Prevalence, clinical, and demographic characteristics of concomitant dengue fever and leptospirosis among acute dengue fever patients in The Western Province of Sri Lanka.

Dengue and leptospirosis are hyperendemic diseases in Sri Lanka. We aimed to determine the prevalence and clinical manifestations of concomitant infections of leptospirosis and acute dengue infection (ADI) in clinically suspected dengue patients. A descriptive cross-sectional study was carried out in five hospitals in the Western Province, from December 2018 to April 2019. Venous blood and sociodemographic and clinical details were collected from clinically suspected adult dengue patients. Acute dengue was confirmed by DENV NS1 antigen ELISA, IgM ELISA, IgG ELISA, and IgG quantification assay. Leptospirosis was confirmed by the microscopic agglutination test and real-time polymerase chain reaction. There were 386 adult patients. The median age was 29 years, with male predominance. Among them, 297 (76.9%) were laboratory confirmed as ADI. Concomitant leptospirosis was present in 23 (7.74%) patients. In the concomitant group, the majority (65.2%) were female, in contrast to ADI (46.7%). Myalgia was significantly more common in patients with acute dengue fever. All other symptoms were similar in both groups. In conclusion, the 7.74% of patients of ADI had concomitant leptospirosis, and it was more common in females.