Serological evidence of leptospirosis and dengue coinfection in an endemic region in South India

Background: Concurrent epidemics of both dengue fever and leptospirosis are known to occur in the tropics; however, it is unclear whether coinfection is associated with different clinical manifestations and outcomes. Materials and Methods: Medical records for patients with serological evidence of leptospirosis, dengue, and coinfection from January 2007 to December 2008 were abstracted using a standardized abstraction form. The patients' demographic data, underlying diseases, clinical manifestations, laboratory data, and disease outcomes were retrospectively analyzed. Results: The frequency of leptospirosis was 15.8% (287/1814), while that of dengue was 14.8% (239/1610) and coinfection was seen in 1.3% (17/1309). Highest mortality of 29.6% (5/17) was seen in coinfected cases, followed by leptospirosis (14.6%) and dengue (3.7%). Conclusion: In the tropics, leptospirosis and dengue can coexist and increased awareness of coinfection, and an enhanced ability to diagnose it early in illness, will help guide the appropriate use antibiotics and supportive measures to reduce mortality.