Laboratory parameters of the leptospira sero-positive cases were also studied. Hyperbilirubinema was noted in 103 sero-positive patients, out of which 80 patients had Grade IV hyperbilirubinemia. Direct bilirubin (>0.2mg/dl) was elevated in 90 sero-positive cases. The mean values of liver enzymes AST and ALT were found to be 197.25U/L and 159.85U/L respectively. Liver enzymes (AST, ALT) were elevated in 108 patients. The mean Blood urea and creatinine levels were 183mg/dl and 4.4mg/dl respectively. Blood urea was elevated (>40mg/dl) in 98 sero-positive patients. The creatinine levels were elevated (>1.3mg/dl) in 104 patients, out of which 45 patients had creatinine levels more than 5mg/dl. The mean leucocyte count was 1.5X 103 cells/mm3, leucocytosis was seen in 85 patients. Hepato-renal dysfunction was seen in 64.2% (97/151) of the leptospira sero-positive cases. Mean haemoglobin and platelet count were 10.41g/dl and 125 X 1000/mm3 respectively. Anaemia and thrombocytopenia were seen in 118 and 97 sero-positive patients respectively. The C-Reactive Protein was elevated in 57/59 cases. Pancreatic involvement in the form of elevated amylase in 6 patients and elevated lipase in 9 patients was also seen [Table. 4].

On enquiring about the patient outcome, information could be obtained from 57 patients. 15/57 patients expired; 35 patients recovered. However, 7 patients had developed renal impairment following leptospirosis and had to undergo dialysis.

Leptospirosis is a frequently under-diagnosed infection because of its varied manifestations and difficulty in distinguishing it from other febrile illnesses. Failure to provide timely diagnosis of leptospirosis cases may lead to unnoticed cases developing acute fatal illness[11]. Our study describes the seroprevalence along the detailed analysis of the abnormalities in the hepatic, renal function parameters in patients with leptospirosis.

The seroprevalence of leptospirosis was found to be 27.9%. In a study done by Kalita et al from Northeast India in the year 2008, the prevalence was found to be 22.57%[12]. From these findings it is evident that there has been an increase in the seroprevalence of leptospirosis in our part of the country which may be due to the better availability of diagnostic tests and also because of episodes of floods in the monsoon season along with urban waterlogging. In a 10- year study done by Chaudhuryet al. from northern India, the seroprevalence of leptospirosis was reported to be 26.90 %[13]. The sero-positivity rate of leptospirosis as per studies conducted from other parts of the country ranges from 17.8–40.5%[14].

In the present study, hepato-renal dysfunction was seen in 64.2% (97/151) of the leptospira sero-positive cases, majority of which belonged to the 15-40 years age group (32.4%) i.e. in the young population followed by 40-60 years group (24.5%). A significant correlation was found between age of the patients and hepatorenal dysfunction (p value is 0.028). The higher number of hepato-renal dysfunction in the 15-40 years age group could be due to the fact that majority of leptospira sero-positive cases were detected in this age group in this study i.e., 58.9% (89/151) were in the age group of 15-40 years. Such clustering of the cases in the age group of 20-40 years has been observed by many other studies[5, 12, 15-19]. The reason for the higher seropositivity in this age group can be explained by the fact that they contribute the majority of the outdoor working population. And since this disease affects the productive age group, this has lot of economic burden both on the family and society[20].

In a study done by Goyal et al, hepatic dysfunction was present in 72.5% patients[8]. Various other studies are shown varying degrees of hepatic and renal involvement in leptospirosis patients[5, 21-23]. The mean serum bilirubin in the present study was 14.6 mg/dl, which is similar to that reported in previous studies[5, 8, 24]. The mean serum transaminases values in our study were similar to that reported by Sethi et al. but higher than those reported by Clerke et al. [40-50 U/L][5, 24]. The creatinine levels were elevated in 104 patients, out of which 45 patients had creatinine levels more than 5mg/dl. Seven patients developed renal failure and had to undergo dialysis. Pancreatic involvement was seen in nine patients with elevated amylase/lipase levels.

The male to female ratio was found to be 3.3:1. Males were found to be at higher risk of being seroreactive than females (P value = .00053). This finding is consistent with various other studies where the prevalence was found to be higher in males[12, 13, 15, 16, 25]. This may be generally attributed to men being more involved in agricultural and animal husbandry related activities, as animals are the major sources of infection for humans.

Majority of the leptospirosis patients were farmers (30.6%) and history of exposure to risk factors like animal exposure, living in flood affected areas could be elicited from 66.1% patients. Also, the sero-prevalence of leptospirosis was found to be more the rural districts. Similar findings were reported by some studies where the prevalence of leptospirosis was found to be more in rural areas[5, 8, 25]. However, the prevalence of leptospirosis was found to be more in urban areas as reported by Shukla et al.[26]

Fever was the most common presentation seen in 65/71 (91.5%) cases followed by jaundice in 51/71 (71.8%). These findings are similar to studies done by Kanan et al., Agarwal et al. and Mandal et al.[14, 27, 28]

On analyzing the haematological parameters, leucocytosis was seen in 64.8% (85/131) of the patients. Leptospirosis being a bacterial infection, leukocytosis with neutrophilia is seen[29]. Anaemia and thrombocytopenia were seen 78.1% (118/151) and 74.6% (97/130) of the sero-positive patients respectively. The thrombocytopenia was significant in patients with leptospirosis in this study, which is observed in various Indian studies as well[23, 30].

Leptospirosis is an emerging zoonosis. It affects mainly the working-age group with a predominance toward male thus having a major economic impact on the family and the country. Hepato-renal dysfunction in leptospirosis is common and especially more so in the younger age groups leading to long term complications. The increased awareness among physicians of protean clinical manifestations of leptospirosis, effective monitoring of the laboratory parameters along with timely intervention can reduce the mortality and morbidity associated with the disease.

Limitations of the study: Paired sera were not used for Leptospira IgM ELISA testing which could have given better results. Also scoring as per the Modified Faine’s Criteria was not done as the detailed clinical history was not available from all sero-positive cases.

Funding: No funding sources

Conflict of interest: None declared

Ethical approval: The study was approved by the Institutional Ethics Committee.