Author(s): Nalaka J Herath1 , Senanayake AM Kularatne2 , Kosala GAD Weerakoon3 , Abdul Wazil4 , Nilakshi Subasinghe4 and Neelakanthi VI Ratnatunga5
Leptospirosis is a globally prevalent important zoonosis caused by pathogenic strain of Leptospira an aerobic spirochete. Transmission of the disease to human occurs usually through contact with water or soil contaminated by urine of larger array of infected animals [1, 2]. Leptospirosis has become an important public health problem in Sri Lanka, a country which has agriculture based economy where farmers have become the common victim of the disease. Major outbreaks of leptospirosis were frequent in different parts of the island and the year 2008 showed one of the worst outbreaks in the Central Province of Sri Lanka in which many pathogenic serovars were identified . In this outbreak, a single tertiary care hospital alone managed 227 cases, of them 9 patients developed severe acute kidney injury (AKI) who needed dialysis support . The incidence of AKI in leptospirosis varies from 10% to 60%, depending on multiple factors such as age, severity of the disease and the causative serovars of a region .
The renal involvement in leptospirosis can vary from a subclinical course, with mild proteinuria and abnormal urinary sediments to an overt AKI. The AKI usually presents with a rapid elevation in blood urea and creatinine, and can be associated with jaundice. Kidney injury in patients with hyperbilirubinaemia represents a severe form of the disease frequently accompanied by oliguria or anuria . On the contrary, AKI also presents in the non-oliguric form with hypokalaemia in 41% to 45% of the patients with leptospirosis . Renal impairment is a frequent complication in severe disease mainly characterized by interstitial and tubular damage . The contributory factors for development of AKI could be the acute infection of the kidney with the pathogen or an immune mediated renal damage. In addition, haemodynamic alterations, hyperbilirubinaemia and rhabdomyolysis are also associated with the genesis of AKI in leptospirosis [6, 7]. The outcome of AKI if managed properly is fair, but a significant proportion could succumb to it . There are hardly any follow up data of long term renal outcome in leptospirosis in the literature. This study aims to assess the long-term renal outcome of AKI caused by leptospirosis.
Study setting and sample selection
The study was carried out at two Teaching Hospitals in Kandy district of Sri Lanka (Peradeniya and Kandy). Hospital records of patients who had developed AKI following leptospirosis during the period of 2007 to 2010 were studied. These patients had been followed up at least for one year in the out patient clinics with regular assessment including renal status. The relevant clinical data and investigation results were collected from the hospital records. Further clinical assessments of the patients were done at the outpatient clinics and necessary additional details were documented. Moreover, we were able to retrieve renal histology reports of two patients who had undergone renal biopsies 6 month after the initial infection...