Babesiosis is a common Lyme disease coinfection. It’s caused by Babesia parasites, most often B. microtia,  which infect red blood cells. Babesia is transmitted by the same ticks that carry Lyme disease, the black-legged tick, but it can also be transmitted during blood transfusions or congenitally from mother to baby. Symptoms of Babesiosis include fever, chills, headache, fatigue, hot flashes, nausea, dark urine, and more. It becomes serious with the onset of thrombocytopenia, disseminated intravascular coagulation, hemodynamic instability, acute respiratory distress, renal failure, hepatic compromise, and altered mental status.