Gastroenteritis Cryptosporidiosis

Overview

Cryptosporidiosis — often just called 'crypto' — is an infection of the gut caused by a tiny parasite called Cryptosporidium (say: krip-toe-spore-ID-ee-um). A parasite is a very small living thing that can live inside your body and make you ill. Crypto settles in the lining of your bowel (the long tube that digests food) and causes watery diarrhoea, stomach cramps and sometimes vomiting. It spreads easily through water, food, animals and contact with someone who is infected. Most healthy people get better on their own within a couple of weeks, but the diarrhoea can be unpleasant and tiring while it lasts.

Yes, it is a common cause of infectious diarrhoea worldwide, and cases in the UK and other countries tend to rise in late summer and early autumn. Many people who catch it never see a doctor because the illness settles by itself.

Anyone can catch crypto, but it is seen most often in young children (especially those in nursery or childcare), people who have travelled to areas with poor water sanitation, people who swim in pools, lakes or rivers, people in close contact with farm animals, and people whose immune system is weakened. It affects people of all ages and backgrounds.

Symptoms

Common symptoms

• Watery diarrhoea, which may be sudden and very loose
• Stomach cramps and pain
• Feeling sick (nausea) and sometimes being sick (vomiting)
• A mild fever
• Loss of appetite and feeling generally washed out
• Some weight loss while you are unwell
• Symptoms usually start about 2 to 10 days after you picked up the infection

Symptoms in children

• More frequent, very watery nappies or diarrhoea
• Fewer wet nappies than usual, or no urine for several hours
• Dry mouth, no tears when crying, or sunken eyes
• Being unusually sleepy, floppy or hard to wake
• Refusing feeds or drinks, or being sick after them
• Children can become dehydrated faster than adults, so watch them closely

Symptoms in older adults

• Feeling dizzy or light-headed when standing up
• Weakness, tiredness and confusion (confusion can be a sign of dehydration)
• Passing less urine, or urine that is dark yellow
• Existing health problems, such as heart or kidney conditions, feeling harder to manage
• A higher chance of needing medical support to replace fluids

Causes

Main causes

• Swallowing the parasite, which is passed out in the poo of infected people and animals
• Drinking or swallowing contaminated water — from swimming pools, hot tubs, lakes, rivers, streams or private water supplies
• Eating contaminated food, especially unwashed fruit and vegetables or unpasteurised milk
• Touching an infected animal, particularly calves and lambs, and then not washing your hands before eating
• Close contact with someone who is infected, such as changing nappies or sharing towels and utensils
• Sexual contact that involves the mouth and bottom (this is a recognised way crypto can spread)

Risk factors

• Working in or attending a nursery, childcare setting or school
• Caring for someone with diarrhoea, or living in the same household
• Travelling to countries where drinking water and sanitation are less safe
• Swimming in pools, splash parks, lakes or rivers, or swallowing water while swimming
• Visiting a farm or petting zoo, or handling young farm animals
• A weakened immune system, for example from certain medical conditions or treatments that suppress immunity
• Drinking untreated water from a private well or stream

When to see a doctor

See a doctor urgently if:

• You or your child has signs of dehydration that are not getting better
• There is blood in the diarrhoea
• The diarrhoea has lasted more than 7 days
• You have a weakened immune system and develop diarrhoea
• Your baby is under 6 months old and has diarrhoea
• You have severe tummy pain or a very high temperature

Book a routine appointment if:

• You want advice about fluids, feeding or returning to work, school or nursery
• The diarrhoea keeps coming back after you felt better
• You have recently travelled abroad or been swimming and want to know whether testing is needed
• You are unsure whether you or your child needs to be checked

Diagnosis

A doctor can often suspect crypto from your symptoms, but because many tummy bugs look similar, the infection is usually confirmed with a stool sample. You will be given a small pot and asked to put in a sample of your poo, which is then sent to a laboratory to look for the parasite. In the UK, crypto is one of the infections laboratories routinely check for when they test a stool sample.

Tests that may be done

• A stool (poo) sample sent to the laboratory — this is the main test
• Sometimes a second sample, because the parasite is not always found in every sample
• Laboratory tests that look for the parasite's genetic material (called PCR), which are very accurate
• A blood test or urine test may be done if you seem dehydrated, to check your salt levels and kidney function
• If symptoms are unusual or long-lasting, your doctor may arrange further tests to rule out other causes

What to expect at your appointment

You will usually be asked to drop the sample pot off at your GP surgery or a local health centre. Results normally come back within a few days, though this varies by area. While you wait, keep drinking fluids and keep washing your hands carefully to avoid passing the infection to others. Your GP or the local health protection team may contact you to ask where you think you picked up the infection — this helps them spot outbreaks linked to swimming pools or water supplies.

Treatment

For most healthy people, treatment is about supporting your body while it clears the infection. There is no routine medicine that cures crypto in everyone, and in healthy adults and children the illness usually settles by itself. The most important treatment is replacing the fluid and salts you lose through diarrhoea and vomiting.

Self-care at home

• Drink small sips of fluid often — water is fine, and oral rehydration salts (sachets from a pharmacy that replace salts and sugars) are helpful if you have been losing a lot of fluid
• Keep feeding babies and children — continue breast milk or formula, and offer extra drinks
• Rest as much as you need to
• Eat small, light meals when you feel able — there is no need to avoid food altogether
• Avoid alcohol and drinks with a lot of sugar, which can make diarrhoea worse
• Wash your hands thoroughly with soap and water after every visit to the toilet and before preparing food
• Stay off work, school or nursery until you have been free of diarrhoea for at least 48 hours
• Do not swim in pools, lakes or the sea until at least 2 weeks after your symptoms have completely stopped — this is the advice given by UK health guidance

Medical treatments

If you are very dehydrated, you may need fluids given through a drip in hospital. For people with a weakened immune system, doctors may consider specific medicines that target the parasite, and they will discuss the risks and benefits with you. Anti-diarrhoea medicines are not usually recommended for this infection because they can make it harder for your body to clear the parasite — always ask a pharmacist or doctor before taking anything for diarrhoea, and never give them to a young child without medical advice.

When is surgery considered?

Surgery is not needed for cryptosporidiosis. Very rarely, the infection can affect the gallbladder and cause problems that need specialist review, but this is uncommon.

Living with this condition

While you are unwell, life will revolve around the toilet, drinks and rest. Plan to be at home for a few days and keep a water bottle nearby so you can sip regularly. Keep a close eye on young children and older relatives for signs of dehydration. Wash your hands often, use your own towel, and clean the toilet and bathroom surfaces regularly. You can return to normal activities once you have had no diarrhoea for 48 hours.

Lifestyle tips

• Build handwashing into your routine — after the toilet, after nappy changes, before eating and before preparing food
• Keep a separate towel and flannel for the person who is unwell
• Clean toilet seats, handles, taps and bathroom surfaces with normal household cleaner
• Avoid preparing food for other people until 48 hours after your symptoms stop
• Do not share drinks bottles, cutlery or toothbrushes
• Wait at least 2 weeks after symptoms stop before swimming again

Diet and exercise

There is no special diet that cures crypto. Eat light, ordinary foods when you feel hungry, and don't force yourself if you don't. Fluids matter far more than food in the first few days. Once you are feeling better, gradually return to your normal diet. Take it easy with exercise — wait until you have eaten normally for a day or two and feel steady on your feet, then start gently with walking and build up. Tiredness can linger for a week or so after the diarrhoea stops, which is normal.

Mental health and emotional wellbeing

Being stuck at home with diarrhoea can feel isolating, boring and worrying, especially if you are missing work or looking after a poorly child. It is common to feel anxious about passing the infection on, or frustrated that you cannot do your usual activities. Remind yourself that this is usually a short-term illness that settles. If you feel low, anxious or overwhelmed, talk to someone you trust or to your GP — support is available. If you ever have thoughts of harming yourself, contact your local emergency number or a crisis line in your country straight away.

Prevention

You can greatly lower your risk with good hand hygiene and care about what you swallow. Wash your hands with soap and water after using the toilet, changing nappies, handling animals or visiting a farm, and always before preparing or eating food. Alcohol hand gels do not work well against crypto — soap and water is much better. When travelling, drink bottled or boiled water if you are unsure about the supply, and avoid ice made from tap water. Do not swallow water while swimming, and never swim if you have had diarrhoea in the past 2 weeks.

Vaccines

There is currently no vaccine to prevent cryptosporidiosis.

Screening programmes

There is no routine screening programme for crypto. Testing is only done when someone has symptoms that suggest it.

Complications

If left untreated

• Dehydration, which can become serious quickly in babies, young children and older adults
• Weight loss and feeling very weak or tired
• Diarrhoea that drags on for several weeks, especially in people with a weakened immune system
• Trouble absorbing nutrients from food if the illness is prolonged
• Rarely, the infection can affect other parts of the body, such as the gallbladder or the lungs, particularly in people with a weakened immune system

Long-term outlook

The outlook is good for most people. Healthy adults and children usually recover fully within 1 to 2 weeks, though tiredness and loose stools can take a little longer to settle. People with a weakened immune system may have a longer or more difficult illness, and their doctor will want to keep a closer eye on them — but support and treatment are available. The great majority of people make a full recovery and get back to normal life.

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