February 13, 2012
Leptospirosis is an infectious disease caused by a type of bacteria called a spirochete. Leptospirosis can be transmitted by many animals such as rats, skunks, opossums, raccoons, foxes, and other vermin. It is transmitted though contact with infected soil or water. The soil or water is contaminated with the waste products of an infected animal. People contract the disease by either ingesting contaminated food or water or by broken skin and mucous membrane contact with the contaminated water or soil. The infection causes a systemic illness that often leads to renal and hepatic dysfunction. The disease was first recognized as an occupational disease of sewer workers in 1883. In 1886, Weil described the clinical manifestations in 4 men who had severe jaundice, fever, and hemorrhage with renal involvement. Leptospirosis is also transmitted by the semen of infected animals. Workers may contract the disease through contact with infected blood or body fluids. Though recognised among the world's most common diseases transmitted to people from animals, leptospirosis is nonetheless a relatively rare bacterial infection in humans. The infection is commonly transmitted to humans by allowing water that has been contaminated by animal urine to come in contact with unhealed breaks in the skin, the eyes, or with the mucous membranes. Outside of tropical areas, leptospirosis cases have a relatively distinct seasonality with most of them occurring in spring and autumn.
Leptospirosis is caused by pathogenic spiral bacteria that belong to the genus Leptospira, the family Leptospiraceae, and the order Spirochaetales. These spirochetes are finely coiled, thin, motile, obligate, slow-growing anaerobes. Their flagella allow them to burrow into tissue. The genus Leptospira was originally thought to comprise only 2 species: L interrogans, which is pathogenic, and L...