Severe Babesia microti infection presenting as multiorgan failure in an immunocompetent host

A previously healthy 67-year-old farmer presented to an outside hospital after a 2-week history of non-specific respiratory symptoms. A certain diagnosis was not initially apparent, and the patient was discharged home on a regimen for presumed chronic obstructive pulmonary disease exacerbation. He re-presented to the emergency department with shock and hypoxaemic respiratory failure requiring prompt intubation and fluid resuscitation. He was then transferred to our institution due to multiorgan failure. On arrival, the patient demonstrated refractory shock and worsening acute kidney injury, severe anaemia and thrombocytopaenia. The peripheral smear revealed absence of microangiopathic haemolytic anaemia. A closer review of the smear displayed red blood cell inclusion bodies consistent with babesiosis. The patient was started on clindamycin and loaded with intravenous quinidine, and subsequently transitioned to oral quinine. A red cell exchange transfusion was pursued with improvement of the parasite load. The patient was discharged home on clindamycin/quinine and scheduled for outpatient intermittent haemodialysis.