types of Bartonellosis

The sub-types of Bartonellosis include:

Cat Scratch Disease

Cat Scratch Disease is a disease that happens mainly due to Bartonellahenselae. It leads to enlargement of the lymph nodes that affect the axilla, neck and the groin. This condition can continue for a period of two to three months. The area of skin that was scratched by the cat can also develop a red-brown skin papule. However, this papule can also develop at a later stage. The lymph node that is enlarged is usually tender and quite painful. Some of the patients can also remain asymptomatic or even afebrile.

Children, when infected with Bartonellosis, can develop a fever. These bacteria can present other problems like bacillary angiomatosis and even peliosis hepatis. These conditions become acute in people with low immunity such as HIV patients. Some of the common symptoms of Bartonellosis due to cat scratch are a headache, high fever, disorientation, loss of memory, loss of coordination and loss of sleep. The bacteria attacks the immune system of a person and block the pathway of Nf-kB apoptosis. The spread of the disease can be aggressive if the person is infected with other forms of bacteria simultaneously.(1)

Bacillary Angiomatosis

This is a disease that is also caused by B.henselae and B.quintana bacteria. Bacillary Angiomatosis is a vascular proliferative disease that affects human skin and also other organs. The disease was seen to be prevalent in patients with a compromised immune system, such as the patients of HIV/AIDS or patients who have undergone some organ transplant surgery. The condition can affect the lymph nodes and also the spleen, liver, and the bone marrow.

Peliosis Hepatis

Peliosishepatis is known to cause by B. henselae. In this condition, a vascular proliferation occurs in the sinusoid of hepatic capillaries that fill up certain parts of the liver with blood. This is a condition that is rather common for HIV patients and patients who have undergone organ transplant surgeries.(1) This condition can also be related to problems of the spleen and even the condition of bacillary angiomatosis occurring in the skin.

Trench Fever

Trench fever is also known as quintan fever or five-day fever. It happens as an initial manifestation of the infection of B.quintana. Symptoms can differ from patient to patient where some can be asymptomatic and others can develop serious ailments. In many cases, an acute fever sets in with a severe headache and also a feeling of dizziness and shin pain. This is a condition that is found to be rather common amongst soldiers and also people without a definite home.

Epidemiology of Bartonellosis

As already mentioned, people who have a compromised immune system are the ones who are more susceptible to develop Bartonellosis. Those who own a cat do not always develop a cat scratch disease. Let’s say about 1% of them develops the problems and that too not all of them undergoes very serious conditions. The male owners are at a higher risk than the female owners.

When talking about carrion’s disease, it was earlier restricted to the geographic region of the Andes Mountains in South America. It has been transmitted to the other parts of the world gradually through the medium of travelers.(1)

Traces of the Trench Fever were found as early as World War I. It was a really common ailment amongst the soldiers. The outbreak often happens to be quite regional although the exact reason for this phenomenon is not understood. In many cases, the patient remains asymptomatic.

Diagnosis of Bartonellosis

From the early times, the process of serology has been used along with the technique of polymerase chain reaction so that the condition of Bartonella can be diagnosed. However, false and faulty results have also been quite high in this context. In order to overcome these problems, new researches have been done with regards to the diagnosis and the treatment, and the medical fraternity has come up with a new way of finding and diagnosing the condition. This is the use of the Bartonella alpha Proteobacteria growth medium before the PCR testing. This increases the diagnostic sensitivity nearly by four times as compared to the conditions when the PCR is done alone. This new method of testing is also known as Bartonella ePCR.

Studies that have been done in this context have revealed the fact that Bartonella is a disease that can also bring about a large trail of other problems as a consequence, such as lymphatic, cardiac, musculoskeletal and problems of the central nervous system. Patients who did have exposure to ticks, fleas, biting flies, body lice and animal bites will be susceptible to this condition all the more.

Diagnosis of Bartonellosis is also done on the basis of a certain symptom such as headaches, fever, muscle pain, insomnia, myalgia, and neurological malfunction. These physical symptoms are a major process of diagnosis that is used by the doctors popularly across the world.

Treatment of Bartonellosis

There is much disparity in the fraternity of medical practitioners when it comes to the treatment of Bartonellosis. No univocal treatment process for Bartonellosis has still been agreed upon by the doctors around the world, which means that the antibiotics that will be prescribed for the situation may vary from situation to situation and from doctor to doctor. Different clinical situations will demand different treatment processes and it will also depend on the extent to which the disease has affected the patient. The prior health condition and the history of the patient will also have an effect on the treatment process followed for the Bartonellosis patient. The antibiotic courses that will be continued for the Bartonellosis patient can continue for a period of two weeks. In certain cases where the situation is really acute, it can also continue for three to four months. Proper testing before administration of medicines and drugs and before taking up a certain course of treatment is really important. This is one of the best ways through which a full proof treatment process can be found for the Bartonellosis patient.

The testing needs to be done for the current condition of the person and yet again also for the past medical conditions that he has suffered from. The weak immune system of a person is mainly responsible for the occurrence of the condition hence proper steps needs to be taken to stabilize this as well. People who have a high exposure to animals, pets, and ones who works in farms and other areas where they need to be in close proximity with animals need to take extra care even after they have tided over the situation.


Further researches are being done into the genre so that better understanding can be attained on the disease. One thing that has been understood till date is that the problem gets triggered off by pet animals or even wild ones (through their scratches and bites, since the saliva is believed to contain the bacteria); certain flies can also be potential hosts of the bacteria. Pet owners must be very careful regarding the way they interact with their pets. People with a suppressed immune system must be extra careful.