Cryptosporidiosis
(crip-toe-spor-id-i-o-sis)
Information for People with Weakened Immune Systems
What is cryptosporidiosis?
Cryptosporidiosis is an intestinal illness caused by a microscopic
parasite called Cryptosporidium.
Is cryptosporidiosis a new disease?
Although Cryptosporidium is not new, it was not recognized as a cause
of human disease until 1976. Cryptosporidiosis was added to the list
of reportable diseases in New York State in February 1994.
How common is cryptosporidiosis?
The number of cryptosporidiosis cases that occur each year is not
yet well documented. Since the disease has recently been added to the
list of reportable diseases, state and county health departments are
now beginning to record the number and location of identified cases
so that public health control measures can be developed. In 1994, 302
cases were reported to the New York State Department of Health. However,
more cases may have occurred that were not detected, either because
the Cryptosporidium stool test may not have been requested by the health
care provider or the laboratory may have failed to use the necessary
tests to identify it.
What are the symptoms of cryptosporidiosis?
The most common symptom is diarrhea which is usually watery. It is
often accompanied by abdominal cramping. Nausea, vomiting, fever, headache
and loss of appetite may also occur. Some people infected with Cryptosporidium
may not become ill.
Who is susceptible to cryptosporidiosis and how long does the illness
last?
All people are presumed susceptible to infection with Cryptosporidium.
In healthy individuals with normal immune systems, signs and symptoms
generally persist for two weeks or less. However, immunocompromised
persons (those with weak immune systems) may have severe and long lasting
illness. Some examples of immunocompromised people are those receiving
cancer chemotherapy, kidney dialysis, steroid therapy, people with HIV/AIDS
and patients with Crohnıs disease.
How long after exposure do symptoms appear?
The incubation period may range from one to 12 days with an average
of seven days.
How is the disease contracted?
Cryptosporidium is shed in the feces of infected humans and animals.
People become infected by ingesting the organism. Cryptosporidium can
be spread by person-to-person or animal-to-person contact and by drinking
contaminated water. Infected individuals can shed the organism in their
stool for several weeks after they recover from the illness. Because
cryptosporidiosis is transmitted by the fecal-oral route, the greatest
potential to transmit the organism comes from infected people who have
diarrhea, people with poor personal hygiene and diapered children.
Does past infection with cryptosporidium make a person immune?
Some immunity appears to follow infection but the degree to which
a previously infected person is immune to subsequent Cryptosporidium
infection is unclear. Exposure to a large dose of the parasite could
result in recurrent illness.
How is cryptosporidiosis diagnosed?
The infection is diagnosed by identifying the parasite during a microscopic
examination of the stool. When a person with diarrheal illness is suspected
of having cryptosporidiosis, the health practitioner should specifically
request a Cryptosporidium test, since most laboratories do not yet routinely
perform the necessary tests needed to identify this particular microscopic
parasite. A cryptosporidium test should specifically be ordered for
people with HIV/AIDS or other immunocompromised patients (for example,cancer
or transplant patients) who are being treated for diarrhea.
How is cryptosporidiosis treated?
There is no specific treatment for cryptosporidiosis. However, some
patients may respond to certain antibiotics. Oral liquids or intravenous
fluids are sometimes necessary if dehydration occurs. Anti-diarrheal
drugs which reduce the motion of the intestines may provide some temporary
improvement. Patients with cryptosporidiosis should obtain nutritional
counseling through their health care provider to discuss their diet
and how best to minimize the symptoms of their diarrhea.
How can I avoid getting and transmitting cryptosporidiosis?
You can minimize the chances of acquiring and spreading the infection
by thoroughly washing your hands after using the toilet, changing diapers
or coming into contact with fecal material in any way. Because cattle
are a common source of Cryptosporidium, do not drink raw milk and be
sure to wash your hands thoroughly after contact with cattle or other
farm animals. Avoid drinking untreated and inadequately filtered surface
water when camping or when traveling in developing countries. Comply
with any water advisory issued by local and state authorities.
Has Cryptosporidium been found in New York State water systems and is
it easily detectable?
It is believed that Cryptosporidium has always been present to some
degree in water. Recently, it has been found in low numbers in some
drinking waters derived from surface water sources (streams, lakes or
reservoirs) in New York State and across the nation. There have been
no waterborne outbreaks of cryptosporidiosis identified in New York
State. Only laboratories with specialized testing capabilities can detect
the presence of Cryptosporidium cysts in water. Laboratory tests are
not very reliable at this time and they cannot tell whether the cyst
is alive or dead.
Should immunocompromised persons take extra precautions to minimize their
risk of cryptosporidiosis?
Because cryptosporidiosis can be a severe disease in immunocompromised
persons, such individuals should discuss the need for extra precautions
with their health care provider to minimize their risk of infection.
Contaminated drinking water is only one of a number of ways in which
cryptosporidiosis can be acquired. Here are some suggested steps to
reduce risk of infection:
- Wash hands thoroughly after changing diapers or whenever fecal soiling
occurs.
- Avoid sexual practices that may result in hand or mouth exposure
to feces, such as oral/anal contact (rimming).
- Avoid direct exposure to cattle and other farm animals. If exposure
cannot be avoided, wash your hands thoroughly immediately thereafter.
- Avoid swallowing water when swimming, especially in lakes, ponds
or rivers. There has been one documented case of Cryptosporidium transmitted
to a number of people who swam in a recreational wave pool and apparently
swallowed the water.
- Thoroughly wash all fruits and vegetables. Avoid drinking unpasteurized
apple cider, since there has been a documented incident of Cryptosporidium
transmitted through fresh cider made from apples gathered in a field
in which cows were grazing.
If an outbreak of waterborne Cryptosporidium is identified (none has been
to date in New York), immunocompromised patients should carefully and
consistently comply with all public advisories and notices issued by the
local or state health department. The four items listed below may help
immunocompromised patients and their health care providers decide whether
to take extra routine precautions with drinking water under normal, nonoutbreak
conditions:
- Boiling water for at least one minute with a rolling boil will
kill Cryptosporidium.
- Properly drilled and maintained wells that utilize underground
water are generally protected from surface contamination and are unlikely
to contain Cryptosporidium cysts.
- Unless it is distilled or pasteurized, bottled water may not be
any safer than tap water. Those bottling companies using properly
designed and operated groundwater sources have a very low likelihood
of producing water containing Cryptosporidium cysts. Those companies
using surface water sources have the same risk of cryptosporidiosis
as tap water from the same source unless additional treatment is undertaken.
Current standards for bottled water do not guarantee that the water
is Cryptosporidium free. Bottled water sold in New York must also
include on the label whether the water comes from a well, spring or
municipal source. A list of bottled waters certified for sale in New
York along with their sources can be obtained from the New York State
Department of Health at 1-800-458-1158.
- During an outbreak of cryptosporidiosis in Milwaukee in 1993, one
study showed that less diarrhea occurred in houses using water filters
with a pore size less than 2 microns as compared to others using filters
with large pore sizes. If home water filters are used, follow the
manufacturerıs instructions supplied with the unit. The instructions
will provide information on filter maintenance needed to prevent clogging
and ensure proper filtration. Filters should be certified by the National
Sanitation Foundation (NSF) or an equivalent testing agency for cyst
removal.
For additional information, contact your health care provider or your
local or state health department.
Updated: April 1996
Source: NY State Department of Health
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