Avian Flu Diary: Tales From The Crypto

# 6359

Earlier today (June 1st), the UK’s Health Protection Agency issued a statement on their investigation into an unusually large number of gastrointestinal illnesses being reported across England due to the Cryptosporidium parasite, or as it is commonly called, “Crypto”.

Since this little nasty is one of the most common causes of waterborne diseases among humans (even in developed countries), and it is often acquired during the summer swimming season, today seemed like a good day to take a look at this hardy little parasite.

First, the HPA announcement, which has as yet been unable to locate a common source for the outbreaks reported across England over the past 3 weeks.

Increase in cases of cryptosporidiosis

1 June 2012

The Health Protection Agency (HPA) can confirm it is investigating a recent increase in cases of the gastrointestinal infection, cryptosporidiosis, across four regions in England – the North East, Yorkshire, West Midlands and East Midlands.

To date, 267 cases of cryptosporidiosis have been confirmed in the affected areas since 11 May 2012, compared to 73 cases across the four regions for the whole of May 2011.

The HPA is leading a multi-agency investigation to determine whether these recent cases are linked. So far investigations have not identified a possible source of infection and the distribution of cases suggests it is unlikely that public water supplies are implicated.

Cryptosporidiosis is caused by a tiny organism called Cryptosporidium, which is found in soil, food, water, or surfaces that have been contaminated with infected human or animal droppings. People can become infected by consuming contaminated water or food, by swimming in contaminated water, for example in lakes or rivers, or through contact with infected animals. The most common symptom is diarrhoea, which can range from mild to severe.

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Photo Credit CDC PHIL

Although rarely fatal in healthy individuals, `Crypto’ can be deadly for the very young, the very old, and those with compromised immune systems.

Occasionally campers, swimmers, or those drawing water from untreated wells will contract Crypto here in the United States. 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.

Cryptosporidium is chlorine resistant, making it particularly difficult to eliminate from water sources. 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.

Measures that are pretty much unavailable for most of the developing world.

According to an EID Journal study published in early 2011, there are estimated to be nearly 750,000 Crypto infections in the United States each year (see Foodborne Illness Acquired in the United States—Major Pathogens), although fewer than 8,000 are usually laboratory confirmed.

For most healthy individuals, a Crypto infection is an unpleasant, but not life threatening illness. The most common symptoms (which generally last 1 to 2 weeks) are:

Watery Diarrhea
Stomach cramps or pain
Dehydration
Nausea
Vomiting
Fever
Weight loss

And some people (the lucky ones) will have no symptoms at all. Most people with healthy immune systems will recover without any specific treatment, beyond drinking lots of fluids to prevent dehydration.

As far as how it is spread, the CDC lists:

Crypto lives in the intestine of infected humans or animals. An infected person or animal sheds Cryptosporidium parasites in the stool. Millions of Crypto parasites can be released in a bowel movement from an infected human or animal. Shedding begins when the symptoms begin and can last for weeks after the symptoms (e.g., diarrhea) stop. You can become infected after accidentally swallowing the parasite. Crypto may be found in soil, food, water, or surfaces that have been contaminated with the feces from infected humans or animals. Crypto is not spread by contact with blood. Crypto can be spread:

By putting something in your mouth or accidentally swallowing something that has come in contact with the stool of a person or animal infected with Crypto.

By swallowing recreational water contaminated with Crypto. Recreational water can be contaminated with sewage or feces from humans or animals.

By swallowing water or beverages contaminated by stool from infected humans or animals.

By eating uncooked food contaminated with Crypto. All fruits and vegetables you plan to eat raw should be thoroughly washed with uncontaminated water.

By touching your mouth with contaminated hands. Hands can become contaminated through a variety of activities, such as:

touching surfaces (e.g., toys, bathroom fixtures, changing tables, diaper pails) that have been contaminated by stool from an infected person,

changing diapers,

caring for an infected person, and

handling an infected cow or calf.

Given its prevalence in the environment, and the number of human infections each year, prevention is key.

Again from the CDC.

Prevention & Control of Cryptosporidiosis

The following recommendations are intended to help prevent and control cryptosporidiosis.

Practice Good Hygiene

Everywhere

Wash hands with soap and water for at least 20 seconds, rubbing hands together vigorously and scrubbing all surfaces:

Before preparing or eating food

After using the toilet

After changing diapers or cleaning up a child who has used the toilet

Before and after tending to someone who is ill with diarrhea

After handling an animal or animal waste

At child care facilities

To reduce the risk of disease transmission, children with diarrhea should be excluded from child care settings until the diarrhea has stopped.

At recreational water venues (pools, interactive fountains, lakes, ocean)

Protect others by not swimming if you are experiencing diarrhea (this is essential for children in diapers). If diagnosed with cryptosporidiosis, do not swim for at least 2 weeks after diarrhea stops.

Shower before entering the water.

Wash children thoroughly (especially their bottoms) with soap and water after they use the toilet or their diapers are changed and before they enter the water.

Take children on frequent bathroom breaks and check their diapers often.

Change diapers in the bathroom, not at the poolside.

Around animals

Minimize contact with the feces of all animals, particularly young animals.

When cleaning up animal feces, wear disposable gloves, and always wash hands when finished.

Wash hands after any contact with animals or their living areas.

Outside

Wash hands after gardening, even if wearing gloves.

Immunocompromised persons

Avoid close contact with any person or animal that has cryptosporidiosis. Cryptosporidiosis can become a life threatening disease for immunocompromised persons.

Do not handle animal feces because infection can be life threatening for immunocompromised persons.