Extreme Athlete, 18, With Worsening Cough

Laboratory work-up
Diagnosis of leptospirosis is challenging.²¹ Laboratory tests vary, depending on the timing and stage of infection, and are mostly unavailable in resource-poor countries. Test results for the patient with early-phase leptospirosis may demonstrate renal or hepatic abnormalities.¹⁸ However, laboratory confirmation of leptospirosis requires²²
• A fourfold increase in antibody titer between acute and convalescent serum samples, as detected by microscopic agglutination testing (MAT) or
• A high MAT titer (> 1:400 to 1:800), in single or paired samples or
• Isolation of pathogenic Leptospira species from a normally sterile site or
• Detection of DNA from pathogenic Leptospira species by PCR

A positive laboratory result is, of course, confirmatory. However, negative laboratory findings must be viewed with healthy skepticism.¹² A false-negative result may merely indicate the shortcoming of the testing method to accurately assess the presence of Leptospira.

Treatment options
The high mortality rate associated with severe leptospirosis makes early diagnosis and treatment essential.²³ The World Health Organization warns that antibiotic treatment for leptospirosis must be instituted within five days of symptom onset.¹⁰

Treatment options for an ambulatory patient with mild symptoms and no organ involvement include oral doxycycline (100 mg bid for 5-7 d) or oral azithromycin (500 mg/d for 5-7 d). For patients with organ involvement, IV penicillin (1.5 million U every 6 h for 7 d), ceftriaxone (1 g/d for 7 d), or cefotaxime (1 g every 6 h for 7 d) may be considered.^12,20

OUTCOME FOR THE CASE PATIENT
With leptospirosis as the diagnosis of exclusion, Jane was treated successfully with a 21-day course of oral doxycycline (100 mg bid). She has been symptom free since completing the regimen. After undergoing physical therapy and athletic training, she has been able to resume her full exercise regimen, and her recovery is considered complete.

CONCLUSION
The growing popularity of adventure travel and “extreme sports” events, particularly triathlons and mud runs, may precipitate an increase in associated infections with Leptospira and other zoonotic pathogens. For patients with flulike symptoms who routinely engage in such sports—especially those who present with conjunctival suffusion—leptospirosis should be considered in the differential diagnosis.

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