One obstacle is that the diseases, long thought to be an overseas problem, are only briefly discussed in most U.S. medical school classes and textbooks, so many physicians don't recognize them.
Some of the infections are transmitted by bug bites and some by animal feces contaminated with parasite larvae; still others are viral. All spread in conditions of overcrowding, malnutrition, poor sanitation and close contact with animals receiving little veterinary care.
"These are diseases that we know are ten-fold more important than swine flu," said Peter Hotez, a microbiologist at George Washington University and leading researcher in this field. "They're on no one's radar."
