Drinking Water
In certain situations, such as international travel or backcountry travel, you may not be sure if the water you use or drink contains Cryptosporidium parasites (also known as Crypto). For people with weakened immune systems, this uncertainty may be of greater concern. To avoid drinking water that might be contaminated with Crypto:
- Do not swallow recreational water. See the Healthy Swimming Web site.
- Do not drink untreated water from shallow wells, lakes, rivers, springs, ponds, and streams.
- Do not drink untreated tap water during community-wide outbreaks of disease caused by contaminated drinking water.
- Do not drink tap water that has not been boiled or ice that has not been made from boiled water when the public health department advises boiling the water (boil water advisory). See Boil Water Advisories.
- Do not use or consume untreated ice or drinking water when traveling in countries where the water supply might be unsafe. See Travelers.
If you are unable to avoid using or drinking water that might be contaminated, then you can treat the water for Crypto using one of the following methods:
- Boiling it at a rolling boil for 1 minute (at altitudes greater than 6,562 feet (>2,000 m), boil water for 3 minutes).
- Filtering it using a filter with an absolute pore size of 1 micron or smaller, or one that has been NSF rated for “cyst removal”. For more information about filters, visit A Guide to Water Filters.
- Distilling it using a home distiller. If you use one, you need to carefully store your water. After purification, put the water in a clean bottle or pitcher with a lid and store it in the refrigerator. Water bottles and ice trays should be cleaned with soap and water before use – do not touch the inside of them after cleaning.
Do not rely on chemicals to disinfect water and kill Cryptosporidium. Because it has a thick outer shell, this particular parasite is highly resistant to disinfectants such as chlorine and iodine.
You can also use commercially-bottled water. Alternatively, in the United States, nationally distributed brands of bottled or canned carbonated soft drinks are safe to drink. Commercially packaged non-carbonated soft drinks and fruit juices that do not require refrigeration until after they are opened (those that are stored unrefrigerated on grocery shelves) also are safe.
Related Drinking Water Links
A Guide to Commercially-Bottled Water and Other Beverages
Page last reviewed: April 16, 2008
Content Source: Division of Parasitic Diseases (DPD)
National Center for Zoonotic, Vector-Borne, and Enteric Diseases (ZVED)