Advanced Molecular and Microscopic Diagnostics Suggest Congenital Borrelia Transmission: A Case Report

Congratulations to Dr. Bemis and collaborators!

Dr. Lynne Bemis et al published an article titled “Advanced Molecular and Microscopic Diagnostics Suggest Congenital Borrelia Transmission: A Case Report” in the journal Microorganisms 14, no. 2: 406. The article was published Feb 9 2026.  

Lyme disease is the most common illness spread by ticks in the Northern Hemisphere. It is caused by a type of bacteria called Borrelia, which is usually passed to people through tick bites. In rare cases, however, the bacteria may be passed from a pregnant mother to her baby before birth.

In this study, researchers examined a stored placenta sample and found intact Borrelia bacteria using imaging and molecular studies. After the child was born, both the mother and child showed signs of exposure to Borrelia, even though standard Lyme disease blood tests did not come back positive.

Years later, scientists were able to grow live Borrelia bacteria from samples taken from both the mother and the child. Genetic testing showed that the bacteria in both were the same species: Borrelia burgdorferi, the main cause of Lyme disease in North America. Together, these findings suggest that Lyme disease bacteria can sometimes be passed from mother to child without the involvement of a tick.