Environmental Engineering Reference
In-Depth Information
Type I
meront
Sporozoite
Trophozoite
Host
epithelial cell
Excystation
Ingestion
Auto
infection
Merozoite
ick-walled
oocysts
in-walled
oocysts
Exit from
body
Microgamont
Merozoite
Type II
meront
Mature
oocyst
Immature
oocyst
Macrogamont
Figure 6.5
Life cycle of
Cryptosporidium parvum
.
genus began to be felt in the medical community when Slavin (1955) wrote
about a new species,
Cryptosporidium meleagridis
, which was associated with
illness and death in turkeys. Interest remained slight, though, even when
Cryptosporidium
was found to be associated with bovine diarrhea (Panciera
et al., 1971).
Not until 1982 did worldwide interest focus in on the study of organisms
in the genus
Cryptosporidium
. At that time, the medical community and other
interested parties were undertaking a full-scale, frantic effort to find out
as much as possible about acquired immune deficiency syndrome (AIDS).
The CDC reported that 21 AIDS-infected males from six large cities in the
United States had severe protracted diarrhea caused by
Cryptosporidium
. It
was in 1993, though, that
Cryptosporidium
—the “pernicious parasite”—made
Milwaukee famous (Mayo Foundation, 1996).
Note:
The
Cryptosporidium
outbreak in Milwaukee caused the deaths
of 100 people—the largest U.S. episode of waterborne disease in the 70
years since health officials began tracking such outbreaks.
