Image source: http://www.frontiersin.org/files/Articles/82508/fmicb-05-00213-HTML/image_m/fmicb-05-00213-g001.jpg
Brucellosis, also called undulant fever, or Malta fever, in humans is a highly contagious zoonosis (infectious disease transmitted from animals to humans) caused by bacteria of the genus Brucella. Brucella spp. are small, gram-negative, non-motile, non-spore-forming rods. Brucella spp. are facultative intracellular parasites causing chronic disease, which usually persists for life. Brucellosis is a bacterial disease of both humans and animals recognized since the 19th century.
Brucellosis is a typical zoonotic disease and it spreads from animal to man but it does not spread from man to man. Fever, chills, sweating, malaise, weakness and various types of pains occur in man.Acute brucellosis causes intermittent or undulations of temperatures.
So this fever is also known as undulant fever. But these types of symptoms do not occur in all the brucella infections and can be seen only in some.
Symptoms of Brucellosis
The incubation period of Brucellathe time from exposure to the bacteria to the start of symptomsis typically about three weeks. The primary complaints are weakness and fatigue. An infected person may also experience muscle aches, fever, and chills.
Ultimately, brucellosis can affect almost any part of your body, including your reproductive system, liver, heart and central nervous system. In some people, brucellosis becomes chronic, with signs and symptoms persisting for years, even after treatment. Why certain people develop chronic disease isn't entirely clear, though it may be due, at least in part, to differences in the way the immune system responds to the bacteria.
The disease is not usually fatal, but the intermittent fevers (a source of its nickname, "undulant fever") can be exhausting. Symptoms usually appear between five days and a month after exposure and begin with a single bout of high fever accompanied by shivering, aching, and drenching sweats that last for a few days.
Brucellosis is characterized by a fever which may be continuous, intermittent or irregular. Some other possible symptoms include headache, weakness, sweating, chills, arthralgia (pain in the joints), depression, weight loss and generalized aching. This disease may last for days, months, or as long as a year if untreated.
Causes of Brucellosis
Brucella bacteria infect cattle, goats, camels, dogs, and pigs. Transmission of the disease to humans occurs by contact with infected meat, contact with the placenta of infected animals, or eating or drinking unpasteurized milk or cheese.
Direct person-to-person spread of brucellosis is extremely rare. It also spreads to the uterus, placenta and prostate gland as well as other internal organs at times.
Approximately 100 - 200 cases occur in the U.S. each year. People working in jobs requiring frequent contact with animals or meat -- such as slaughterhouse workers, farmers, and veterinarians -- are at high risk.
Most people get brucellosis from contaminated dairy products. The bacteria are found in the milk of infected animals, and can spread to humans in unpasteurized milk, ice cream, butter and soft cheeses. Whether hard cheese, yogurt and cultured milk are just as likely to harbor the bacteria is a matter of some debate. The bacteria can also be transmitted in raw or undercooked meat from infected animals.
The ultimate prevention of human Brucellosis rests with the elimination of the disease from animals. Brucellosis may be caused by the nonmotile, and nonspore-forming. It may also cause reoccurring fever and arthritis. Humans are generally infected in one of three ways: eating or drinking something that is contaminated with Brucella , breathing in the organism.
