A Fish Farmer's Encounter With Leptospirosis: A Case Report

Leptospirosis is a zoonotic infection primarily caused by bacteria of the genus Leptospira. This infectious disease mainly occurs through direct contact with infected animals or indirect contact via contaminated soil or water. While the incidence rate of leptospirosis in the developing world is as high as 100 cases per 100,000 population, the incidence rate in the United Kingdom is low (0.14 cases per 100,000 population). We present a 56-year-old male fish farmer who presented to the emergency department with a history of intense thigh pain and sudden inability to mobilise following a week-long period of a flu-like illness, characterised by worsening myalgia localised to the inner thighs, fever, and episodes of passing dark red urine. Initial investigations demonstrated acute renal impairment, hepatitis, thrombocytopenia, mild rhabdomyolysis and raised inflammatory markers. With a suspected diagnosis of leptospirosis after a detailed clinical history and preliminary blood tests, treatment was immediately commenced with intravenous antibiotics, intravenous rehydration and vigilant monitoring of urinary output. The patient’s condition rapidly improved and the diagnosis was later confirmed by a positive Leptospira polymerase chain reaction (PCR) report and serology. We believe prompt treatment prevented deterioration in this case. The aim of this case report is to highlight the importance of a detailed clinical history, with a particular focus on occupational exposure, especially in the developed world. Additionally, a low clinical threshold for leptospirosis is imperative, as rapid clinical deterioration can happen if no immediate medical intervention is performed.