Cholera in the Time of Covid

ABSTRACT

INTRODUCTION: Cholera is endemic to 50 countries with most US cases acquired during international travel. However, several cases have occurred from the ingestion of local oysters, crabs, and shrimp with resident Vibrio cholerae strains on the Gulf Coast. DESCRIPTION A 52-year-old man with insulin dependent diabetes mellitus and well controlled HIV presented with hypovolemic shock. He reported 4 days of non-bloody diarrhea, poor oral intake, and oliguria. Before symptom onset, he ate crabs and tasted the water they were boiled in. He was prescribed azithromycin outpatient which mildly improved his diarrhea but presented to the hospital due to dizziness. He was initially hypotensive but this improved with 2 liters of normal saline without needing vasopressors. He had a blood glucose of 417 mg/dL, sodium bicarbonate of 13 mmol/L, anion gap of 29, creatinine of 10.5 mg/dL, calcium 8.3 mg/dL and corrected sodium of 124 mmol/L. Lactate and beta-hydroxybutyric acid levels were normal. Prior to admission, he took his insulin despite little oral intake. Given his glucose level and anion gap acidosis, he was placed on an insulin drip for concern of diabetic ketoacidosis (DKA). Stool PCR was positive for Vibrio cholerae and Salmonella enterica. Blood cultures were also positive for S. enterica. He received doxycycline for cholera and 14 days of ciprofloxacin for salmonella bacteremia. During his hospitalization, he got 14 liters of fluids with resolution of electrolyte abnormalities by discharge. DISCUSSION: In this patient, the anion gap acidosis was concerning for DKA but normal ketones made this diagnosis less likely. Cholera infection leads to "rice water" stool outputs up to 200cc/kg/hour in the first 2 days then ending after 4-6 days with profound electrolyte abnormalities. Due to rapid volume loss, patients present in hypovolemic shock with hyponatremia, hypocalcemia and hypoglycemia. Anion gap metabolic acidosis occurs due to acute tubular necrosis as in this patient. Stool culture is the gold standard for diagnosis. Treatment with doxycycline, ciprofloxacin or azithromycin decreases the duration of illness and reduces stool volume by 50%. Despite its rarity in the US, cholera should be considered and promptly treated in patients presenting with copious diarrhea, hypovolemia, and renal failure.