Controlling Spread of Giardiasis

Table of Contents

A. Isolation and Quarantine Requirements

Food handlers with giardiasis must be excluded from work until diarrhea has ceased.

B. Protection of Contacts of a Case

 None.

C. Managing Special Situations

Child care

Since giardiasis may be transmitted person-to-person through fecal-oral transmission, it is important to carefully follow up on cases of giardiasis in child care settings.

  • Children with giardiasis who have diarrhea should be excluded until their diarrhea is gone.
  • Children with giardiasis who have no diarrhea and are otherwise not ill may be excluded or can remain in the program if special precautions are taken.
  • Since most staff in child-care programs are considered food handlers, those with Giardia in their stools who are symptomatic should not be at work until diarrhea has ceased.  When returning to work good hand hygiene should be practiced at all times.
  • All child care staff and children should practice good hand hygiene at all times.

School

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

  • Students or staff with giardiasis who have diarrhea should be excluded until their diarrhea is gone.
  • Students or staff with giardiasis, who do not handle food, have no diarrhea and are not otherwise sick, may remain in school if special precautions are taken. Students and staff must practice frequent and thorough handwashing using warm running water, soap, with friction for at least 15 seconds, and thoroughly drying their hands with paper towels or a blow dryer.  If symptoms of giardiasis occur the person should be excluded.

Food Handler

Note: A food handler is any person directly preparing or handling food. This can include a patient care or child-care provider. See glossary for a more complete definition.

Since Giardia may be transmitted via food, it is important to follow up on outbreaks of Giardia in any setting carefully.  General recommendations include:

  • Food handlers with Giardia infection who have diarrhea should be excluded until their diarrhea is gone, (until 24 hours after last bout of diarrhea or until formed stools are occurring).
  • Food handlers must practice frequent and thorough handwashing using warm running water and soap, with friction for at least 15 seconds, and thoroughly dry their hands with paper towels or a blow dryer.

Community Residential Programs

Actions taken in response to a case of giardiasis in a community residential program will depend on the type of program and the level of functioning of the residents. In long-term care facilities, residents with giardiasis should be placed on standard (including enteric) precautions until their symptoms subside. Staff members who give direct patient care (e.g., feed patients, give mouth or denture care or give medications) are considered food handlers and are subject to food handler restrictions. In residential facilities for the developmentally disabled, staff and clients with giardiasis must refrain from handling or preparing food for other residents until their diarrhea has subsided.

Reported Incidence Is Higher than Usual or an Outbreak is Suspected

If the number of reported cases of giardiasis in your city or county is higher than usual, or if an outbreak is suspected, 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 (e.g., removing an implicated food item from the environment). Control of person-to-person transmission requires special emphasis on personal cleanliness and sanitary disposal of feces. Consult with CADE at (800)-362-2736. CADE can help to determine a course of action to prevent further cases and can perform surveillance for cases in an outbreak that may cross several county lines and therefore be difficult to identify at a local level.

D. Preventive Measures

Environmental Measures

To avoid exposure, recommend that individuals:

  • Always wash their hands thoroughly with soap, water, and friction for at least 15 seconds before eating or preparing food, after using the toilet and after changing diapers.
  • In child cares, dispose of feces in a sanitary manner.
  • When caring for someone with diarrhea, scrub hands with plenty of soap and water after cleaning the bathroom, helping the person use the toilet, or changing diapers, soiled clothes, or soiled sheets.
  • When hiking or camping, be aware of the risks of drinking water from streams or lakes. Bringing water to a full, rolling boil is sufficient to kill Giardia. Several filters are also available that remove Giardia cysts. Additionally, some chemical water treatments are effective against Giardia.
  • Avoid sexual practices that may involve direct contact with feces. Latex barrier protection should be emphasized as a way to prevent the spread of Giardia to case’s sexual partners as well as being a way to prevent the exposure to and transmission of other pathogens.

International Travel

Travelers to developing countries should:

  • “Boil it, cook it, peel it, or forget it." 
  • Drink only bottled or boiled water, keeping in mind that bottled carbonated water is safer than uncarbonated water.
  • Ask for drinks without ice unless the ice is made from bottled or boiled water. Avoid popsicles and flavored ices that may have been made with contaminated water.
  • Eat foods that have been thoroughly cooked and are still hot and steaming.
  • Avoid raw vegetables and fruits that cannot be peeled. Vegetables like lettuce are easily contaminated and are very hard to wash well.
  • Peel their own raw fruits or vegetables and do not eat the peelings.
  • Avoid foods and beverages from street vendors.

Note: For more information regarding international travel, contact the CDC’s Traveler’s Health Office at (877) 394-8747 or visit: www.cdc.gov/travel