Role of Real Time PCR Quantization in Diagnosis and Prognosis of Leptospirosis and Analysis of the Association between Bacterial Load and Various Complications

Abstract

Introduction: Leptospirosis is considered as an underreported and underdiagnosed disease. There is paucity of data regarding the incidence of leptospirosis from Mysore, Karnataka. This study throws light into the incidence of leptospirosis and the recent developments in the diagnostic techniques used in the laboratory. Aim: This study aims to analyse the use of Real-Time PCR for diagnosis of leptospirosis and to compare the association of bacterial load with various complications. Materials and Methods: This study was carried out from April 2013 to April 2016 in a tertiary care center, Mysore, Karnataka, India. Hundred conventional PCR positive cases for leptospirosis were included in this study so as to determine the bacterial load. Ethical clearance was obtained from the institutional ethical committee. Details of patient including the sample number, patient name, age, sex, date of collection, address, duration of illness, and symptoms of the illness were also recorded. Human blood samples were collected for the study and Real Time PCR was used to determine the copy number present in each leptospirosis suspected sample. The correlation of bacterial load and various laboratory parameters was done using Spearman’s Rank correlation coefficient. Results: Out of the 100 in-house PCR positive cases, only 43 gave a positive result with Real-Time PCR. An increased bacterial load was seen associated with meningitis combined with thrombocytopenia and hepatomegaly. Patients with chronic kidney disease also showed high bacterial load. It was difficult to categorize complications based on the bacterial load as majority of the complications fell in the least and the highest bacterial load category. Conclusion: The Real-Time PCR did not prove to be successful in the early diagnosis of the disease during this study period which may be either due to prolonged storage of DNA or lack of precision of the kit.

Keywords

• laboratory parameters
• leptospira
• prognostic markers
• quantitative polymerase chain reaction