Nonsyphilitic Spirochetosis in Second-Trimester Fetuses

Abstract

Four female fetuses (17–23 weeks) spontaneously aborted by young women (15–19 years old) showed spirochetal microorganisms predominantly in the intestinal lumen and mucosa and to a much lesser extent in other organs. Fetal tissues showed a brisk lymphocytic-plasmacytic response in intestinal mucosa, lungs, and meninges in some cases. In all instances the placenta had chorioamnionitis and severe chronic villitis, with villous vasculitis in some. One fetus had a concomitant cytomegalovirus infection. The observed lesions were reminiscent of Treponema pallidum infections; however, the spirochetes were morphologically different by light and ultrastructural microscopy from T. pallidum and did not react with a silver-enhanced, gold-labeled anti-T. pallidum antibody. In addition, serologic tests for syphilis of the women before or after the abortions were nonreactive. On the basis of clinical pathologic considerations as well as the absence of immunostaining, it is possible also to rule out infections caused by Lyme and relapsing fever Borrelia, Leptospira, and Campylobacter. The spirochetes' prominent tropism for the intestinal tract raises the possibility of a congenital infection with gastrointestinal spirochetal species described in recent years. The placental findings suggest an ascending transamniotic infection, with initial colonization of the intestinal tract and systemic dissemination of the organisms in the fetus and placental villi.

Key Words:

• fetal infection
• spirochetal infection
• placentitis
• intestinal spirochetosis