May 13, 2008

CDC Partners with NSPF to Create <i>Cryptosporidium</i> Outbreak Alert System

System will send e-mail alerts after outbreaks

The Centers for Disease Control and Prevention (CDC) and the National Swimming Pool Foundation (NSPF) have established a Cryptosporidium outbreak alert system to help aquatic facilities protect their patrons from recreational water illness.

During the past two decades, Cryptosporidium has become recognized as one of the most common causes of waterborne disease (recreational water and drinking water) in the U.S. The CDC and NSPF encourage other organizations to disseminate the outbreak alert to their contacts, too.

The system is relatively simple. It focuses on building awareness of the risk and revealing prevention strategies. When CDC and NSPF learn of an outbreak, NSPF will broadcast a regional e-mail. NSPF will also send alerts to national and regional organizations who request they be notified of any outbreak. Toolkits are posted both at the CDC and NSPF websites.

Based on Cryptosporidium’s resistance to chlorine, it is not surprising that the number and severity of documented outbreaks have been increasing for over a decade. It is widely acknowledged that many outbreaks are not identified, reported or investigated. Beginning this year, state health departments will use a more convenient electronic reporting system to notify the CDC of outbreaks under investigation. When other reporting systems, like food, have been converted from paper to electronic systems, the number of documented outbreaks has increased. Thus, 2008 is likely to see an increase in documented outbreaks unless effective prevention strategies are implemented.

According to the CDC, in 2007, there were at least 18 documented Cryptosporidiosis outbreaks related to treated aquatics venues, the largest one in Utah affecting more than 1,900 people. Other large outbreaks, including the New York outbreak in 2005, demonstrate that Cryptosporidium outbreaks will quickly spread to impact many states, facilities and thousands of people. “There is little doubt that Cryptosporidium outbreaks will happen again this season, and they will likely spread if we don't work together to contain them early,” said Dr. Michael J. Beach, associate director for healthy water with the National Center for Zoonotic, Vector-Borne and Enteric Diseases (NCZVED) at the CDC.

The NSPF encourages facility operators and service companies to start a dialogue with their public health officials about the Cryptosporidium risk in their area. When public health officials and facility operators and managers partner to educate the public, a larger audience can be reached. NSPF is excited to help convey these important prevention messages.

Facilities should consider other measures to reduce outbreak risks at their facility. Studies have shown using supplemental disinfection, such as in-line ultraviolet radiation and ozone, can reduce the transmission of Cryptosporidium. Keep in mind that due to dilution, not all water passes through the system. Additional strategies to reduce risk include periodic hyperchlorination and improving water circulation throughout the pool, increasing turnover rates and using flocculants or water clarifiers. Chlorine dioxide is also effective at inactivating Cryptosporidium. It can be used in some countries, but is not registered for this particular use in the U.S. at this time.

To sign up to receive outbreak alert notifications or read more information on the alert system and the toolkit contents, visit