1.   Most human infections are associated with exposure to aquatic environments or to recent consumption of seafood.

2.   New approaches need to be developed to contain this epizootic and prevent human infections.

3.   Potential sources of human infections change as society evolves.

4.   There are at least four species of which C parvum seems to be responsible for most human infection.

5.   But some epidemiologists have perceived a relaxed attitude toward the disease, and have warned that this could lead authorities to underestimate the risks of human infection.

6.   Health officials emphasized there still are no reported cases of human infection.

7.   However, such studies have limited value in predicting effectiveness in human infections.

8.   Human infections are rare but almost always fatal, according to the U.S. Centers for Disease Control and Prevention in Atlanta.

9.   Human infections or contaminated letters, however, can be confirmed through a battery of procedures that take several days to establish definitive proof.