Biology Reference
In-Depth Information
Figure 2.8
Image of
Entamoeba
, compared to
Cryptosporidium
and
Giardia
. Source:
Reproduced from Ref.
38
.
(For color version of this figure, the reader is referred to the
online version of this topic.)
with a higher incidence in tropical and subtropical regions. In contrast,
amoebic encephalitides is far rarer, with only 500 cases reported worldwide
between 1960 and 2000.
38
2.3.4.
Giardia
Giardia lamblia
(
G. lamblia
) (also known as
Giardia intenstinalis
or
Giardia
duodenalis
) contaminates water supplies across the globe, and ingestion of its
cysts can cause giardiasis,
39
an acute self-limiting gastroenteritis. This species
is the only one in the genus associated with human infection (
Fig. 2.9
). Like
Cryptosporidium
,
G. lamblia
has a low infectious dose (1-10 cysts)
40
and those
most at risk are the young or immunocompromised.
41
Treatment of giar-
diasis varies depending on the patient, as does the effectiveness of different
drugs, the side effects of which are very common.
42
This pathogen causes
a major problem for the water industry as it is resistant to disinfection by
chlorine treatment
43
and it can also pass with up to 30% efficiency through
more advanced membrane filters.
44
Search WWH ::
Custom Search