Serum nitrite levels in Sri Lankan patients with leptospirosis

To determine whether blood nitrite levels are elevated in patients with leptospirosis.

Male patients fulfilling clinical and epidemiological criteria for a diagnosis of leptospirosis were recruited. Those with MAT titre of ≤400 together with those seroconverting to a titer of ≤200 were included in the analysis. Serum nitrite levels were measured in these patients and age, sex matched healthy controls.

Patients from 3 hospitals (n=75) were screened during a 3 month period from 28th June to 3rd September 2009, of whom 20 were eligible for the study. Serum nitrite levels were found to be significantly higher in patients with acute leptospirosis [n=20, (0.359±0.229)μ M] compared to controls [(n=13,(0.216±0.051)μ M](P=0.014). A significant correlation was also observed between the MAT titre and the day of illness (r = 0.547; P<0.0001).

Serum nitrite levels are higher in patients with acute leptospirosis compared to age and sex matched controls. No correlation could be assessed with severity of illness, as sample size was inadequate to determine this.