Severe leptospirosis after a rat bite in an urban setting

Leptospirosis is a zoonosis present in every country, but more prevalent in tropical regions, caused by spirochetes of the genus Leptospira. Wild mammals, particularly rodents, represent the most important reservoir of L. interrogans. They carry it in their renal tubules and shed it in their urine. The bacteria can then survive in water or soil. Human infections typically occur after exposure of mucosa or nonintact skin to contaminated urine or environments. Transmission through animal bites is less common but has been reported. Because rats do not shed leptospires in their saliva, temporary contamination of their oral cavity with urine has been suggested as an explanation for transmission through bites. Liberal use of antibiotics after animal bites could explain the low frequency of bite-related leptospirosis. Here, Arbour et al examine the case a 76-year-old man with severe leptospirosis after a rat bite.