Cryptosporidiosis surveillance -- United States, 2011-2012.

Future research is needed to address the evolving epidemiology of cryptosporidiosis cases, with a specific focus on the increase in nonconfirmed cases and increasing incidence rates among elderly adults. National systematic genotyping and subtyping of Cryptosporidium isolates could also help elucidate Cryptosporidium transmission and thus cryptosporidiosis epidemiology in the United States.