General Information | Giardia | Parasites

What is giardiasis?

Giardiasis is a diarrheal disease caused by the microscopic parasite Giardia duodenalis (or “Giardia” for short). Once a person or animal has been infected with Giardia, the parasite lives in the intestines and is passed in stool (poop). Once outside the body, Giardia can sometimes survive for weeks or even months. Giardia can be found in every region of the United States and around the world.

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How do you get giardiasis and how is it spread?

You can get giardiasis if you swallow the Giardia parasite (germ). Giardia—or poop from people or animals infected with Giardia—can contaminate anything it touches. Giardia spreads very easily; even getting tiny amounts of poop in your mouth could make you sick.

Giardiasis can be spread by:

• Swallowing unsafe food or water contaminated with Giardia germs
• Having close contact with someone who has giardiasis, particularly in childcare settings
• Traveling within areas that have poor sanitation
• Exposure to poop through sexual contact from someone who is sick or recently sick with Giardia
• Transferring Giardia germs picked up from contaminated surfaces (such as bathroom handles, changing tables, diaper pails, or toys) into your mouth
• Having contact with infected animals or animal environments contaminated with poop

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What are the symptoms of giardiasis?

Giardia infection (giardiasis) can cause a variety of intestinal symptoms, which include:

• Diarrhea
• Gas
• Foul-smelling, greasy poop that can float
• Stomach cramps or pain
• Upset stomach or nausea
• Dehydration

Symptoms of giardiasis generally begin by having 2 to 5 loose stools (poop) per day and progressively increasing fatigue. Other, less common symptoms include fever, itchy skin, hives, and swelling of the eyes and joints. Over time, giardiasis can also cause weight loss and keep the body from absorbing nutrients it needs, like fat, lactose, vitamin A, and vitamin B12. Some people with Giardia infections have no symptoms at all.

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How long after infection do symptoms appear?

Symptoms of giardiasis normally begin 1 to 2 weeks after becoming infected.

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How long will symptoms last?

Symptoms generally last anywhere from 2 to 6 weeks. In people with weakened immune systems (e.g., due to illness such as HIV), symptoms may last longer. Healthcare providers can prescribe the appropriate antiparasitic medications to help reduce the amount of time symptoms last.

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Who is most at risk of getting giardiasis?

Anyone can become infected with Giardia. However, those at greatest risk are:

• People in childcare settings
• People who are in close contact with someone who has the disease
• Travelers within areas that have poor sanitation
• People who have contact with poop during sexual activity
• Backpackers or campers who drink untreated water from springs, lakes, or rivers
• Swimmers who swallow water from swimming pools, hot tubs, splash pads, or untreated recreational water from springs, lakes, or rivers
• People who get their household water from a shallow well
• People with weakened immune systems
• People who have contact with infected animals or animal environments contaminated with poop

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How is giardiasis diagnosed?

Contact your healthcare provider if you think you may have giardiasis. Your healthcare provider will ask you to submit stool (poop) samples to see if you are infected. Because it can be difficult to detect Giardia, you may be asked to submit several stool specimens collected over several days to see if you are infected.

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What is the treatment for giardiasis?

Many prescription drugs are available to treat giardiasis. Although Giardia can infect all people, infants and pregnant women may be more likely to experience dehydration from the diarrhea caused by giardiasis. To prevent dehydration, infants and pregnant women should drink a lot of fluids while sick. Dehydration can be life-threatening for infants, so it is especially important that parents talk to their healthcare providers about treatment options for their infants.

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My child does not have diarrhea but was recently diagnosed with giardiasis. My healthcare provider says treatment is not necessary. Is this correct?

Your child may not need treatment if they have no symptoms, though it is important to consider that their poop may remain a source of infection for other household members for an uncertain period of time. However, if your child does not have diarrhea but does have other symptoms, such as nausea or upset stomach, tiredness, weight loss, or a lack of hunger, you and your healthcare provider may need to consider treatment. The same is true if many family members are sick or if a family member is pregnant and unable to take the most effective medications to treat Giardia. Contact your healthcare provider for specific treatment recommendations.

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Can I get giardiasis from my private well?

Giardia-contaminated poop can enter ground water through different ways, including sewage overflows, sewage systems that are not working properly, and polluted storm water. Wells may be more likely to be contaminated by poop after flooding, particularly if the wells are shallow, have been dug or bored, or have been covered by floodwater for long periods of time. Overused, leaky, or poorly maintained septic systems could contaminate nearby wells with germs from poop, including Giardia. Read more about testing your well.

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What can I do to prevent and control giardiasis?

To prevent and control Giardia infection, it is important to:

• Wash your hands with soap and water during key times, especially:
  • before preparing food or eating, and
  • after using the bathroom or changing diapers.
• Avoid eating food and drinking water that might be contaminated with Giardia germs.
  • Properly treat water from springs, lakes, or rivers (surface water) while backpacking or camping if no other source of safe water is available.
  • Avoid swallowing water from swimming pools, hot tubs, splash pads, and untreated water from springs, lakes, or rivers (surface water) while swimming.
  • Store, clean, and prepare fruits and vegetables properly.
• Practice safe sex by reducing your contact with poop during sex or avoid having sex several weeks after you or your partner have recovered from giardiasis.

For more information, see Prevention and Control.

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Can I get giardiasis from my pet?

The chances of people getting a Giardia infection from dogs or cats are small. The type of Giardia that infects humans is usually not the same type that infects dogs and cats. For more information, see Giardia and Pets.

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Giardiasis (beaver fever)

Last Reviewed: March 2023

What is giardiasis?

Giardiasis is an intestinal (bowel) illness caused by a microscopic parasite called Giardia. It is a common illness that causes diarrhea (loose stool/poop). The most common way people get sick with giardiasis is by swallowing contaminated water, but people can also get sick from contaminated food, surfaces, and objects.

Who gets giardiasis?

Anyone can become infected with Giardia, but those at greater risk include in children and staff in daycare centers, foreign travelers, and people who drink improperly treated water.

How is this parasite spread?

Giardia can infect people and wild and domestic animals. It is passed in the feces (poop) of an infected person or animal and may contaminate water or food. The beaver has gained attention as a potential source of Giardia contamination of lakes, reservoirs, and streams, but human fecal wastes are also play an important role in spreading the parasite. People become infected by accidently swallowing Giardia and can carry the parasite in their bodies from a few weeks to a few months. Spread of the parasite directly from one person to another may occur, especially in daycare centers, settings where handwashing practices are poor, or through oral-anal sex.

What are the symptoms of giardiasis and how soon do they appear?

People exposed to Giardia may experience mild or severe diarrhea (loose stool/poop), gas, stomach cramps, nausea (a feeling of upset in the stomach), or dehydration (loss of water in the body causing weakness of dizziness). Some people experience no symptoms at all. Fever is rarely present. Occasionally, some people will have chronic diarrhea over several weeks or months, with significant weight loss.

The symptoms may appear from 3 to 25 days after exposure but usually within 7 to 14 days.

How is giardiasis diagnosed?

Giardiasis is diagnosed by testing samples of your stool (poop). Sometimes, several different stool samples must be tested because the number of Giardia being passed in the stool, which varies from day to day, may be too low to detect from any single sample.

What is the treatment for giardiasis?

There are many prescription drugs that are available to treat giardiasis, however, some individuals may recover on their own in a few weeks without medication. Since diarrhea can cause dehydration, it is important to drink a lot of fluids when sick.

What can be done to prevent the spread of giardiasis?

Some important preventive measures are:

• Avoid ingesting untreated water from springs, streams, or lakes.
• Thoroughly wash hands with soap and water after toilet visits and handling soiled diapers.
• Thoroughly wash hands with soap and water after working with soil (landscaping, field work, gardening, etc.)
• Carefully dispose of sewage wastes so as not to contaminate surface water or groundwater.

causes, symptoms, signs, diagnosis (tests), treatment (diet), prevention in adults and children

Giardiasis is a protozoan invasion caused by the protozoan Giardia, which affects the small intestine. Shows indigestion. This pathogen was first described by the Czech doctor D. F. Lyambal in 1859year. Later, not only the parasite, but also the disease was named after him.

According to the WHO, about 200 million people worldwide are infected with Giardia every year. Most often this happens in Asia, Africa, Latin America. According to official data, up to 150 thousand infections with these protozoa are detected in Russia every year.

Giardiasis is often the cause of intestinal disorders in children of preschool and primary school age. In adults, it is mostly asymptomatic.

Causes

Giardia is the simplest microscopic unicellular parasite from the flagellate class. In the human intestine, it can be in two forms – vegetative and spore. Giardia reproduce by division and double in number every 10-12 hours. The habitat of vegetative forms is the upper part of the small intestine. Cysts are immobile, have an oval shape and are protected by a capsule. In this form, Giardia exists in the large intestine, as well as in the external environment. So they can remain viable for a long time.

The main causes of giardiasis are cysts entering the human body. This happens when eating unwashed vegetables and fruits, violating the rules of hygiene, using unboiled water. This route of transmission is called fecal-oral, since the source of the spread of giardiasis pathogens is an infected person who excretes cysts along with feces. Also, pets can be carriers of giardiasis, and flies and cockroaches act as carriers.

Provoking factors can be overcrowding, living in a polluted environment, poor condition of water supply and sewerage systems, non-compliance with sanitary and hygienic rules. A predisposition to the disease has been identified in children under 10 years of age, in people with malnutrition or dystrophy, congenital malformations of the biliary tract, diseases of the stomach and intestines with a reduced level of acidity, as well as in diets with a too low protein content.

Classification

Signs of giardiasis may be invisible in a quarter of all cases. This condition is called asymptomatic carriage. At the same time, the person himself is not sick, but he becomes a source of infection for others.

Half of all patients with giardiasis have a subclinical disease. They also do not have symptoms and do not consider themselves infected. Only diagnostics helps to identify the disease here.

And only in the remaining percentage of patients the disease has pronounced symptoms that can be acute, subacute or chronic.

Symptoms

Giardiasis often has erased symptoms and proceeds without pronounced clinical manifestations. With a typical form of the disease, the first symptoms begin to appear after the end of the incubation period, which lasts from 1 to 3 weeks, during which time the disease has no manifestations.

The intestinal form of the acute stage is characterized by:

1. Pain in the right hypochondrium, in the navel area and rarely in the lower abdomen.
2. Belching.
3. Feeling of heaviness in the left side of the abdomen.
4. Decreased appetite.
5. Frequent stools up to 3-5 times a day, which may be replaced by constipation.
6. Nausea.
7. Constant feeling of heaviness in the stomach.
8. Flatulence.

In young children, mushy stools are observed. The duration of the acute phase of the disease is 5-7 days, after which either recovery occurs or the infection passes into a subacute chronic course.

Hepatobiliary variant of giardiasis in women and men is manifested by pain in the area of ​​the liver and indigestion.

Skin manifestations can be very different and include pallor, the appearance of an icteric tint, dryness and peeling, and an allergic small rash. Stomatitis may develop in the mouth, and seizures or cracks appear in the corners of the mouth.

The syndrome of intoxication in giardiasis depends on how many cysts have entered the body, as well as on the duration and severity of the disease. Patients may complain of headaches, dizziness, sleep disturbance, decreased performance, irritability, emotional lability. Children may have tics, hyperkinesis, fainting.

Diagnostics

An analysis for giardiasis is the only reliable way to identify the disease, since it often proceeds without symptoms and has no specific manifestations.

The main list of tests for the diagnosis of giardiasis includes:

• Antigenic test for giardia, to detect them in the feces by ICA (immunochromatographic). It helps to identify acute or chronic forms of giardiasis, asymptomatic carriers, and is also an effective method for evaluating treatment.
• Determination of antibodies of classes A, M, G (IgM, IgA, IgG) to Giardia in the blood by ELISA (enzymatic immunoassay) for timely detection of infection.
• Express examination of feces for antigens to giardia, amoeba, cryptosporidium, which helps to diagnose parasitic diseases that occur without vivid symptoms.
• Microscopic method for examining feces for protozoa and helminth eggs.
• Analysis of feces for carbohydrates, which is prescribed for diseases of the small intestine with suspected infection with Giardia.

All other tests and studies for giardiasis are considered non-specific and are prescribed according to indications. These can be blood tests, urine tests, gastroscopy or ultrasound of the abdominal organs.

Treatment

Giardiasis requires complex treatment. Therapy of uncomplicated forms is carried out on an outpatient basis. When the diagnosis is confirmed, one of the antigiardia drugs is prescribed, which must be combined with the intake of cholagogues, as well as drugs that improve the intestinal microflora.

The chronic course requires long-term complex treatment, which will include not only medication, but also a diet for giardiasis, which limits the intake of carbohydrates. Etiotropic drugs help to cope with the simplest, and immunotherapy helps to increase the natural defenses of a person. Be sure to prescribe choleretic agents and probiotics to restore the intestinal microflora.

Modern medicine offers some clinical recommendations in the treatment of giardiasis. At the first stage, diet therapy and fasting days are prescribed, as well as the intake of choleretic, and, if necessary, antihistamines.

In the second stage, the patient takes special antiprotozoal drugs prescribed by a doctor. To get rid of Giardia, not one, but two courses are often prescribed.

At the third stage, multivitamins, enterosorbents, enzyme preparations, immunostimulants, phytotherapy are used.

Prophylaxis

After recovery, the risk of re-infection does not decrease, and relapses occur frequently. To completely get rid of parasites, repeated administration of drugs is often required. Dispensary observation is carried out for 3-6 months with a mandatory examination for parasites.

To prevent infection with giardiasis, you should not drink raw water even from the tap, follow all sanitary and hygienic rules, be sure to wash your hands before eating and after going to the toilet, do not eat unwashed vegetables, fruits, berries.

At the first suspicion of a disease, it is important to consult a doctor and undergo all the necessary studies to refute or confirm the diagnosis with further mandatory treatment.

causes, symptoms, signs, diagnosis, treatment, diet, prevention

Causes

Symptoms

Diagnosis

Treatment

Prevention

Giardiasis is a fairly common infectious disease caused by the protozoan Giardia. They got their name in honor of the Russian scientist who discovered and described their life activity – D.F. Lyamblya. However, Western colleagues consider the French researcher A. Giardou to be the discoverer of these microorganisms; for this reason, giardiasis is called “giardiasis” in the ICD-10 revision. Among domestic infectious disease specialists, such a diagnosis did not take root.

This disease is common in all countries of our planet, however, among the population of developing countries, the carriage of this infection is slightly higher and amounts to about 10% of all people. The reason lies primarily in poor-quality heat treatment of food products and the use of unboiled water. For this reason, in developed countries, the proportion of infected people does not exceed 3%. Giardiasis in women and men is approximately equally common.

Causes of giardiasis

The causative agent of giardiasis, giardia, is a parasite of the protozoan type. They are in one of their two main forms:

• vegetative form, in which they most often colonize the human intestinal lumen, they are mobile, can move in space, multiply by division;
• in the form of cysts – this is a kind of protective form in which they are outside the human body: in the soil, water. Cysts are immobile, do not divide, however, in this form, Giardia can remain alive for a long time.

Infection with this infection occurs by ingestion of food or water containing Giardia cysts. They get there after contact with a sick person who excretes them with feces (fecal-oral route, household contact).

Risk factors include overcrowding of the population living in one small area of ​​housing, poor awareness of elementary sanitary and hygienic standards. For this reason, the disease giardiasis is very common among children attending kindergartens and schools (prevalence in pediatrics reaches 30%).

Symptoms of giardiasis

After a person has swallowed food or water contaminated with Giardia cysts, they gradually enter the lumen of the duodenum 12. There they turn into vegetative forms, that is, active, capable of disrupting the villi of the intestinal epithelium and multiplying. From this moment begins the clinical picture of the disease itself giardiasis.

Depending on the severity of the symptoms and the localization of the pathological process caused by these parasites, the following forms of the disease are distinguished:

• the intestinal form is accompanied by symptoms of damage to the mucous membrane of the duodenum (duodenitis), small intestine (enteritis), stomach (gastritis) and several localizations at the same time;
• biliary-pancreatic form with damage to the gallbladder, biliary tract, pancreas;
• the astheno-neurotic form is accompanied by various neurotic disorders, which are provoked by a special toxin produced by lamblia;
• the mixed form is characterized by a combination of symptoms of various forms.

Clinical manifestations of giardiasis in adults and children begin after the incubation period, which is 1-3 weeks. During this time, the cysts turn into vegetative forms and begin to multiply. The disease usually begins with pain in the umbilical region, nausea, sometimes vomiting, belching, heaviness in the abdomen, and a feeling of bloating. Symptoms are not as pronounced as with food poisoning, sometimes they are confused with an exacerbation of chronic diseases of the digestive tract. At the same time, stool liquefaction is characteristic, its frequency increases up to 3-5 times a day, it becomes frothy or watery, periodically there are tenesmus – a pulling urge to defecate.

The acute period of the disease lasts up to a week, after which self-recovery occurs in half of the cases. However, in a number of people (children, people with weakened immune systems, impaired protein metabolism, after radiation or chemotherapy), the signs of giardiasis are significantly weakened over time, but do not disappear completely. They become chronic carriers of infection, which are especially dangerous for others. They are the source of the spread of this disease among healthy people. An important risk factor for chronic process is the simultaneous presence of helminths – ascaris, pinworms, trichinella.

With a long course of the disease, a person becomes asthenic, gradually loses weight, his skin becomes dry and pale. At the same time, the general allergic background very often increases – often patients (more often this occurs in children) begin to suffer from a polyvalent allergy to various food products and household items that have not previously caused such a reaction in them. Atopic dermatitis, eczema, bronchial asthma and other manifestations of hypersensitivity gradually appear or progress.

Patients with chronic giardiasis often develop various non-specific neurological disorders – asthenia, chronic fatigue, emotional lability, nervous tics.

Diagnosis of giardiasis

Diagnosis of giardiasis is carried out by an infectious disease doctor, in children, a pediatrician can prescribe an examination, but if necessary, he also refers to a pediatric infectious disease specialist or for examination in an infectious diseases hospital.

The difficulty in identifying this disease lies in the dim clinical picture and the vagueness of symptoms. Similar symptoms are present with a fairly extensive list of diseases of the digestive tract, including the hepato-biliary system with viral intestinal infectious diseases, with functional disorders. External examination also does not provide specific information, all symptoms are nonspecific (weakness, pallor and dry skin, vague abdominal pain, weight loss).

Therefore, if giardiasis is suspected, first of all, it is necessary to undergo a laboratory examination. The most informative is the detection directly of Giardia cysts or vegetative forms in the feces or in the duodenal contents during gastroscopy. The first method is the simplest, however, a negative result is often a false negative, so it is recommended to repeat it up to 5 times within a month. The second method is more reliable, but it is practically impossible for young children.

The most reliable test for giardiasis is the detection of giardia antigen in the feces by PCR or the detection of antibodies to these parasites in the blood. They allow you to unambiguously make or refute this diagnosis.

Among other things, general blood tests, urinalysis, coprogram, biochemical blood test, ultrasound examination of the abdominal organs can be prescribed.

Giardiasis treatment

The basis of the treatment of giardiasis is drugs from the group of antiprotozoal drugs. You should not try to purchase them yourself, they must be prescribed by a doctor, are prescription and are not released freely in a pharmacy. The dose, frequency rate and duration of the course are also prescribed by the doctor. If during the examination helminth eggs are simultaneously detected, then anthelmintic treatment is carried out.

Considering that when Giardia dies, toxins are released, sorbents are prescribed in parallel with taking antiprotozoal drugs. It is also possible exacerbation of allergic diseases, while recommending the use of antihistamines, topical steroids. In addition, at the recovery stage, the intake of probiotics, enzymes and multivitamins is indicated.

Clinical recommendations for giardiasis in the rubricator of clinical recommendations are not currently available. They are under development.

A special diet for giardiasis is another important aspect of treatment. It is necessary to strictly exclude foods that enhance the fermentation processes in the intestines – yeast bread, sugar, vegetables, and a temporary rejection of milk and dairy products is also shown. Periodically, you can arrange fasting days, tubages with dried fruits.

Prevention of giardiasis

The basis for the prevention of this disease is strict adherence to sanitary and hygienic standards, heat treatment of food and boiling water.

The author of the article:

Ivanova Natalya Vladimirovna

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