Multilocus sequence typing of Treponema pallidum pallidum in children with acquired syphilis by nonsexual contact.

Syphilis is a disease caused by the bacterium Treponema pallidum subsp. pallidum (TPA). Although it is considered a sexually transmitted disease, syphilis can also be transmitted by nonsexual close contact with active lesions. There are clinical reports of this route of transmissions in children; however, there are no molecular characterizations of TPA in this population. A multidisciplinary study (epidemiological, clinical, social and molecular) was performed in six children from five families with clinical diagnosis of nonsexually transmitted syphilis. As a result, 18 infected persons were detected. In 16 individuals the presence of the bacterium genetic material was confirmed by molecular biology techniques, and in 12, its strain was analyzed. When we compared the data, we observed that in four families, the child's strain coincided with the one found in close contact, while in one family, this could not be determined. To our knowledge, this is the first report of TPA characterization in children, which underscore the importance of including molecular biology techniques in complex clinical scenarios such as these.