Insufficient serological evidence of the association between chronic kidney disease and leptospirosis in Badulla and Kandy districts, Sri Lanka

Objective Chronic kidney disease (CKD) and chronic kidney disease of uncertain etiology (CKDu) are chronic kidney diseases that pose a significant health burden in Sri Lanka. Leptospirosis is a bacterial zoonosis that primarily damages renal tissues by colonization of Leptospira spp. in the renal tubules and is a suspected etiological agent of CKDu. Since Sri Lanka is an endemic for leptospirosis and outbreaks of the disease have been reported, this study aimed to determine the association between leptospirosis and chronic kidney disease in two geographically distinct regions of Sri Lanka, Badulla (CKDu endemic) and Kandy (CKDu non-endemic) districts. Results Eighty-five patients with CKDu and 149 controls from Badulla and 49 patients with CKD and 135 controls from Kandy were serologically tested by microscopic agglutination test with a panel of 11 Leptospira serogroups. The seroprevalence rates for leptospirosis were 7.1% and 13.4% in the CKDu and control groups, respectively, in Badulla and 2.1% and 18.5% in the CKD and control groups, respectively, in Kandy. There were no statistically significant differences between demographic characteristics and leptospirosis seropositivity in the CKD and control groups in either Badulla or Kandy. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study was partly supported by a research grant from University of Peradeniya (URG/2018/28M) and National Science Foundation of Sri Lanka (RPHS/2016/CKDu/06). This funding source had no role in the design of this study and did not have any role during its execution, analyses, interpretation of the data, or decision to submit results. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Ethical approval for this study was obtained from the institutional ethical review committee of the Faculty of Medicine, University of Peradeniya (2016/EC/64). The collection of blood samples and demographic data was approved by the Regional Director of Health Services, Kandy, and informed consent was obtained from all study participants via signature or thumbprints. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Data has been made available as Supplementary Materials * AKI : acute kidney injury CI : confidence interval CKD : chronic kidney disease CKDu : chronic kidney disease of uncertain etiology GFR : glomerular filtration rate MAT : microscopic agglutination test NCP : North Central Province