Leptospirosis: A tropical disease in the Midwest
Joshua J. Won
Henry Ford Health System
Introduction: Regional diseases travel across the globe with little difficulty in the modern age. Ease of long-distance travel and importation of exotic goods are the culprit. Leptospirosis is a disea..more »
Introduction: Regional diseases travel across the globe with little difficulty in the modern age. Ease of long-distance travel and importation of exotic goods are the culprit. Leptospirosis is a disease mostly prevalent in tropical countries surrounding the equator, with the incidence of new cases decreasing as you move north. It is a zoonotic disease, with rodents as the common host, contributing to about 900,000 cases worldwide with up to 50,000 deaths per year. There are reported of cases throughout the southern United States, but new cases in the Midwest, or Northern states, are rare. Therefore, acquiring a thorough history, including a detailed history of pertinent exposures is paramount in diagnosing Leptospirosis. With strong suspicion early on the disease course, treatment can be initiated early to prevent poor outcomes.
Case presentation: We present a case of a 50-year-old male, residing in Michigan, who presented to the emergency department with a 5-day history of progressively worsening subjective fevers, nausea and vomiting. The patient was otherwise healthy prior to 5 days ago. He denied any sick contacts, new medications, or any known allergies. The patient denied recent consumption of off-putting food, uncooked meats, or recent travel outside the country. The patient’s vitals on initial presentation were significant for absent fever, hypotension, and tachycardia. His physical exam was unremarkable at the time, aside from his tachycardia. His labs showed leukocytosis to 18,800 with neutrophil predominance, new onset thrombocytopenia at 39,000. He had an acute kidney injury with a creatinine of 4.5mg/dL. A liver profile showed up trending bilirubinemia, mostly direct, and mild transaminitis with ALT in the 60s IU/L and AST 100-120 IU/L. Imaging including RUQ ultrasound and CXR showed now gross abnormalities. The patient was treated for sepsis with broad spectrum antibiotics and fluid resuscitation and admitted to the medical ward. While on the medical ward, his vitals stabilized and his acute kidney injury improved with volume resuscitation. The patient was not feeling better and his lab values were not improving. About 3 days into his hospitalization, the patient started to spike fevers and developed worsening right upper quadrant pain with notable jaundice and sclera icterus. Of note, the patient did not have conjunctival suffusions (present 55% of the time in leptospirosis infections). His liver enzymes continued to rise which prompted a hepatology consultation. His ALT and AST peaked at 171 and 62 IU/L, respectively. Bilirubin peaked at 42 mg/dL, mostly direct. Work up for acute liver injury, short of liver biopsy, was unrevealing. Infectious disease was brought on board due to an unclear source for infection about 3 days into his hospital course. On their evaluation, they caught a key component of his past exposure history, which in this case, revolved around his occupation and home pets. The patient admitted to the infectious disease team, he works as a home exterminator of rats. He also has multiple domesticated pet rats at home. The patient’s overall clinical presentation was consistent with Leptospirosis and he was promptly started on ceftriaxone. Serologies for Leptospirosis were sent out and came back positive for Leptospira IgM, and positive on Leptospira PCR. The patient completed a 7-day course of ceftriaxone and his liver function tests and blood counts improved. The patient made a full recovery.
Discussion: Although rare diseases generally are not on the top of diagnostic differentials, this case presentation shows how adhering to the fundamentals of obtaining a thorough history of present illness can prevent rare diseases from being missed or overlooked. In this case, the patient presented with clinical symptoms of an ongoing infection with an unusual exposure history that was noted later during his hospital course. If the patient’s significant exposures were noted early on, then the treatment may have been initiated sooner, and reducing the risk of complications related to Leptospirosis, or even death.
Henry Ford Hospital
Resident PGY 3
Henry Ford Health System