MMWR: More Tales From The Crypto

Photo Credit CDC PHIL



#14,151

Several times over past few years we've looked at water and food borne illness outbreaks due to parasites - both in the United States and around the world - involving cyclospora & cryptosporidium. 

CDC HAN: Increased Cyclospora Infection, United States, Summer 2017

MMWR: Cyclosporiasis Outbreak Summer 2013

Eurosurveillance: More Tales From The Crypto

UK: Return To The Crypto

While Cyclosporiasis has been making inroads and headlines the past few years, Cryptosporidiosis still leads the pack, with an EID study published in early 2011 estimating 750,000 Crypto infections in the U.S. each year (see Foodborne Illness Acquired in the United States—Major Pathogens), although only about 8,000 are laboratory confirmed. 

Cryptosporidium is an extremely chlorine-tolerant parasite, making it particularly difficult to eliminate from swimming pools, fountains, and public water sources.   

Occasionally campers, swimmers, or those drawing water from untreated wells will contract Crypto, but the largest outbreak occurred in Milwaukee in 1993, when Cryptosporidium entered the public water supply (exactly how, remains a mystery), and sickened 400,000 people and killed more than 100 who were immunocompromised.

The Milwaukee incident has led to increased water testing, and the use of ozone, filters, and other interventions across the nation to help make our water supply safer.

Despite these improvements, the CDC reports a steady increase in Crypto cases over the past decade.  Yesterday's MMWR carried a report on 444 outbreaks reported over the past decade.

First the CDC's press release, and then a link to the full MMWR report.

CDC Press Release: Outbreaks of diarrhea caused by summertime parasite increased from 2009 through 2017

Pools, cattle, and childcare settings continue to be important sources of Crypto outbreaks

Press Release

Embargoed Until: Thursday, June 27, 2019, 1:00 p.m. ET
Contact: Media Relations (404) 639-3286

Outbreaks of Cryptosporidium (Crypto) in the United States increased an average 13% each year from 2009-2017, according to a report published in CDC’s Morbidity and Mortality Weekly Report.

Crypto, a parasite, is spread through the poop of infected humans or animals. People can get sick after they swallow the parasite in contaminated water or food or after contact with infected people or animals. Crypto is the leading cause of disease outbreaks in the United States linked to water, specifically outbreaks linked to pools or water playgrounds.

Hundreds of outbreaks caused by Crypto

The report describes 444 outbreaks reported from 2009 through 2017, resulting in 7,465 people becoming sick, 287 hospitalizations, and one death.

• 35% of the outbreaks were linked to treated swimming water in places like pools and water playgrounds.
• 15% were linked to contact with cattle, particularly calves who were still nursing.
• 13% were linked to contact with infected people in childcare settings.
• 3% were linked to drinking raw (unpasteurized) milk or apple cider.

Improvements in testing patients for Crypto in recent years might be contributing to increased detection of outbreaks.

Michele Hlavsa, R.N., M.P.H., chief of CDC’s Healthy Swimming Program

“Young children can get seriously sick and easily spread Crypto. They don’t know how to use the toilet and wash their hands, or are just learning how. But we as parents can take steps to help keep our kids healthy in the water, around animals, and in childcare.”

Crypto is a challenging parasite

Crypto is protected by an outer shell that makes it tough to kill. For example, it can survive for days in chlorinated water in pools and water playgrounds or on surfaces disinfected with chlorine bleach. Crypto can easily cause outbreaks because it only takes a few germs to make someone sick, and there can be millions of Crypto germs in poop. Someone sick with Crypto can have diarrhea for up to three weeks.

Protect yourself and family from getting sick

Outbreaks caused by Crypto occur most commonly in the summer. Follow these effective steps to protect yourself and others this summer and year-round:

• Do not swim or let kids swim if they have diarrhea.
• If diagnosed with cryptosporidiosis, do not swim until two weeks after diarrhea completely stops.
• Do not swallow the water you swim in.
• Keep kids sick with diarrhea at home and away from childcare.
• Wash your hands with soap and water after coming in contact with animals or anything in their environment, especially animal poop. Alcohol-based hand sanitizers do not work effectively on Crypto.
• Remove shoes worn in the animal environments (for example, in barns) before going inside your home.
• If you drink milk or apple cider, only buy if it has been pasteurized.

National surveillance system can help detect outbreaks

CryptoNet is the first U.S. national tracking system for a parasitic disease that is based on DNA fingerprinting. Crypto DNA fingerprinting can help determine how the parasite spreads and help detect and investigate outbreaks.

For more information on Crypto, visit https://www.cdc.gov/parasites/crypto/gen_info/prevention-general-public.html.

Excerpts from yesterday's MMWR report are below. Follow the link to read it in its entirety.

Cryptosporidiosis Outbreaks — United States, 2009–2017

Weekly / June 28, 2019 / 68(25);568–572

Radhika Gharpure, DVM1,2; Ariana Perez, MPH1,3; Allison D. Miller, MPH1,4; Mary E. Wikswo, MPH5; Rachel Silver, MPH1,3; Michele C. Hlavsa, MPH1

Summary

What is already known about this topic?

Cryptosporidium is the leading cause of outbreaks of diarrhea linked to water and the third leading cause of diarrhea associated with animal contact in the United States.

What is added by this report?

During 2009–2017, 444 cryptosporidiosis outbreaks, resulting in 7,465 cases were reported by 40 states and Puerto Rico. The number of reported outbreaks has increased an average of approximately 13% per year. Leading causes include swallowing contaminated water in pools or water playgrounds, contact with infected cattle, and contact with infected persons in child care settings.

What are the implications for public health practice?

To prevent cryptosporidiosis outbreaks, CDC recommends not swimming or attending child care if ill with diarrhea and recommends hand washing after contact with animals.

Cryptosporidium is a parasite that causes cryptosporidiosis, a profuse, watery diarrhea that can last up to 3 weeks in immunocompetent patients and can lead to life-threatening malnutrition and wasting in immunocompromised patients.* 

Fecal-oral transmission can occur by ingestion of contaminated recreational water, drinking water, or food, or through contact with infected persons or animals. 

For the period 2009–2017, public health officials from 40 states and Puerto Rico voluntarily reported 444 cryptosporidiosis outbreaks resulting in 7,465 cases. Exposure to treated recreational water (e.g., in pools and water playgrounds) was associated with 156 (35.1%) outbreaks resulting in 4,232 (56.7%) cases.

Other predominant outbreak exposures included contact with cattle (65 outbreaks; 14.6%) and contact with infected persons in child care settings (57; 12.8%). The annual number of reported cryptosporidiosis outbreaks overall increased an average of approximately 13% per year over time. 

Reversing this trend will require dissemination of prevention messages to discourage swimming or attending child care while ill with diarrhea and encourage hand washing after contact with animals. Prevention and control measures can be optimized by improving understanding of Cryptosporidium transmission through regular analysis of systematically collected epidemiologic and molecular characterization data.

(Continue . . . )

To learn more about Crypto, the CDC maintains a large Crypto Information Site.