Intestinal parasites remain extremely common worldwide. In developing count
ries, intestinal protozoans are important causes of childhood diarrhea. Cry
ptosporidiosis is a common cause of chronic diarrhea in patients with AIDS.
With the advent of current active antiretroviral therapy the incidence of
cryptosporidiosis in AIDS has decreased. By contrast, Cryptosporidium, Cycl
ospora, and Giardia outbreaks continue to be associated with contamination
of food or water. The intestinal helminths Ascaris, hookworm, and Trichuris
each infects over a thousand million people. While most of those infected
experience only minor symptoms, recent data highlight subtle effects of par
asitism on cognitive function and nutrition. Efforts at disease control in
developing countries are increasingly focused on mass chemotherapy. Curr Op
in Infect Dis 12:467-472. (C) 1999 Lippincott Williams & Wilkins.