Case Presentation: A previously healthy 13-year-old female presented to a pediatric emergency department with 5 days of abdominal pain, emesis, headache, arthralgia, and fever. Vital signs included temperature of 100.2 F, heart rate of 122 beats/minute, normal blood pressure for age, and oxygen saturation of 99% on room air. She was ill appearing with bilateral conjunctival injection, diffuse abdominal tenderness, and delayed capillary refill. She did not exhibit meningeal signs. Initial diagnostic testing was significant for anemia (Hb 11.2g/dl), thrombocytopenia (Plt 75,000µ/L), hyponatremia (Na 129mmol/L), hypokalemia (K 2.8mmol/L), and acute kidney injury (Cr 0.88mg/dL). CT of abdomen and pelvis demonstrated enteritis and bibasilar airspace disease. Urinalysis was without evidence of infection. She was volume resuscitated and admitted to the hospital pediatrics service.Once admitted, she was started on empiric ceftriaxone and metronidazole. The patient’s renal function and electrolytes quickly improved. However, with continued systemic symptoms, new oxygen requirement, further worsening of anemia, thrombocytopenia, and negative cultures, expert infectious disease consultation was sought. Empiric treatment for spirochetes with doxycycline was initiated pending broadened infectious testing. In subsequent days, her symptoms improved, and laboratory abnormalities trended toward normal. Ultimately a next-generation sequencing test that detects pathogen cell-free DNA (PcfDNA) resulted positive for Leptospirosa interrogans. Leptospirosa IgM also resulted positive. She was discharged home on hospital day 6 with plans to complete a total of 7 days of treatment with doxycycline.
Discussion: Leptospirosis is a zoonotic condition caused by a spirochete of the genus Leptospira. Reservoir host animals (rodents, dogs, farm animals) excrete leptospires in urine which can live for months in moist soil or warm water. Human transmission occurs via mucosal surfaces or abraded skin. Clinical presentation begins with septic phase which lasts 3-10 days consisting of fever, headache, abdominal pain, emesis, conjunctival suffusion, and myalgia. Without treatment, leptospirosis can progress to the immune phase which can present as aseptic meningitis, Weil syndrome (jaundice and renal dysfunction), pulmonary hemorrhage, and cardiac arrhythmia. While leptospirosis is uncommon in developed countries, further history in this patient did reveal multiple potential risk factors including swimming in stagnant pond water and frequent exposure to animal urine and feces. Her symptoms were emblematic of the septic phase and responded well to treatment. Though she was diagnosed using PcfDNA, the true gold standard is microagglutination test (MAT).
Conclusions: Low prevalence and nonspecific symptoms associated with the acute phase of leptospirosis can make diagnosis challenging. Prompt consideration and initation of antibiotic treatment can prevent life threatening complications. One’s index of suspicion for leptospirosis should be heightened when caring for patients from high risk groups. These include sewage workers, farmers, military, survivors of natural disasters, fresh water recreation enthusiasts, and those who encounter animal waste in their living environment.