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Germs that infect humans

Treponema pallidum

Treponema pallidum

© Dennis Kunkel Microscopy, Inc.

Microorganism: Treponema pallidum is the bacterium responsible for syphilis.

Disease: syphilis

Occurrence of the disease

History: many hypotheses have been proposed to account for the origin of syphilis in Europe. Some authors mention that Christopher Columbus and his crew may have contracted syphilis during their voyage to the West Indies (1492). Others think that syphilis existed many centuries ago in Africa and that it appeared in Europe during the population migrations (1500). During the 16th century, the Italian physician Franscatoro wrote a poem in which he described syphilis "seeds" transmissible by sexual contact. During the 18th century, the term "venereal" was attributed to sexually transmissible diseases, referring to the Roman goddess of love, Venus.

Current situation: fewer than 50 cases of syphilis were reported in Quebec in 1998.

Mechanism of action of the microorganism: the microorganism enters the body through the mucous membranes or scratches on the skin. It then travels to lymph nodes of the infected region and spreads throughout the body.

Symptoms of the disease: rash, hair loss, discomfort, and fever. In untreated cases, syphilis can attack the heart, nerves, eyes, and liver. Mental retardation, blindness, an unsteady gait, and dementia have also been observed. Many of these symptoms have been associated with famous people such as Al Capone and Adolf Hitler.

Incubation period: an average of three weeks

Contagious period: the contagious period is associated with the presence of lesions. The disease is rarely transmitted after the first year of infection.

Hosts: humans

Transmission: syphilis is a contagious disease that can be contracted by sexual contact; it can also be transmitted from an infected mother to her child.

Treatment: antibiotics such as penicillin

Geographical distribution of the microorganism: worldwide

Prevention: use of a condom

Vaccine: not available