[at-l] Giardia and Cryptosporidium

[nealb@midlandstech.com (William Neal)]

After seeing all the messages about the dangers or non-dangers of GIARDIA, I
decided to do a bit of researching.  I found a lot, but most of it is good.
Either it came from Government sources - I guess some of us will distrust it
since it's from the "Gub-er-mint" - and some of it was from outdoor related
sites (I'm too lazy to quote from books).  So I cut, pasted, and edited some
of the most interesting facts.  If there is anything wrong with it, blame my
10 thumbs - maybe that's why at my age, I can't keep my shoes tied.  Anyway
if you are still interested in the facts about Giardia, below is some of the
facts.  Sorry it's so long.


Giardia and Cryptosporidium

Giardia lamblia and Cryptosporidium parvum are protozoan parasites,
infecting the digestive tract of man and other warm blooded animals.  It has
been demonstrated that semi-aquatic mammals  can serve as a host,
transmitting the disease to humans who consume contaminated water.
Domestic mammals can serve as a host of Cryptosporidium, and, as in Giardia,
the animal can contaminate a drinking water supply.  Research has also shown
that both Giardia and Cryptosporidium are highly resistant to chlorine, a
commonly used water disinfectant.  Due to the small size of Giardia cysts
and Cryptosporidium oocysts (8 to 12 microns and 4 to 5 microns,
respectively), both are difficult to remove through filtration.  >>> I think
they are referring to ordinary filters & not the kind usually carried by
backpackers.<<< It is currently believed that approximately 7% of the
diarrhea cases in the United States are caused by Cryptosporidium.  This
figure may be misleading, as causes of diarrhea are seldom tested for by
physicians. Cryptosporidiosis can be fatal to immuno-compromised patients.  
>From   http://www.state.me.us/dhs/eng/water/giarcryp.htm
<http://www.state.me.us/dhs/eng/water/giarcryp.htm> 
  _____  

Giardia duodenalis, cause of giardiasis (GEE-are-DYE-uh-sis), is a
one-celled, microscopic parasite that can live in the intestines of animals
and people. It is found in every region throughout the world and has become
recognized as one of the most common causes of waterborne (and occasionally
foodborne) illness.
 
About 40% of those who are diagnosed with giardiasis demonstrate
disaccharide intolerance during detectable infection and up to 6 months
after the infection can no longer be detected. Lactose (i.e., milk sugar)
intolerance is most frequently observed. Some individuals (less than 4%)
remain symptomatic more than 2 weeks; chronic infections lead to a
malabsorption syndrome and severe weight loss. Chronic cases of giardiasis
in immunodeficient and normal individuals are frequently refractile to drug
treatment. In some immune deficient individuals, giardiasis may contribute
to a shortening of the life span.
 
Clinically, Giardia produces a broad spectrum of gastrointestinal symptoms,
including one or more of the following symptoms: diarrhea, flatulence,
bloating, weight loss, abdominal cramping, nausea, malabsorption,
foul-smelling stools, steatorrhea, fatigue, anorexia, and chills. Although
the hallmark of giardiasis is diarrhea, asymptomatic infections can occur
(15,16), especially in children and in persons with prior infections (6).
Giardia cysts can be excreted in the stool intermittently for weeks or
months, resulting in a protracted period of communicability (14,17,18). 
 
Avoid swallowing recreational water (e.g., water in lakes, rivers, swimming
pools, water parks). 
Avoid drinking untreated water from shallow wells, lakes, rivers, springs,
ponds, and streams. 
Avoid drinking untreated water during communitywide outbreaks caused by
contaminated drinking water. 
Avoid drinking untreated water when traveling in countries where the water
supply might be unsafe. 
If you are unable to avoid water that might be contaminated, then treat the
water. 
Heat water to a rolling boil for 1 minute.  Or Use a filter that has an
absolute pore size of at least 1µm or that has been NSF-rated for cyst
removal. 
Do not rely on cyst inactivation by chlorination or iodination, which are
less effective than other methods because they are highly dependent on the
temperature, pH, and cloudiness of the water.
>From CDC's MORTALITY & MORBIDITY WEEKLY REPORT
>>> One of my favorite journals - just for the name.  <<<
 
How long can an infected person carry giardia? 
The carrier stage generally lasts from a few weeks to a few months.
Treatment with specific antibiotics may shorten the carrier stage. 
  _____  

Where are the giardia parasites found? 
Giardia has been found in infected people (with or without symptoms) and
wild and domestic animals. The beaver has gained attention as a potential
source of giardia contamination of lakes, reservoirs and streams, but human
fecal wastes are probably as important. 
  _____  

Should an infected person be excluded from work or school? 
People with active diarrhea who are unable to control their bowel habits
(infants, young children, certain handicapped individuals, for example) may
need to be excluded from settings such as day care or group activities where
they may present a risk to others. After they have been treated and have
recovered, they may be permitted to return. In addition, some local health
departments may require follow-up stool testing to confirm that the person
is no longer contagious. Individuals who are not in high-risk settings may
return to their routine activities when they have recovered, provided that
they carefully wash their hands after each toilet visit. 
  _____  


New York State Department of Health
Communicable Disease Fact Sheet

  _____  

Over the last 25 years a trend has grown through the backcountry of the
United States. Giardia lamblia, an amoeba like protozoa has been spreading
into streams, rivers and lakes. Found in two forms, both as an active
trophozoite and as a dormant cyst, Giardia is responsible for making tens of
thousands of people sick each year in the United States. The good news is
that a run in with Giardia in developed areas of the world isn't going to be
fatal as long as you are in good health and have access to medical
treatment. In more remote sections of Asia, Africa, and Latin America,
Giardia is responsible for over two million infections annually and
thousands of deaths, sadly most of these are children. 

Boiling your water before drinking it is sound advice. Just getting the
water to a boil will kill off most nasty stuff, including Giardia. However
there are hardier species of viruses and bacteria that can survive even at
high temperatures. To be safe make sure you boil your water for at least
five minutes. Boiling water isn't just good advice, it is also the cheapest
way to remove biological pathogens from water. One thing that boiling will
not do is remove chemical contaminates. If your water source is cloudy and
or devoid of any life (fish, plants, algae, frogs or other amphibians, etc.)
it might not be safe to drink regardless of how long you boil it. 
 
The main issue with chemical treatments is the water needs to be warm, at
least 70 degrees to be effective. Cold water may need treatment all night to
be safe. People who have thyroid problems can have serious medical issues
with ingesting iodine, and prolonged exposure to iodine has been known to
cause thyroid problems.
 
This leads to the third solution, which is filtering. Filters come in all
sorts of shapes, sizes, and capacities (we could write a whole story just on
filters). Filters can offer three different options, a simple
microbiological filter with pores measured in microns, a carbon filter
system as well as pores, and/or an iodine filtering system as well as the
pores. If you have a filter or are looking to buy one, don't waste your
money on anything that has filter pores larger than 0.2 microns. Anything
larger and bacteria can still pass through, however the much larger Giardia
cysts and protozoa will still be filtered out. A filter without iodine will
not remove viruses, so in the end you may have to boil your water anyway or
treat with iodine. A filter with carbon or charcoal has a major advantage
over the other purifying methods; it can remove dangerous chemicals from the
water that tablets and boiling will leave behind. Another benefit of
filtering is the water will usually taste better. 
One thing to keep in mind if you are boiling, using tablets, and not using a
charcoal filter is they will not take chemical contaminates out of the
water. Arsenic, lead, and other heavy metals, dangerous amounts of
potassium, phosphorus, and heavy sediments will all be left behind. In
certain places like Badlands National Park in South Dakota no amount of
treatment, short of dragging a reverse osmosis plant with you is going to
make the water potable. In areas where there is a lot of agriculture
activity and leeching from fertilizers this can be especially dangerous. The
bottom line, know your water source as best as you can. 
http://www.outdoorplaces.com/Features/Backcountry/giardia/
<http://www.outdoorplaces.com/Features/Backcountry/giardia/> 
OUTDOOR PLACES.COM
  _____  

>From now on I'm NUKING the water.  At least I won't have to worry about a
flashlight if I do.
William, The Overly Curious Turtle


--- StripMime Report -- processed MIME parts ---
multipart/alternative
  text/plain (text body -- kept)
  text/html
---