Introduction. Co-infection of leptospirosis–malaria is not uncommon due to their overlapping geographical distribution in the tropics. Aim. This study aimed to describe and compare the demographic, clinical and laboratory features of leptospirosis–malaria co infection (LMCI) against leptospirosis mono-infection (LMI) in Peninsular Malaysia. Methodology. Data of patients admitted to various hospitals in Peninsular Malaysia from 2011 to 2014 diagnosed with lepto spirosis in our laboratory were obtained from their admission records. Co-infections with malaria were identified via blood film for malaria parasites (BFMP). Description with inferential statistics analysis and multiple logistic regressions were used to distinguish features between dual and mono-infections. Results. Of 111 leptospirosis-positive patients, 26 (23.4%) tested positive for malaria. Co-infections were predominant among male patients with a mean age of 33years and were prevalent among immigrant populations who had settled in high-density suburban areas. Chills and rigor with splenomegaly were the only significant distinguishing clinical features of LMCI while leukocytosis and raised transaminases were significant laboratory parameters. Only chills and rigor demonstrated a predictive value for LMCI from analysis of multiple logistic regressions. No death was attributed to co-infection in this study, in contrast to LMI (11.8 %, n=10). Conclusion. The significant prevalence of LMCI found in this study with overlapping demographic, clinical and laboratory parameters makes diagnosis of co-infection challenging. It is essential to evaluate co-infection in endemic areas. Strengthened awareness of LMCI, comprehensive diagnostic services and further prospective studies are warranted.

Leptospirosis causes a wide range of clinical outcomes, including organ failure and death. Earlytreatment significantly increases the chances of cure. Interleukin-8 (IL-8) is a chemoattractant cytokine for neutrophil and is associated with multiple organ failure. Research has indicated IL 8 to be raised in severe and fatal cases of leptospirosis, but its suitability as a prognostic biomarker has yet to be confirmed. This study aimed to evaluate the significance of IL-8 with the clinical outcomes of leptospirosis patients. Plasma IL-8 was measured in fifty-two samples from hospitalized patients and nineteen healthy controls. The comparisons were made between mild, severe-survived and fatal groups identified by clinical or laboratory findings. IL-8 was significantly higher in fatal (p = 0.01) compared to mild cases. IL-8 was also significantly higher in fatal (p = 0.02) when compared to survived cases of leptospirosis. IL-8 levels in the plasma of fatal leptospirosis cases were significantly elevated compared to survived cases and may serve as a potential prognostic biomarker in determining the possible outcome of leptospirosis patients.