Ciprofloxacin/doxycycline: Lack of efficacy.

A 72-year-old man with a Borrelia afzelii infection experienced a lack of efficacy with ciprofloxacin and doxycycline treatment. He developed a sudden fever and sought medical attention after being bitten by a tick at a deer farm. Despite receiving ciprofloxacin and doxycycline, he died three days after starting the doxycycline treatment. Molecular diagnostic tests confirmed the presence of B. afzelii in his blood, and mutations were discovered. The lack of efficacy of ciprofloxacin and doxycycline in treating the B. afzelii infection was considered a contributing factor to his death. [Extracted from the article]