10.

People With Severely
Weakened Immune System

 

 

v Guidance For People With Severely Weakened Immune Systems

Introduction

Cryptosporidium is a parasite commonly found in lakes and rivers, especially when the water is contaminated with sewage and animal wastes. Cryptosporidium is very resistant to disinfection, and even a well-operated water treatment system cannot ensure that drinking water will be completely free of this parasite. Current EPA drinking water standards were not explicitly designed to assure the removal or killing of Cryptosporidium. Many large water systems already voluntarily take actions for greater control of Crypto-sporidium and other microbial contaminants. By 2001, the water systems serving the majority of the United States population (those relying on a surface water source, such as a river, and serving more than 10,000 people) must meet a new EPA standard that strengthens control over microbial contaminants, including Cryptosporidium. EPA continues to conduct research on microbial contaminants which will be used for determining priorities for the drinking water program, including setting future standards and reevaluating existing standards.

Cryptosporidium has caused several large waterborne disease outbreaks of gastrointestinal illness, with symptoms that include diarrhea, nausea, and/or stomach cramps. People with severely weakened immune systems (that is, severely immunocompromised) are likely to have more severe and more persistent symptoms than healthy individuals. Moreover, Cryptosporidium has been a contributing cause of death in some immuno-compromised people. Individuals who are severely immunocompromised may include those who are infected with HIV/AIDS, cancer and transplant patients taking immunosuppressive drugs, and people born with a weakened immune system.

  Background

Data are not adequate to determine how most people become infected. For example, we do not know the importance of drinking water compared to other possible sources of Cryptosporidium, such as exposure to the feces of infected persons or animals, sex involving contact with feces, eating contaminated food, or accidentally swallowing contaminated recreational water.

Thus, in the absence of an outbreak, there are insufficient data to determine whether a severely immunocompromised individual is at a noticeably greater risk than the general public from waterborne Cryptosporidiosis. Even a low level of Cryptosporidium in water, however, may be of concern for the severely immuno-compromised, because the illness can be life-threatening. The risk of a severely immunocompromised individual acquiring Crypto-sporidiosis from drinking water in the absence of an outbreak is likely to vary from city to city, depending on the quality of the city's water source and the quality of water treatment. Current risk data are not adequate to support a recommendation that severely immunocompromised persons in all U.S. cities boil or avoid drinking tap water.

In the absence of a recognized outbreak, this guidance has been developed for severely immunocompromised people who may wish to take extra precautions to minimize their risk of infection from waterborne Cryptosporidiosis. To be effective, the guidance must be followed consistently for all water used for drinking or for mixing beverages. During outbreaks of waterborne Cryptos-poridiosis, studies have found that people who used precautions only part of the time were just as likely to become ill as people who did not use them at all. 

 

Guidance

EPA and CDC have developed the following guidance for severely immunocompromised people who may wish to take extra precautions. Such individuals should consult with their health care provider about what measures would be most appropriate and effective for reducing their overall risk of Cryptos-poridium and other types of infection.

Although data are not sufficient for EPA/CDC to recommend that all severely immunocompromised persons take extra caution with regards to their drinking water, individuals who wish to take extra measures to avoid waterborne Cryptospo-ridiosis can bring their drinking water to a full boil for one minute. Boiling water is the most effective way of killing Cryptosporidium.

As an alternative to boiling water, people may use the following measures:

u A point-of-use (personal use, end-of-tap, under-sink) filter. Only point-of-use filters that remove particles one micrometer or less in diameter should be considered. Filters in this category that provide the greatest assurance of Cryptos-poridium removal include those that use reverse osmosis, those labeled as "Absolute" one micrometer filters, or those labeled as certified by NSF International (National Sanitation Foundation) under standard 53 for "Cyst Removal." The "Nominal" one micrometer rating is not standardized and many filters in this category may not reliably remove Cryptosporidium. As with all filters, people should follow the manufacturer's instructions for filter use and replacement. Water treated with a point-of-use filter that meets the above criteria may not necessarily be free of organisms smaller than Cryptosporidium that could pose a health hazard for severely immunocompromised individuals.

u Bottled water. Many, but not all, brands of bottled water may provide a reasonable alternative to boiling tap water. The origin of the source water, the types of microorganisms in that water, and the treatment of that water before it is bottled vary considerably among bottled water companies and even among brands of water produced by the same company. Therefore, individuals should not presume that all bottled waters are absolutely free of Cryptosporidium. Bottled waters derived from protected well and protected spring water sources are less likely to be contaminated by Cryptosporidium than bottled waters containing municipal drinking water derived from less protected sources such as rivers and lakes. Any bottled water treated by distillation or reverse osmosis before bottling assures Cryptosporidium removal. Water passed through a commercial filter that meets the above criteria for a point-of-use device before bottling will provide nearly the same level of Cryptos-poridium removal as distillation or reverse osmosis. Bottled waters meeting the above criteria may not necessarily be free of organisms other than Cryptosporidium that could pose a health hazard for severely immunocompromised individuals.

Neither EPA nor CDC maintains a list of point-of-use filters or bottled water brands that meet the above criteria. NSF International can provide a list of filters that meet the NSF criteria. The NSF address is 3475 Plymouth Road, PO Box 130140, Ann Arbor, Michigan 48113-0140; phone number (877) 867-3435 (http://www.nsf.org/ ).

Individuals who contact bottlers or filter manufacturers for information should request data supporting claims that a brand of bottled water or filter can meet the above criteria.

Further Information

When an outbreak of waterborne Cryptosporidiosis is recognized and is determined to be on-going, officials of the public-health department and/or the water utility will normally issue a "boil water" notice to protect both the general public and the immunocompromised.

Current testing methods cannot determine with certainty whether Cryptosporidium detected in drinking water is alive or whether it can infect humans. In addition, the current method often requires several days to get results, by which time the tested water has already been used by the public and is no longer in the community's water pipes.

Severely immunocompromised people may face a variety of health risks. Depending on their illness and circumstances, a response by such individuals that focuses too specifically on one health risk may decrease the amount of attention that should be given to other risks. Health care providers can assist severely immunocompromised persons in weighing these risks and in applying this guidance.

 

 Source: Office of Water
U.S. Environmental Protection Agency
Centers for Disease Control and Prevention
http://www.epa.gov/safewater/crypto.html

  v Preventing Cryptosporidiosis: A Guide for People With Compromised Immune Systems

Who might be immunocompromised or have a weakened immune system?

Examples of persons with weakened immune systems include those with AIDS; cancer and transplant patients who are taking certain immunosuppressive drugs; and those with inherited diseases that affect the immune system. The risk of developing severe disease may differ depending on each person's degree of immune suppression. Following all the recommendations in this fact sheet can be a great personal burden, so consult with your health care provider to determine whether your medical condition makes it advisable to follow all of these recommendations. 

What is Cryptosporidiosis?

Cryptosporidiosis (krip-toe-spo-rid-e-o-sis), is a diarrheal disease caused by a microscopic parasite, Cryptosporidium parvum, that can live in the intestine of humans and animals and is passed in the stool of an infected person or animal. Both the disease and the parasite are also known as "Crypto." The parasite is protected by an outer shell that allows it to survive outside the body for long periods of time and makes it very resistant to chlorine disinfection. During the past 2 decades, Crypto has become recognized as one of the most common causes of waterborne disease (drinking water and recreational water) in humans in the United States. The parasite is found in every region of the United States and throughout the world.  

What are the symptoms of Crypto?

Symptoms include diarrhea, loose or watery stool, stomach cramps, upset stomach, and a slight fever. Some people have no symptoms.

How long after infection do symptoms appear?

Symptoms generally begin 2-10 days after being infected.

How long will symptoms last?

In persons with average immune systems, symptoms usually last about 2 weeks; the symptoms may go in cycles in which you may seem to get better for a few days, then feel worse before the illness ends.

How does Crypto affect you if your immune system is severely weakened?

In persons with AIDS and in others whose immune system is weakened, Crypto can be serious, long-lasting, and sometimes fatal. If your CD4+ cell count is below 200, Crypto is more likely to cause diarrhea and other symptoms for a long time. If your CD4+ count is above 200, your illness may not last more than 1 to 3 weeks or slightly longer. However, you could still carry the infection, which means that the Crypto parasites are living in your intestine, but are not causing illness. As a carrier of Crypto, you could infect other people. If your CD4+ count later drops below 200, your symptoms may reappear.

How is Crypto spread?

Crypto lives in the intestine of infected humans or animals. Millions of Crypto can be released in a bowel movement from an infected human or animal. You can become infected after accidentally swallowing the parasite. Crypto may be found in soil, food, water, or surfaces that have been contaminated with the feces from infected humans or animals. Crypto is not spread by contact with blood. Crypto can be spread:
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By putting something in your mouth or accidentally swallowing something that has come in contact with the stool of a person or animal infected with Crypto.

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By swallowing recreational water contaminated with Crypto. Recreational water is water in swimming pools, hot tubs, Jacuzzis, fountains, lakes, rivers, springs, ponds, or streams that can be contaminated with sewage or feces from humans or animals.

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By eating uncooked food contaminated with Crypto. Thoroughly wash with uncontaminated water all vegetables and fruits you plan to eat raw.

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By accidentally swallowing Crypto picked up from surfaces (such as toys, bathroom fixtures, changing tables, diaper pails) contaminated with stool from an infected person.

I have been diagnosed with Crypto. Should I worry about spreading infection to others?

Yes, Crypto can be very contagious. Follow these guidelines to avoid spreading Crypto to others.

Wash your hands with soap and water after using the toilet, changing diapers, and before eating or preparing food.

Avoid swimming in recreational water (pools, hot tubs, lakes or rivers, the ocean, etc.) if you have Crypto and for at least 2 weeks after diarrhea stops. You can pass Crypto in your stool and contaminate water for several weeks after your symptoms have ended. This has resulted in many outbreaks of Crypto among recreational water users. Note: You are not protected in a chlorinated pool because Crypto is chlorine resistant and can live for days in pools.

Avoid fecal exposure during sex.

What should I do if I think I have Crypto ?

See your health care provider.

How is a Crypto infection diagnosed?

Your health care provider will ask you to submit stool samples to see if you are infected. Because testing for Crypto can be difficult, you may be asked to submit several stool specimens over several days. Because tests for Crypto are not routinely done in most laboratories, your health care provider should specifically request testing for the parasite.

What is the treatment for Crypto?

There is no effective treatment. If you have diarrhea, drink plenty of fluids to prevent dehydration. Rapid loss of fluids because of diarrhea can be life-threatening in babies; parents should consult their health care provider about fluid replacement therapy options for babies. Antidiarrheal medicine may help slow down diarrhea, but consult with your health care provider before taking it.

People who are in poor health or who have a weakened immune system are at higher risk for more severe and more prolonged illness. For persons with AIDS, anti-retroviral therapy that improves immune status will also decrease or eliminate symptoms of Crypto infection. Some drugs, such as paromomycin, may reduce the symptoms of Crypto and new drugs are being tested. However, Crypto is usually not cured and may come back if the immune status worsens. See your health care provider to discuss anti-retroviral therapy used to improve immune status.

How can I protect myself from Crypto?

You can reduce your risk of getting Crypto. The more steps you take, the less likely you are to get infected. These actions will also help protect you against other diseases. Following all the recommendations in this fact sheet can be a great personal burden. Consult with your health care provider to determine whether your medical condition makes it advisable to follow all of these recommendations.

  1. Wash your hands.

Washing your hands often with soap and water is probably the single most important step you can take to prevent Crypto and other illnesses. Always wash your hands before eating and preparing food. Wash your hands well after touching children in diapers; after touching clothing, bedding, toilets, or bed pans soiled by someone who has diarrhea; after gardening; any time you touch pets or other animals; and after touching anything that might have had contact with even the smallest amounts of human or animal stool, including dirt in your garden and other places. Even if you wear gloves when you do these activities you should still wash well when you finish. Children should be supervised by adults to make sure they wash their hands well.

  1. Practice safer sex.

Infected people may have Crypto on their skin in the anal and genital areas, including the thighs and buttocks. However, since you cannot tell if someone has Crypto, you may want to take these precautions with any sex partner: "Rimming" (kissing or licking the anus) is so likely to spread infection that you should avoid it, even if you and your partner wash well before.Always wash your hands well after touching your partner's anus or rectal area.

  1.   Avoid touching farm animals.

If you touch a farm animal, particularly a calf, lamb, or other young animal, or visit a farm where animals are raised, wash your hands well with soap and water before preparing food or putting anything in your mouth. Do not touch the stool of any animal. After you visit a farm or other area with animals, have someone who is not immunocompromised clean your shoes, or wear disposable gloves if you clean them yourself. Wash your hands after taking off the gloves.

  1. Avoid touching the stool of pets.

Most pets are safe to own. However, someone who is not immunocompromised should clean their litter boxes or cages, and dispose of the stool. If you must clean up after a pet, use disposable gloves. Wash your hands afterwards. The risk of getting Crypto is greatest from pets that are less than 6 months old, animals that have diarrhea, and stray animals. Older animals can also have Crypto, but they are less likely to have it than younger animals. If you get a puppy or kitten that is less than 6 months old, have the animal tested for Crypto before bringing it home. If any pet gets diarrhea, have it tested for Crypto.

  1. Avoid swallowing water when swimming in the ocean, lakes, rivers, or pools, and when using hot tubs.

When swimming in lakes, rivers, or pools, and when using hot tubs, avoid swallowing water. Several outbreaks of Crypto have been traced to swallowing contaminated water while swimming. Crypto can live in chlorinated swimming pools and waterparks for days. Crypto also can remain alive in salt water for several days, so swimming in polluted ocean water may also be unsafe.

  1. Wash and/or cook your food.

Fresh vegetables and fruits may be contaminated with Crypto. Therefore, wash well all vegetables or fruit you will eat uncooked. If you take extra steps to make your water safe (see below for ways to do so), use this safe water to wash your fruits and vegetables. When you can, peel fruit that you will eat raw, after washing it. Do not eat or drink unpasteurized milk or dairy products. Cooking kills Crypto. Therefore, cooked food and heat-processed foods are probably safe if, after cooking or processing, they are not handled by someone infected with Crypto, or exposed to possibly contaminated water.

  1. Drink safe water.

Do not drink water directly from lakes, rivers, streams, or springs. Because you cannot be sure if your tap water contains Crypto, you may wish to avoid drinking tap water, including water or ice from a refrigerator, which is usually made with tap water. Because public water quality and treatment vary throughout the United States, always check with the local health department and water utility to see if they have issued any special notices about the use of tap water by immunocompromised persons. You may also wish to take some additional measures: boiling your water, filtering your water with certain home filters, or drinking certain types of bottled water. Processed carbonated (bubbly) drinks in cans or bottles are probably safe, but drinks made at a fountain might not be because they are made with tap water. If you choose to take these extra measures, use them all the time, not just at home. If the public health department advises boiling the water, do not drink tap water unless you boil it. You could also use one of the bottled waters described below.

  1. Boiling water: Boiling is the best extra measure to ensure that your water is free of Crypto and other germs. Heating water at a rolling boil for 1 minute kills Crypto, according to CDC and EPA scientists. After the boiled water cools, put it in a clean bottle or pitcher with a lid and store it in the refrigerator. Use the water for drinking, cooking, or making ice. Water bottles and ice trays should be cleaned with soap and water before use. Do not touch the inside of them after cleaning. If you can, clean water bottles and ice trays yourself.

  2. Filtering tap water: Not all available home water filters remove Crypto. All filters that have the words "reverse osmosis" on the label protect against Crypto. Some other types also work, but not all filters that are supposed to remove objects 1 micron or larger from water are the same. Look for the words "absolute 1 micron." Some "1 micron" and most "nominal 1 micron" filters will not work against Crypto. Also look for the words "Standard 53" and the words "cyst reduction" or "cyst removal" for an NSF-tested filter that works against Crypto.

To find out if a particular filter removes Crypto, contact NSF International (3475 Plymouth Road, P.O. Box 130140, Ann Arbor, MI 48113-0140, tel: 1-800-673-8010, fax: 1-313-769- 0109), an independent testing group. Ask NSF for a list of "Standard 53 Cyst Filters." Check the model number on the filter you intend to buy to make sure it is exactly the same as the number on the NSF list. Look for the NSF trademark on filters, but be aware that NSF tests filters for many different things. Because NSF testing is expensive, many filters that may work against Crypto have not been tested. Reverse-osmosis filters work against Crypto whether they have been tested by NSF or not. Many other filters not tested by NSF also work if they have an absolute pore size of 1 micron or smaller.

Filters designed to remove Crypto

(any of the four messages below on a package label indicate that the filter should be able to remove Crypto)
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Reverse-osmosis (with or without NSF testing)

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Absolute pore size of 1 micron or smaller (with or without NSF testing)

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Tested and certified by NSF Standard 53 for cyst removal

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Tested and certified by NSF Standard 53 for cyst reduction

Filters labeled only with these words may not be designed to remove Crypto
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Nominal pore size of 1 micron or smaller

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1-micron filter

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Effective against Giardia

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Effective against parasites

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Carbon filter

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Water purifier

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EPA approved - Caution: EPA does not approve or test filters.

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EPA registered - Caution: EPA does not register filters for Crypto removal

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Activated carbon

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Removes chlorine

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Ultraviolet light

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Pentiodide resins

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Water softener

Filters collect germs from your water, so someone who is not immuncompromised should change the filter cartridges for you; if you do it yourself, wear gloves and wash your hands afterwards. Filters may not remove Crypto as well as boiling does because even good brands of filters may sometimes have manufacturing flaws that allow small numbers of Crypto to get past the filter. Also, poor filter maintenance or failure to replace filter cartridges as recommended by the manufacturer can cause your filter to fail.

  1. Bottled water: If you drink bottled water, read the label and look for this information:

 

Water so labeled has processed by method effective against by Crypto Water so labeled may not been processed by method effective against Crypto
Reverse-osmosis treated 

Distilled 

Filtered through an absolute 1 micron or smaller filter

"1-micron absolute" 

 

 Filtered
Micro-filtered
Carbon-filtered
Particle-filtered
Multimedia-filtered
Ozonated
Ozone-treated
Ultraviolet light-treated
Activated carbon-treated
Carbon dioxide-treated
Ion exchange-treated
Deionized
Purified
Chlorinated

Bottled water labels reading "well water," "artesian well water," "spring water," or "mineral water" do not guarantee that the water does not contain Crypto. However, water that comes from protected well or protected spring water sources is less likely to contain Crypto than bottled water or tap water from less protected sources, such as rivers and lakes. Any bottled water (no matter what the source) that has been treated by one or more of the methods listed in the top part of the water filters table is considered safe.

  1. Home distillers: You can remove Crypto and other germs from your water with a home distiller. If you use one, you need to carefully store your water as recommended for storing boiled water.

  2. Other drinks: Soft drinks and other beverages may or may not contain Crypto. You need to know how they were prepared to know if they might contain Crypto.


If you drink prepared drinks, look for drinks prepared to remove Crypto:

  Information on Prepared Drinks

 

Crypto killed or removed in preparation   Crypto may not be killed or removed in preparation
Canned or bottled soda, seltzer, and fruit drinks

Steaming hot (175 degrees F or hotter) tea or coffee

Pasteurized drinks

 Fountain drinks 

Fruit drinks you mix with tap water from frozen concentrate

Iced tea or coffee

Juices made from fresh fruit can also be contaminated with Crypto. Several people became ill after drinking apple cider made from apples contaminated with Crypto. You may wish to avoid unpasteurized juices or fresh juices if you do not know how they were prepared.

  1. Take extra care when traveling.

If you travel to developing nations, you may be at a greater risk for Crypto because of poorer water treatment and food sanitation. Warnings about food, drinks, and swimming are even more important when visiting developing countries. Avoid foods and drinks, in particular raw fruits and vegetables, tap water, or ice made from tap water, unpasteurized milk or dairy products, and items purchased from street vendors. These items may be contaminated with Crypto. Steaming-hot foods, fruits you peel yourself, bottled and canned processed drinks, and hot coffee or tea areprobably safe. Talk with your health care provider about other guidelines for travel abroad.

 For more information on Crypto, call the CDC National HIV and AIDS Hotline at 1-800-342-AIDS.

This information was prepared by the inter-agency Working Group on Waterborne Cryptosporidiosis, which includes representatives from the Centers for Disease Control and Prevention, Environmental Protection Agency, Food and Drug Administration, U.S. Department of Agriculture, National Association of People With AIDS, AIDS Coalition to Unleash Power, and representatives of state and local health departments and water utilities.

 This fact sheet is for information only and is not meant to be used for self-diagnosis or as a substitute for consultation with a health care provider. If you have any questions about the disease described above or think that you may have a parasitic infection, consult a health care provider.