Babesia microti infection and hemophagocytic lymphohistiocytosis in an immunocompetent patient

Abstract

Babesiosis is a rare and potentially severe tick-borne illness endemic to the Northeastern and upper Midwestern regions of the USA. Hemophagocytic lymphohistiocytosis is an uncommon condition resulting from over-activation of the immune system. The first known case of babesiosis and hemophagocytic lymphohistiocytosis in an immunocompetent patient is reported here.

Hemophagocytic lymphohistiocytosis secondary to Babesia in an immunocompetent adult

“…To our knowledge, our case is the first reported in an immunocompetent adult younger than age 40 who developed HLH secondary to Babesia. In our case, as well as in the previous four reported cases of HLH secondary to babesiosis, clinical improvement with symptom resolution occurred within 3‐7 days of initiating antibiotics against babesia …”

“…Three previous cases of HLH secondary to Babesia have been reported in elderly immunocompetent patients . One additional case of HLH secondary to babesiosis was reported in 1986 in a 54 year old homosexual male who did not have any reported history of immunosuppression .…”

The unusual case of babesiosis causing disseminated intravascular coagulation with hemophagocytic lymphohistiocytosis

“…It is common for infected people not to recall a tick bite, as they can be as small as a poppy seed when sporozoites become transmissible. Sporozoites subsequently enter erythrocytes and undergo asexual replication leading to red blood cell (RBC) lysis 1,3 . Clinical manifestations range from asymptomatic to severe fulminant disease, leading to hemolytic anemia, thrombocytopenia, hemophagocytic lymphohistiocytosis (HLH), splenic rupture, or even disseminated intravascular coagulation (DIC) 4 …”

“…Babesiosis is an intra-erythrocytic Protozoan infection, transmitted through the Ixodes scapularis ticks (also called black-legged or deer ticks), most commonly found in the Northeastern and upper Midwestern regions of the United States (US). 1 Babesia microtii is most frequently found in humans, and the CDC has reported approximately 2000 cases each year. 2,3 It is common for infected people not to recall a tick bite, as they can be as small as a poppy seed when sporozoites become transmissible.…”

“…Sporozoites subsequently enter erythrocytes and undergo asexual replication leading to red blood cell (RBC) lysis. 1,3 Clinical manifestations range from asymptomatic to severe fulminant disease, leading to hemolytic anemia, thrombocytopenia, hemophagocytic lymphohistiocytosis (HLH), splenic rupture, or even disseminated intravascular coagulation (DIC). 4 The major risk factors for these life-threatening complications primarily include immunocompromised status, asplenic patients, and those 60 years of age or older.…”