An Unfortunate Outing

Introduction: Tickborn illnesses are increasing in prevalence in part because of more ticks surviving milder winters. Here we present a case of AKI secondary to babesiosis induced hemolysis in a self described lifelong city dweller who spent all her life in Manhattan without travelling, except one excursion to the lower Hudson valley for a wedding where she noted an insect bite after a group hike. Case Description: A 66 year old woman with a history of MGUS and breast cancer treated with lumpectomy, radiotherapy and on hormone therapy presented with fever, nightsweats, weight loss, dyspnea and weakness for three weeks. A month before falling ill she had noted an insect bite after a group hike on a wedding. She was cachectic on exam. The patient had pancytopenia WBC 2.8 Hb 6.5g/dl Plat 124, elevated LDH 1057U/L, acute kidney insufficiency with creatinine 1.44mg/dl and mildly elevated bilirubin 1.3g/dl, ALT 50U/L, AST 72U/L. Albumin was low 2.4g/dL, CK was normal, HIV was negative, a Coombs test was negative, her blood group was A positive, ADAMST13 activity was mildly decreased 63%, C3 low 64mg/dl and haptoglobin was undetectable. No schistocytes or inclusion bodies were seen on a blood smear. The urinalysis showed moderate blood with no RBC, typical for free heme as in hemolysis or rhabdomyolysis. The patient's AKI and mild hyponatemia resolved with IV saline. A diagnosis of babesiosis was made by PCR. There was no coinfection by oher tick borne pathogens. The patient was successfully treated with Atovaquone and azithromycin and all symptoms resolved. . Discussion: The patient had pigment induced AKI from hemolytic anemia secondary to babesiosis. Babesia is a parasitie that utlizes RBC similar to malaria but without a liver phase, a smaller genome and not responding to artemisins. Babesiosis can cause severe illness in the elderly and the immunocompromised as this patient, who is a cancer survivor. As with malaria, certain blood groups reportedly have a protective effect but did not protect our patient (Non-B and Rhesus positive). A diagnosis of babesiosis is unexpected in a self described life long Manhattan resident who does not travel but went on a single outing to the countryside for a wedding. Babesiosis is an emerging global health problem and this patient illustrates how the numer of cases of babesiosis are likely to increase, even in unexpected places.