Case Presentation: A 29-year-old woman presented with a 4-day history of nausea, vomiting, and watery, non-bloody diarrhea. She also had fever, headache, and dark urine. She had traveled to Puerto Rico one-week prior, where she ate raw fish and vegetables and drank tap water. She also went to visit a waterfall, where she swam in nearby fresh water ponds and lakes. Her initial vitals were a T of 37 C, HR 104, RR 18, and BP of 132/80 with normal oxygen saturation. She appeared ill. She had conjunctival suffusion, scleral icterus, dry mucous membranes, as well as diffuse abdominal tenderness and jaundiced skin. Cardiovascular, respiratory, neurologic, and dermatologic exam were unremarkable. Initial studies were notable for thrombocytopenia, hyponatremia, hypokalemia, acute renal failure, elevated transaminases, and elevated total and direct bilirubin. There was a mild leukocytosis and normal hemoglobin. Urinalysis revealed hematuria, pyuria, and mild proteinuria. Coagulation studies including fibrinogen and ADAMTS13 activity were normal. Blood cultures were negative. Stool studies for ova and parasites, leukocytes, and bacterial toxins were negative. Serologies for HIV, viral hepatitides, Zika, and Dengue viruses were negative. Leptospira IgM antibody was positive. She received hydration and one dose of piperacillin/tazobctam. After antibiotic administration, her temperature spiked to 40.6 C and her blood pressure dropped to the 80s/40s. She required norepinephrine infusion briefly. By the morning, she defervesced and was started on ceftriaxone. She remained hemodynamically stable and laboratory abnormalities resolved.
Discussion: This traveler presented with a diarrheal illness associated with thrombocytopenia, acute non-oliguric renal failure, and liver dysfunction – findings characteristics of leptospirosis. The high fever and hypotension that occurred after the first dose of antibiotics were likely a Jarisch-Herxheimer reaction, which occurs in about 20% of patients treated for leptospirosis.
Leptospirosis is a zoonosis caused by spirochetes, which occurs in both temperate and tropical climates. Infection occurs through exposure to animal urine, often found in contaminated water or soil. Risk factors for travelers include recreational activities such as fresh water swimming, kayaking, etc.
The clinical manifestation of leptospirosis is variable, from self-limited illness to fatal disease. Diarrhea and vomiting occur in about 50% of cases. Conjunctival suffusion is a common and specific sign of leptospirosis. Complications include liver dysfunction, non-oliguric renal failure, pulmonary hemorrhage, ARDS, and aseptic meningitis. Common laboratory findings include thrombocytopenia, hyponatremia, hypokalemia, and sterile pyuria. Interestingly, the electrolyte derangements are directly caused by leptospira, whose outer membrane protein inhibits the Na-K-Cl co-transporter in the thick ascending limb.
Most cases of leptospirosis are self-limited; however, antibiotic treatment can shorten the duration of symptoms and decrease shedding of leptospira in the urine. The preferred treatment regimens are oral doxycycline or azithromycin, or intravenous penicillin, doxycycline, or ceftriaxone for patients with severe illness. The duration of treatment is 7 days.
Conclusions: While the differential diagnosis of diarrhea in returning traveler is broad, the association of acute non-oliguric renal failure and liver dysfunction can point a hospitalist toward leptospirosis.