Brucellosis
Brucellosis, also called undulant fever or Malta fever, is a zoonosis (infectious disease transmitted from animals to humans) caused by bacteria of the genus Brucella. It is primarily a disease of domestic animals (goats, pigs, cattle, dogs, etc) and humans and has a worldwide distribution, mostly now in developing countries.
The disease is transmitted either through contaminated or untreated milk (and its derivates) or through direct contact with infected animals, which may include dogs, pigs, camels and ruminants, primarily sheep, goats, cattle, bison. This also includes contact with their carcasses. Parturition rests are extremely rich in highy virulent brucellae . Brucellae, along with leptospira have the unique property of penetrate through intact human skin, so infection by mere hand contact with infectious material is likely to occur.
The disease is now usually associated with the consumption of unpasteurized milk and soft cheeses made from the milk of infected animals and with occupational exposures of veterinarians and slaughterhouse workers. Some vaccines used in livestock, most notably B. abortus strain 19 also cause disease in humans if accidentally injected. Problems with vaccine induced cases in the United States declined after the release of the RB-51 strain developed in the 1990s and the relaxation of laws requiring vaccination of cattle in many states.
The incubation period of brucellosis is, usually, of one to three weeks, but some rare instances may take several months to surface.