Controlling Spread of Cryptosporidiosis

Table of Contents

A. Isolation and Quarantine Requirements

In health care settings Standard Precautions should be used. Use Contact Precautions for diapered or incontinent persons for the duration of illness or to control institutional outbreaks. 

B. Managing Special Situations

Child Care

Since cryptosporidiosis may be transmitted person-to-person through fecal-oral transmission, it is important to follow up on outbreaks of cryptosporidiosis in a child care setting.  General recommendations include:

  • Children with Cryptosporidium who have diarrhea should be excluded until their diarrhea is resolved. Children are not required to provide two negative stools to return to child care. 
  • Children with Cryptosporidium who have no diarrhea and are not otherwise ill may remain in the program if special precautions are taken. (Proper hand-washing practices, separation of diapering and food preparation areas, excluding if symptoms should occur.)

Schools

Since cryptosporidiosis may be transmitted person-to-person through fecal-oral transmission, it is important to follow up on suspected outbreaks of cryptosporidiosis in a school setting carefully.  General recommendations include:

  • Students or staff with Cryptosporidium who have diarrhea should be excluded until the diarrhea is resolved.
  • Students or staff with Cryptosporidium who do not handle food, have mild or no diarrhea and are not otherwise sick may remain in school if special precautions are taken. (Proper hand-washing practices, separation of diapering and food preparation area, excluding if symptoms should occur.)

Food Handler

Note: A food handler is any person directly preparing or handling food, including a patient care or child care provider.

Since Cryptosporidium can be transmitted person-to-person through fecal-oral contact, it is important to carefully follow up on outbreaks of Cryptosporidium in any setting.  General recommendations include:

  • Food handlers with Cryptosporidium infection who have diarrhea should be excluded until 24 hours after last bout of diarrhea, or until stools are formed.

  • Food handlers must practice frequent and thorough handwashing, using warm, running water, soap with friction for at least 15 seconds, and thoroughly drying hands with paper towels or a blow dryer.

Swimming Pools

In recent years, outbreaks from community swimming pools have become more frequent, especially in the summer months. The increased availability of shallow water for infants and toddlers (diaper-age children) may be a major reason for these outbreaks. Normal chlorination (1-8 ppm) will not destroy Cryptosporidium oocysts. All cases should be counseled not to swim for 2 weeks after resolution of diarrhea. This is due to the low infectious dose and hardy nature of Cryptosporidium oocysts, which are resistant to chlorine. 

Signs should be posted prominently at all swimming venues directing that anyone who has a diarrheal illness should not use a public pool. Careful attention should be given to children in diapers so that “fecal accidents” do not contaminate a swimming or wading pool. Diaper-age children should always wear swim diapers to help prevent swimming pool water contamination by gross fecal material. Children in diapers should not have contact with public swimming or wading pool water if they have a diarrheal illness.   Caregivers should not change diapers on the deck of a swimming pool; most newer facilities have diaper changing areas within the bathhouse. Dirty diapers should be disposed of in a sanitary fashion (never rinsed in pool water). Caregivers should thoroughly wash their hands and those of the child after changing a diaper.

Swimming pool inspections in most counties are done by a city, county or regional environmental health agency. If a sporadic case or an outbreak of Cryptosporidium occurs and is thought to be related to a swimming pool, wading pool, spray/splash pad, or spa exposure, the responsible environmental health agency should be notified (refer to the Pool Inspection Contractor Contact List) so that an exposure risk assessment can be conducted and action can be taken to prevent further exposure at that site. Include the number of suspect and confirmed cases linked to the implicated site and the date potential exposure began (12 days before symptom onset of earliest case) when notifying the environmental health agency.

If public health and environmental health officials recommend superchlorination (refer to the CDC Fecal Accident Response Recommendations) of a pool, the superchlorination should be done to minimize the time the pool facility is closed. Closing a facility to superchlorinate may move users to other facilities nearby. Public health and environmental health officials should consider a recommendation that nearby swimming facilities also superchlorinate as a precaution against further transmission of Cryptosporidium.

Community Residential Programs

Actions taken in response to an outbreak of cryptosporidiosis in community residential programs will depend on the type of program and the level of functioning of the residents.

In long-term care facilities, residents with cryptosporidiosis should be placed on standard precautions until symptoms subside. Contact Precautions should be used for diapered or incontinent persons for the duration of illness or to control institutional outbreaks. Staff members with Cryptosporidium infection should not work until diarrhea is gone.

In residential facilities for the developmentally disabled, staff and clients with cryptosporidiosis must refrain from handling or preparing food for other residents until diarrhea has subsided.  Staff members with cryptosporidiosis who are not food handlers should not work until diarrhea is gone.

C. Reported Incidence Higher than Usual/Community Outbreak Suspected

If the number of reported cases of cryptosporidiosis in your city or county is higher than usual, or if you suspect an outbreak, investigate to determine the source of infection and mode of transmission. A common vehicle (such as water, food, or association with a child care center) should be sought and applicable preventive or control measures should be instituted. Control of person-to-person transmission requires special emphasis on personal hygiene and sanitary disposal of feces. Consult with the CADE (800-362-2736) for assistance with investigation and control. 

D. Preventive Measures

Personal Preventive Measures/Education

All cases regardless of whether or not they received treatment should be counseled not to swim for 2 weeks after resolution of diarrhea. This is due to the low infectious dose and hardy nature of Cryptosporidium oocysts, which are resistant to chlorine.  Children in diapers should not have contact with public swimming or wading pool water if they have a diarrheal illness.  

To avoid exposure, recommend that individuals:

  • Always wash hands thoroughly with soap and water before handling food or eating, after using the toilet or changing diapers, and after contact with animals, especially cattle.
  • Wash the child’s hands and their own after changing diapers.
  • Avoid drinking raw milk, other unpasteurized dairy products, or unpasteurized juices.
  • Wash all raw fruits and vegetables before serving.
  • Dispose of feces in a sanitary manner, especially in child care centers or other institutional settings.
  • Avoid drinking water from streams or lakes. Avoid drinking unboiled water while traveling in developing countries or whenever water quality is unknown. (Bringing water to a full, rolling boil is sufficient to kill Cryptosporidium, or use filters capable of removing particles 0.1-1.0 micrometers in diameter.)
  • Adhere to local advisories to boil water.
  • Avoid swallowing water when swimming.  Lakes, streams, other surface waters and swimming pools may be contaminated with Cryptosporidium.  Chlorination does not effectively eliminate the parasite.

It is unlikely that Cryptosporidium could cause illness in regulated, public drinking water, but immunocompromised individuals may want to consider the following recommendations:

  • Boil tap water before drinking or making ice cubes.
  • Consider the use of a home water filtering system with a very fine filter (absolute pore size of 1 micron or smaller). Such filters include reverse-osmosis filters; filters labeled “absolute” 1 micron; and those labeled as meeting National Sanitation Foundation (NSF) standard #53 for cyst removal.
  • Avoid fecal contact.
  • Avoid sexual practices that may involve direct contact with feces. Latex barrier protection should be used to prevent the spread of Cryptosporidium and exposure to and transmission of other pathogens to case’s sexual partners.

Iowa Dept. of Public Health, Revised  7/15