Bartonella quintana: Also called Rochalimaea quintana, this microorganism is an unusual rickettsia that can multiply within the gut of the body louse and then can be transmitted to humans. Transmission to people can occur by rubbing infected louse feces into abraded (scuffed) skin or into the conjunctivae (whites of the eyes).
Bartonella quintana (B. quintana) is the cause of trench fever, a disease that was first recognized in the trenches of World War I, when it is estimated to have affected more than a million people in Russia and on the fronts in Europe. Trench fever was again a major problem in the military in World War II and is seen endemically in Mexico, Africa, E. Europe, and elsewhere.
Urban trench fever occurs among the homeless people and people with alcoholism today. Outbreaks have been documented, for example, in Seattle, Baltimore (among injection-drug users), Marseilles (France) and Burundi.
The fever of trench fever is classically a 5-day fever (“quintan fever”). The onset of symptoms is sudden with high fever, severe headache, back pain and leg pain and a fleeting rash.
Recovery takes a month or more. Relapses are common.
It is now clear, that at least in its urban form among the homeless, trench fever can cause bloodstream infection (bacteremia) associated with nonspecific symptoms or no symptoms (New England Journal of Medicine 340: 184-189, 1999).
B. quintana also has been found responsible for a disease called bacillary angiomatosis in people infected with HIV and for infection of the heart and great vessels (endocarditis) with bloodstream infection (bacteremia). The full spectrum of disease caused by B. quintana is still unfolding.
- Bartter syndrome
Bartter syndrome: A group of disorders that are inherited in an autosomal recessive manner and are characterized by impaired salt reabsorption by the kidney with pronounced salt wasting, hypokalemia (low blood potassium), alkalosis (an alkaline body pH), and hypercalciuria (high urine calcium).
- Basal cell carcinoma
Basal cell carcinoma: The most common type of skin cancer, which commonly presents as a sore that seems to get better and then recurs and may start to bleed. Basal cell carcinoma often occurs on the face and neck, where the skin is exposed to sunlight. These tumors are locally invasive and tend to burrow […]
- Basal cells
Basal cells: Small, round cells found in the lower part, or base, of the epidermis, the outer layer of the skin.
- Basal ganglia
Basal ganglia: A region of the base of the brain that consists of three clusters of neurons (caudate nucleus, putamen, and globus pallidus) that are responsible for involuntary movements such as tremors, athetosis, and chorea. The basal ganglia are abnormal in a number of important neurologic conditions, including Parkinson’s disease and Huntington’s disease.
- Basal metabolic rate
Basal metabolic rate: A measure of the rate of metabolism. For example, someone with an overly active thyroid will have an elevated basal metabolic rate.