Monday, December 08, 2008
Leptospirosis Outbreaks in Triathletes and Adventure Sportspeople
Leptospirosis is a bacterial infection of rats and other rodents. It can be transmitted to humans when they swim in fresh water bodies contaminated by rodent urine. Although many American doctors regard this disease as an exotic tropical infection, leptospirosis infections actually occur world-wide. The organism is a spirochete-- a coiled bacteria similar in shape to the organisms that cause syphilis and lyme disease (see electron micrograph pic at left).
Most people who get leptospirosis have a non-specific flu-like illness about a week or two after exposure. About ten percent of patients get serious complications, including kidney and liver failure (Weil's disease). Textbook cases present with subconconjunctival hemorrhage (red eyes), but of course this symptom is hardly sensitive or specific.
I was surprised to learn that there have been several outbreaks of leptospirosis in triathletes and adventure sportspeople. The largest outbreak in the United States was after a triathlon near Lake Springfield in 1998, when 12% of participants reported a post-triathlon febrile illness. Of 474 participant blood samples tested, 11% were spirochete positive (Clin Infect Dis. 2002 Jun 15;34(12):1593-9. Epub 2002 May 24). ] In 2000, there was an outbreak in Athletes who competed in the 10-day Borneo "Eco Challenge 2000, multisport endurance race." The event included jungle walking, swimming, kayaking, spelunking, climbing, and mountain biking. About half the athletes got leptospirosis. There's an interesting report of the epidemiological investigation in CDC's Emerging Infectious Diseases, Sejvar J, Bancroft E, Winthrop K, Bettinger J, Bajani M, Bragg S, et al. Leptospirosis in "Eco- Challenge" athletes, Malaysian Borneo, 2000. Emerg Infect Dis [serial online] 2003 Jun. The CDC suggests that athletes who participate in these events might want to consider taking Doxycycline for pre-adventure sport prophylaxis!