What is dysentery

Dysentery is an infection of the intestines that causes diarrhea containing blood or mucus.

Other symptoms of dysentery can include:

• painful stomach cramps
• nausea or vomiting
• a fever of 100.4 °F (38 °C) or above

Dysentery is highly infectious and can be passed on if you don’t take the right precautions, such as properly and regularly washing your hands.

Types of dysentery

There are two main types of dysentery:

1. Bacillary dysentery or shigellosis – caused by shigella bacteria; this is the most common type of dysentery in the UK
2. Amoebic dysentery or amoebiasis – caused by an amoeba (single-celled parasite) called Entamoeba histolytica, which is mainly found in tropical areas; this type of dysentery is usually picked up abroad

Is dysentery contagious?

Yes. Bacillary and amoebic dysentery are both highly contagious and can be passed on if the feces (poop) of an infected person gets into another person’s mouth. You should stay at home until at least 48 hours after the last episode of diarrhea to reduce the risk of passing the infection on to others.

How you can avoid passing on dysentery

Handwashing is the most important way to stop the spread of infection. You’re infectious to other people while you’re ill and have symptoms.

Take the following steps to avoid passing the illness on to others:

• Wash your hands thoroughly with soap and water after going to the toilet. Read more about how to wash your hands.
• Stay away from work or school until you’ve been completely free from any symptoms for at least 48 hours.
• Help young children to wash their hands properly.
• Don’t prepare food for others until you’ve been symptom free for at least 48 hours.
• Don’t go swimming until you’ve been symptom free for at least 48 hours.
• Where possible, stay away from other people until your symptoms have stopped.
• Wash all dirty clothes, bedding and towels on the hottest possible cycle of the washing machine.
• Clean toilet seats and toilet bowls, and flush handles, taps and sinks with detergent and hot water after use, followed by a household disinfectant.
• Avoid sexual contact until you’ve been symptom free for at least 48 hours.

As shigella is easily passed on to others, you may need to submit stool (poo) samples to be given the all clear to return to work, school, nursery or a childminder.

The type of shigella you have and whether or not you or others are in a risk group will influence how long you need to stay away.

Risk groups are people in certain occupations – including healthcare workers and people who handle food – as well as people who need help with personal hygiene and very young children. Your environmental health officer will be able to advise you about this.

How do you get dysentery?

Bacillary and amoebic dysentery are both highly infectious and can be passed on if the feces (poop) of an infected person gets into another person’s mouth.

This can happen if someone with the infection doesn’t wash their hands after going to the toilet and then touches food, surfaces or another person.

This can happen when you:

• Touch your mouth. If you don’t wash your hands well after changing the diaper of a child who has shigella or entamoeba infection, you may become infected yourself.
• Direct person-to-person contact is the most common way the disease is spread.
• Eat contaminated food. Infected people who handle food can transmit the bacteria to people who eat the food. Food can also become contaminated if it grows in a field that contains sewage.
• Swallow contaminated water. Water may become contaminated either from sewage or from a person with shigella infection swimming in it.

In the US, the infection usually affects groups of people in close contact, such as in families, schools and nurseries.

There’s also a chance of picking up the infection through anal or anal-oral sex (“rimming”).

In developing countries with poor sanitation, infected feces may contaminate the water supply or food, particularly cold uncooked food.

What causes dysentery

Bacillary and amoebic dysentery are both highly infectious and can be passed on if the feces (poop) of an infected person gets into another person’s mouth.

This can happen if someone with the infection doesn’t wash their hands after going to the toilet and then touches food, surfaces or another person.

In the US, the infection usually affects groups of people in close contact, such as in families, schools and nurseries.

There’s also a chance of picking up the infection through anal or anal-oral sex (“rimming”).

In developing countries with poor sanitation, infected feces may contaminate the water supply or food, particularly cold uncooked food.

Amoebic dysentery

Amoebic dysentery or amoebiasis is a common parasitic intestinal infection that is transmitted via fecal-oral route, either directly by person-to-person contact (such as by diaper-changing or sexual practices) or indirectly by eating or drinking fecally contaminated food or water ¹⁾. Amoebic dysentery is caused by any of the amoebas of the Entamoeba group ²⁾. Amoebic dysentery may present with no symptoms or mild to severe symptoms including abdominal pain, diarrhea, or bloody diarrhea. Most patients have a gradual illness onset days or weeks after infection. Symptoms include cramps, watery or bloody diarrhea, and weight loss and may last several weeks ³⁾. Severe complications may include inflammation and perforation resulting in peritonitis. People affected may develop anemia ⁴⁾.

If the parasite reaches the bloodstream, it can spread through the body to other organs (extraintestinal amebiasis) and most commonly end up in the liver causing amoebic liver abscesses. Liver abscesses can occur without previous diarrhea ⁵⁾. Amebic liver abscesses may be asymptomatic, but most patients present with fever and right upper quadrant abdominal pain, usually in the absence of diarrhea ⁶⁾.

Amoebiasis is present all over the world. Each year, about 40,000 to 110,000 people die from amoebiasis infection ⁷⁾.

Amoebic dysentery diagnosis

Diagnosis is typically by stool examination using a microscope. An increased white blood cell count may be present. The most accurate test is specific antibodies in the blood.

Microscopy does not distinguish between Entamoeba histolytica (known to be pathogenic), Entamoeba bangladeshi, Entamoeba dispar, and Entamoeba moshkovskii. Entamoeba dispar and Entamoeba moshkovskii have historically been considered non-pathogenic, but evidence is mounting that Entamoeba moshkovskii can cause illness; Entamoeba bangladeshi has only recently been identified, so its pathogenic potential is not well understood. More specific tests such as EIA (enzyme-linked immunosorbent assay or ELISA) or PCR (polymerase chain reaction) are needed to confirm the diagnosis of Entamoeba histolytica. Additionally, serologic tests can help diagnose extraintestinal amebiasis.

Amoebic dysentery treatment

Two treatment options are possible, depending on the location.

Amoebiasis in tissue is treated with metronidazole, tinidazole, nitazoxanide, dehydroemetine or chloroquine.

For symptomatic intestinal infection and extraintestinal disease, treatment with metronidazole or tinidazole should be followed by treatment with iodoquinol or paromomycin ⁸⁾. An intestinal infection is treated with diloxanide furoate or iodoquinoline. Effective treatment may require a combination of medications.

Asymptomatic patients infected with Entamoeba histolytica should also be treated with iodoquinol or paromomycin, because they can infect others and because 4%– 10% develop disease within a year if left untreated ⁹⁾.

Bacillary dysentery

Bacillary dysentery or shigellosis is an infectious disease caused by a group of bacteria called Shigella ¹⁰⁾. Shigella causes about 500,000 cases of diarrhea in the United States annually ¹¹⁾. Most who are infected with Shigella develop diarrhea, fever, and stomach cramps starting a day or two after they are exposed to the bacteria. Shigellosis usually resolves in 5 to 7 days. Some people who are infected may have no symptoms at all, but may still pass the Shigella bacteria to others. The spread of Shigella can be stopped by frequent and careful handwashing with soap and taking other hygiene measures.

There are four different species of Shigella:

1. Shigella sonnei (the most common species in the United States)
2. Shigella flexneri
3. Shigella boydii
4. Shigella dysenteriae

Shigella dysenteriae and Shigella boydii are rare in the United States, though they continue to be important causes of disease in the developing world. Shigella dysenteriae type 1 can be deadly ¹²⁾.

How is bacillary dysentery spread?

Shigella germs are in the stool (poop) of sick people while they have diarrhea and for up to a week or two after the diarrhea has gone away. Shigella germs are very contagious; it takes just a small number of Shigella germs to make someone sick. People can get shigellosis when they put something in their mouths or swallow something that has come into contact with the stool of someone else who is sick with shigellosis. People could get sick by:

• Getting Shigella germs on their hands and then touching your food or mouth. You can get Shigella germs on your hands after:
  • Touching surfaces contaminated with germs from stool from a sick person, such as toys, bathroom fixtures, changing tables or diaper pails
  • Changing the diaper of a sick child or caring for a sick person
• Eating food that was prepared by someone who is sick with shigellosis
• Swallowing recreational water (for example, lake or river water) while swimming or drinking water that is contaminated with stool (poop) containing the germ
• Having exposure to stool during sexual contact with someone who is sick or recently (several weeks) recovered from shigellosis.

Who is most likely to get bacillary dysentery?

• Young children are the most likely to get bacillary dysentery, but people of all ages are affected 1. Many outbreaks are related to childcare settings and schools, and illness commonly spreads from young children to their family members and others in their communities because it is so contagious.
• Travelers to developing countries may be more likely to get shigellosis, and to become infected with strains of Shigella bacteria that are resistant to important antibiotics ¹³⁾. Travelers may be exposed through contaminated food, water (both drinking and recreational water), or surfaces. Travelers can protect themselves by strictly following food and water precautions, and washing hands with soap frequently.
• Gay and bisexual men and other men who have sex with men are more likely to acquire shigellosis than the general adult population ¹⁴⁾. Shigella passes from feces or soiled fingers of one person to the mouth of another person, which can happen during sexual activity. Many shigellosis outbreaks among men who have sex with men have been reported in the United States, Canada, Japan, and Europe since 1999 ¹⁵⁾.
• People who have weakened immune systems due to illness (such as HIV) or medical treatment (such as chemotherapy for cancer) can get a more serious illness. A severe shigellosis may involve the infection spreading into the blood, which can be life-threatening ¹⁶⁾.
• Large outbreaks of shigellosis often start in childcare settings and spread among small social groups such as in traditionally observant Jewish communities ¹⁷⁾. Similar outbreaks could occur among any race, ethnicity or community social circle because Shigella germs can spread easily from one person to another.

How can I reduce my chance of getting bacillary dysentery?

You can reduce your chance of getting sick from Shigella by taking these steps:

• Carefully washing your hands with soap and water during key times:
  • Before preparing food and eating.
  • After changing a diaper or helping to clean another person who has defecated (pooped).
• If you care for a child in diapers who has shigellosis, promptly throw away the soiled diapers in a covered, lined garbage can. Wash your hands and the child’s hands carefully with soap and water right after changing the diapers. Clean up any leaks or spills of diaper contents immediately.
• Avoid swallowing water from ponds, lakes, or untreated swimming pools.
• When traveling internationally, stick to safe eating and drinking habits, and wash hands often with soap and water.
• Avoid having sex (vaginal, anal, and oral) for one week after your partner recovers from diarrhea. Because Shigella germs may be in stool for several weeks, follow safe sexual practices, or ideally avoid having sex, for several weeks after your partner has recovered.

I was diagnosed with bacillary dysentery. What can I do to avoid giving it to other people?

• Wash your hands carefully and frequently with soap and water, especially after using the bathroom.
• Do not prepare food for others while you are sick. After you get better, wash your hands carefully with soap and water before preparing food for others.
• Stay home from childcare, school and food service facilities while sick. Your local health department may have a policy on when to return to childcare or school. Refer to your local health department website for more information.
• Avoid swimming until you have fully recovered.
• Wait to have sex (vaginal, anal, and oral) for one week after you no longer have diarrhea. Because Shigella germs may be in stool for several weeks, follow safe sexual practices, or ideally avoid having sex, for several weeks after you have recovered.

My child was diagnosed with bacillary dysentery. How can I keep others from catching it?

• Supervise handwashing of toddlers and small children after they use the bathroom. Wash your hands and your infant’s hands with soap and water after diaper changes.
• Throw away soiled diapers in a covered, lined garbage can. Clean diaper changing areas after using them.
• Keep your child out of childcare and group play settings while sick with diarrhea, and follow the guidance of your local health department about returning your child to their childcare facility.
• Avoid taking your child swimming or to group water play venues until after they no longer have diarrhea.
• Have children and staff shower with soap before swimming.
• If a child is too young to shower independently, have staff wash the child, particularly the rear end, with soap and water.
• Take frequent bathroom breaks or check their diapers often.
• Change diapers in a diaper-changing area or bathroom and not by the water.
• Discourage children from getting the water in their mouths and swallowing it.

What are the symptoms of bacillary dysentery and how long do they last?

Symptoms of shigellosis typically start 1–2 days after exposure to the germ and include:

• Diarrhea (sometimes bloody)
• Fever
• Stomach pain
• Feeling the need to pass stool [poop] even when the bowels are empty

For most people, symptoms usually last about 5 to 7 days. In some cases, it may take several months before bowel habits (for example, how often someone passes stool and the consistency of their stool) are entirely normal.

Bacillary dysentery diagnosis

Diarrhea and bloody diarrhea can result from a number of diseases. Confirming shigellosis involves taking a sample of your stool to be tested in a laboratory for the presence of shigella bacteria or their toxins.

How can bacillary dysentery be treated?

People who have shigellosis usually get better without antibiotic treatment in 5 to 7 days. People with mild shigellosis may need only fluids and rest. Bismuth subsalicylate (for example, Pepto-Bismol) may be helpful ¹⁸⁾, but people sick with shigellosis should not use medications that cause the gut to slow down and interfere with the way the body digests food, such as loperamide (for example, Imodium) or diphenoxylate with atropine (for example, Lomotil) ¹⁹⁾.

Healthcare providers may prescribe antibiotics for people with severe cases of shigellosis to help them get better faster. However, some antibiotics are not effective against certain types of Shigella. Healthcare providers can order laboratory tests to determine which antibiotics are likely to work. Tell your healthcare provider if you do not get better within a couple of days after starting antibiotics. They can do more tests to learn whether your type of Shigella bacteria can be treated effectively with the antibiotic you are taking. If not, your doctor may prescribe another type of antibiotic.

Fluid and salt replacement

For generally healthy adults, drinking water may be enough to counteract the dehydrating effects of diarrhea.

Children may benefit from an oral rehydration solution, such as Pedialyte, available in drugstores. Many pharmacies carry their own brands.

Children and adults who are severely dehydrated need treatment in a hospital emergency room, where they can receive salts and fluids through a vein (intravenously), rather than by mouth. Intravenous hydration provides the body with water and essential nutrients much more quickly than oral solutions do.

Reducing your risk of catching dysentery

You can reduce your risk of getting dysentery by:

• washing your hands with soap and warm water after using the toilet and regularly throughout the day
• washing your hands before handling, eating or cooking food
• avoiding sharing towels
• washing the laundry of an infected person on the hottest setting possible

Food safety and home hygiene

How to store food and leftovers

What goes in the fridge?

Some foods need to be kept in the fridge to help slow down germs’ growth and keep food fresh and safe for longer.

These are foods marked with a “use by” date and “keep refrigerated” on the label, such as milk, meat and ready meals.

Cool down leftovers as quickly as possible (within two hours), store them in the fridge and eat them within two days.

Avoid putting open tin cans in the fridge, as the food inside may develop a metallic taste.

Follow the manufacturer’s instructions or place the contents in a storage container or covered bowl before refrigerating.

Fridge maintenance

Keep your fridge temperature at 39.2 °F (4 ° C) or below. If your fridge has a digital temperature display you may wish to check it against an internal fridge thermometer now and again to make sure it’s accurate.

Clean and inspect your fridge regularly to ensure it remains hygienic and in good working order.

“Use by” dates

No food lasts forever, how ever well it is stored. Most pre-packed foods carry either a “use by” or a “best before” date.

• “Use by” dates appear on foods that go off quite quickly. It can be dangerous to eat foods past this date.
• “Best before” dates are for foods with a longer life. They show how long the food will be at its best.

Food can look and smell fine even after its “use by” date but that doesn’t mean it’s safe to eat. It could still contain bugs that could make you ill.

Eating food past its “best before” date is not dangerous, but the food may not be good quality.

Freezing food

You can freeze pretty much everything, including:

• yogurt
• cheese (except soft cheese as the freezing process affects the texture)
• milk
• meat
• fish
• eggs, including boiled eggs
• bananas: peel and wrap them or place in an airtight container before freezing
• baked goods
• rice: read our safety tips
• bread

Anything with a high water content like strawberries and tomatoes will go squishy but are still fine to cook with.

Place food in an airtight container or wrap it tightly in freezer bags or similar before placing in the freezer otherwise the cold air will dry it out.

Storing eggs

Eggs are best stored in the fridge as they are kept at a constant temperature.

Eggs can also be frozen. Two ways to freeze eggs:

• crack the egg and separate yolks and whites into separate plastic containers or food bags before freezing. This is handy for baking.
• crack the egg into a plastic tub and beat it before freezing – great for omelettes and scrambled eggs.

You can safely store a boiled egg in the fridge for a couple of days. Boiled eggs can also be frozen.

Storing meat and poultry

It’s important to store meat safely in the fridge to stop bacteria from spreading and avoid food poisoning.

• Store raw meat and poultry in clean, sealed containers on the bottom shelf of the fridge.
• Follow any storage instructions on the label and don’t eat meat after its use by date.
• Keep cooked meat separate from raw meat and ready-to-eat foods in general.

Freezing and defrosting meat and fish

It’s safe to freeze meat and fish as long as you:

• freeze it any time before its use by date
• defrost meat and fish thoroughly before cooking – lots of liquid will come out as meat thaws, so stand it in a bowl to stop bacteria in the juice spreading to other things
• defrost meat or fish in a microwave if you intend to cook straight away, or if not, defrost in the fridge overnight so it doesn’t get too warm
• cook food until it’s steaming hot throughout

Make sure meat is properly wrapped in the freezer or it might get freezer burn, which can make it tough and inedible.

Date and label meat in the freezer and eat it within 24 hours of defrosting.

You can freeze meat for a long time and it will still be safe to eat, but the quality will deteriorate so it’s best to eat it within three to six months.

Don’t worry if it’s frozen for longer – try marinating it before cooking to improve texture or use herbs and spices to add flavour.

Re-freezing meat and fish

Never re-freeze raw meat (including poultry) or fish that has been defrosted.

You can cook frozen meat and fish once defrosted, and then refreeze them.

You can re-freeze cooked meat and fish once, as long as they have been cooled before going into the freezer. If in doubt, don’t re-freeze.

Frozen raw foods can be defrosted once and stored in the fridge for up to 24 hours before they need to be cooked or thrown away.

To reduce wastage, divide the meal into portions before freezing and then just defrost what you need.

Using leftovers

Don’t throw away leftovers: they could be tomorrow’s lunch! Follow these tips to make the most of them:

• Cool leftovers as quickly as possible, ideally within two hours.
• Divide leftovers into individual portions and refrigerate or freeze.
• Use refrigerated leftovers within two days.
• When reheating food, make sure it is heated until it reaches a temperature of 70C for two minutes, so that it is steaming hot throughout.
• Always defrost leftovers completely, either in the fridge or in the microwave.
• When defrosted, food should be reheated only once, because the more times you cool and reheat food, the higher the risk of food poisoning.
• Cooked food that has been frozen and removed from the freezer should be reheated and eaten within 24 hours of fully defrosting.
• Foods stored in the freezer, such as ice cream and frozen desserts, should not be returned to the freezer once they have thawed.
• For safety and to reduce waste, only take out of the freezer what you intend to use within the next 24 hours.

Re-using bags

With more people re-using single-use plastic carrier bags or using a reusable bag for life, you can help prevent bacteria spreading to ready-to-eat food by:

• packing raw foods separately from ready-to-eat foods, in separate bags
• keeping one or two reusable bags just for raw foods only – don’t use the same bags for ready-to-eat foods
• checking your bags for spillages, such as raw meat juices or soil, after every use

If there has been any spillage, soiling or damage, plastic bags for life or single-use plastic carrier bags should ideally be disposed of.

Cotton and fabric-based bags for life can be put in the washing machine.

If you’re traveling overseas

If you’re traveling to a country where there’s a high risk of getting dysentery, the advice below can help prevent infection:

• Don’t drink the local water unless you’re sure it’s clean (sterile) – drink bottled water or drinks in sealed cans or bottles.
• If the water isn’t sterile, boil it for several minutes or use chemical disinfectant or a reliable filter.
• Don’t clean your teeth with tap water.
• Don’t have ice in your drinks because it may be made from unclean water.
• Avoid fresh fruit or vegetables that can’t be peeled before eating.
• Avoid food and drink sold by street vendors, except drinks in properly sealed cans or bottles.

Food and water abroad

Many illnesses are contracted through contaminated food and water.

Reduce your risk of diseases like travelers’ diarrhea by following these basic guidelines.

Drinking water

In countries with poor sanitation, don’t drink tap water or use it to brush your teeth unless it’s been treated.

Filtered, bottled, boiled or chemically treated water should be used. Bottled fizzy drinks with an intact seal are usually safe, as are boiled water and hot drinks made with boiled water. Ice in drinks should be avoided.

The most reliable way to purify water is by boiling it, but this isn’t always possible.

Chemical disinfectants, such as iodine and chlorine, will usually kill bacteria and viruses, and can easily be obtained from larger pharmacies or specialist travel shops. However, some parasites aren’t reliably killed with iodine or chlorine preparations.

Combining iodine or chlorine with filtration using a specialist filter bought from a travel shop should be effective.

Domestic water filters designed for use in the US aren’t suitable.

Foods to avoid

Foods to avoid in countries where sanitation is poor:

• salads, such as lettuce
• uncooked fruits and vegetables, unless they’ve been washed in safe water and peeled by the traveler
• fresh or cooked food that’s been allowed to stand at room temperature in warm environments or exposed to flies, such as in an open buffet
• unpasteurized milk, cheese, ice cream and other dairy products
• raw or undercooked shellfish or seafood
• food from street traders, unless it’s been recently prepared and is served hot on clean crockery

Food served in good-standard hotels or restaurants may not always be safe as it may have been contaminated during preparation.

Try to pick places to eat that have a reputation for serving safe food.

As a rule, only eat freshly prepared food that’s thoroughly cooked and served steaming hot.

Always wash your hands after going to the toilet and before preparing or eating food.

Dysentery symptoms

Signs and symptoms of dysentery usually begin a day or two after contact with either shigella or entamoeba, but may take up to a week to develop. Signs and symptoms may include:

• Diarrhea (often containing blood or mucus)
• Abdominal pain or cramps
• Fever 100.4 °F (38 °C) or above
• Nausea or vomiting

Although some people have no symptoms after they’ve been infected with shigella or entamoeba, their feces may still be contagious up to a few weeks.

Dysentery treatment

As dysentery usually clears up on its own after three to seven days, treatment isn’t usually needed. However, it’s important to drink plenty of fluids and use oral rehydration solutions (ORS) if necessary to avoid dehydration.

Over-the-counter painkillers, such as paracetamol, can help relieve pain and a fever. Avoid antidiarrheal medications, such as loperamide, because they can make things worse.

You should stay at home until at least 48 hours after the last episode of diarrhea to reduce the risk of passing the infection on to others.