Bartonella Infection

Bartonella – Intracellular Parasites 

Bartonella, a genus of Gram negative bacteria lives in cells and could infect humans, mammals as well as wild animals though not all Bartonella species cause disease in humans. They are intracellular parasites which show preference for erythrocytes and endothelial cells in the human body. Bartonella bacteria are said to be carried by fleas, body lice and ticks and cats are said to be the main reservoir for B. henselae that causes around 20,000 reported case of cat scratch disease every year in the U.S. Cat scratch disease is the most common zoonotic infection which is caused by Bartonella bacteria and cats represent a large reservoir for human infection since they are the main reservoir for Bartonella henselae, Bartonella clarridgelae as well as Bartonella koehlarea. Bactonella spp. are vector borne bacteria and the transmission of B.henselae through cat fleas takes place through infected flea faeces though new vectors such as ticks and biting flies have been identified.

Several Species of Bartonella 

Scientists are of the opinion that ticks are a source of infection in the case of some humans while people with tick bites and no known exposure to cats have also acquired the disease. People who seem to be bitten by ticks have been infected with Lyme and Bartonella though further study needs to be done to identify the role of ticks in spreading the disease. Scientist has come across several species of Bartonella and one is carried by sand flies in Andes Mountain in Peru, Ecuador while another is found worldwide in human body lice. Bartonella bacteria has also been found in European sheep tick and five different types of Bartonella species have been identified in 19.2% of I.pacificus ticks which were collected in California.

Symptoms 

Cat spread disease – CSD is clinically diagnosed in patients with signs and symptoms with compatible exposure history. Serology confirms the diagnosis though cross reactivity could limit interpretation in some cases. B.henselae DNA could also be detected by culture of pus or lymph node aspirates on using special techniques while trench fever could be diagnosed by isolation of B.quintana from blood cultured on blood or chocolate agar under five percent CO2 and micro-colonies is seen after a period of incubation of1 – 3 weeks at 37 deg. C.

It can also be diagnosed by serology. Carrion’s disease is diagnosed through blood culture or through direct observation of the bacilli in peripheral blood smears at the time of acute phase of infection.Bartonella is said to be mild though in some serious cases it could affect the whole body where the early symptoms are fever, headache, fatigue, loss of appetite with unusual streaked rash. Swollen glands could be typical around the head, neck and arms.

Bartonella is sensitive to various antibiotic or vitro though the in vivo performance of these antibiotics in humans as well as domestic pets does not tend to co-relate well, with in vitro laboratory research and most likely it stems from two factors – mostly all antibiotics are bacteriostatic against Bartonella instead of bactericidal and the pathogen is often sequestered in erythrocytes.