Kali Hardig , 12 , continues to make progress at Boston Children 's Hospital . Hardig is walking with difficulty during treatment sessions , hospital spokesman says . Amoeba causes fatal brain infection , according to the WHO . Parasite generally found in people who swim in warm , fresh water .
Kali Hardig , 12 , continues to make progress at Arkansas Children 's Hospital . Hardig is walking with assistance during therapy sessions , hospital spokesman says . Amoeba causes fatal brain infection , according to the CDC . Parasite generally found in people who swim in warm , fresh water .