Causes of giardiasis

Giardia is what doctors call a type of parasite that many people know as lamblia. They are the causative agents of the disease. The causes of giardiasis and the ways of its transmission are what interests most respondents.

After all, only by knowing the cause and source of infection can you protect yourself and your loved ones, and in the event of infection, fight the disease.

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Life cycle of Giardia

Giardia cysts enter the human body orally (through the oral cavity), then they pass through the esophagus to the duodenum, where they undergo a procedure of vegetative, asexual, division. It is here that the individual passes into its mobile phase, called trophozoite. In the area of the small intestine, the parasites are fixed on the villi of its mucous layer, there they feed on substances obtained during the decomposition of human food products.

When they enter the large intestine, the life cycle of lamblia ends and begins again: giardia from active organisms turn into passive, immobile forms - they become cysts again. The large intestine is an unfavorable environment for lamblia to live in, so they "dress" themselves in a shell, which is its protection. From here, they leave the patient's body together with feces and are ready to infect others again. The life cycle of lamblia is closed. Up to nine hundred million cysts ready for infection are excreted together with feces, while ten to one hundred cysts are enough for lamblia to settle in the intestines of a healthy person. At the same time, their high vital activity can be maintained, in a preserved form, for a whole year, calmly enduring low (or high) temperatures, drying out. Only cysts are able to survive in such conditions; trophozoites released with feces die in such a climate.

How is giardia transmitted?

Having passed into the cyst phase in the large intestine, lamblia are excreted from the sick person together with feces. Once in the environment, giardia are ready to infect animals or other people again. To protect yourself and your loved ones, you need to know how lamblia is transmitted to a healthy organism. Doctors and epidemiologists voice three main ways of infection: contact-household, through food and through liquid.

• Giardia can enter the body of an adult or a child through unwashed or poorly washed vegetables or fruits.
• Lambliasis can be caused by poorly purified tap water or fruits and vegetables washed with it.
• Swimming in bodies of water (especially in still water): the vacationer involuntarily swallows water while swimming or diving.
• You can also become infected through household items: kitchen utensils, bed linen, bathroom accessories, children's toys.
• Bad habits can also cause infection, especially such as an involuntary desire to bite nails, pencils, and other objects. In almost one hundred cases out of one hundred, such “lovers” are diagnosed with giardiasis.
• There are isolated cases, but there are still cases of newborns becoming infected with cysts, which they received from their mothers.
• Despite the usually low temperature of spring waters, this organism feels great there. By drinking such water, a person “lets” pathogenic flora into his body.
• A small person can acquire these parasites during contact play with peers who are already carriers of giardiasis.
• Communication with our smaller brothers is not in vain. This also applies to pets, especially if they are outside.

How do you get infected with giardia?

It turns out that lamblia in its active phase (in the form of trophozoites) is not contagious, because it is not able to survive in the unfavorable conditions of the human (or animal) intestines and the environment. You can only become infected with cysts, an inactive form of lamblia, it is this phase of the lamblia state that is invasive. How do you get infected with lamblia? Invasion occurs either directly from a sick person to a healthy one, directly by contact-household means, or through dirty unwashed hands, in people who neglect basic rules of personal hygiene.

It should be noted that the main hosts of parasites are animals: cats, dogs, mice, deer and others. People mainly "catch this infection" from domestic and wild cats, which are the home and mobile carrier of parasites.

That is, if we generalize the available information, the main sources and carriers of parasitic microflora, called giardia, are infected humans and sick animals.

The size of this parasite is more than modest and it is almost impossible to see it with the naked eye. The parameters of lamblia are 18 by 10 microns (length and width of the parasite), this individual has four pairs of antennae.

How do you get infected with giardia? This question is quite easy to answer, the parasites enter the human body orally, that is, through the mouth. But how this happens depends on the environment in which the parasite is encountered.

Microorganisms can reach a person with liquid:

• This could be poor quality, poorly purified drinking water.
• When swimming in an open body of water, you can involuntarily swallow a little water. The risk of contracting giardiasis is especially high in stagnant, non-flowing water. It is also worth noting that giardia do not live in salt water, they are able to continue their life cycle and remain parasitically active only in fresh water.

With food:

• Unwashed vegetables and fruits or those washed with poor quality water.
• Unwashed egg shell.
• Raw meat or fish. Products have not been cooked sufficiently.

Contact route of infection with giardiasis:

• Through unwashed hands.
• Contaminated items.
• Poorly washed kitchenware.
• Bed linen and bath accessories.
• Using another person's personal hygiene items.
• The habit of biting nails, other objects and simply putting them in the mouth. This contingent has the highest percentage of infection with lamblia, it is almost equal to one hundred percent.

Giardia cysts

This is an inactive, immobile phase of Giardia, but it is this that allows the parasite to maintain its viability in difficult environmental conditions. Giardia cysts have an oval, slightly pear-shaped form. The geometric parameters of an individual can vary: from 10 to 16 microns in length, from 6 to 10 microns in width. The vegetative form of the parasitic microorganism is localized mainly in the small intestine, duodenum, bladder, and urinary tract. But after the parasite descends into the large intestine, it transforms into cysts - the microorganisms are covered with a kind of cocoon - a shell that protects them from the difficult conditions of the large intestine and the environment. It is the cysts that are excreted from the infected organism along with feces into the environment. When the cyst again enters a living organism, reaching the stomach, its shell dissolves and the lamblia enters another vegetative stage.

Cysts of the immature stage have two nuclei, which are located together with a spiral-shaped coiled flagellate apparatus in the cytoplasm, while the "mature" parasite is already the owner of four nuclei. When visually examining the microorganism through a microscope, its covering membrane is clearly visible, it has a clear limiting contour separating it from the protoplasm, which is a distinctive feature of this type of parasite from other protozoan intestinal microorganisms.

The cyst stage is endowed with dissemination functions. In a humid environment, in unfavorable climate conditions, individuals in this form are able to maintain their viability for two to two and a half months. In lake waters and water pipes, lamblia cysts can survive from one to three months if the temperature fluctuates from 4 to 20 °C. In hot summer, this parasite does not die in wastewater for up to three to four months. On the surface of food, these microorganisms can live for several hours, and in the case of a humid environment, even for several days. Lamblia are absolutely insensitive to chlorine, which is used to purify and disinfect drinking water. At the same time, heat treatment of the product can solve this problem, because the parasite dies at a temperature of 55 °C.

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Giardia cysts in stool

Diagnosis of giardiasis includes stool analysis and clinical blood testing. This is how antigens or cysts of giardia can be found in stool, and antibodies in human blood plasma.

It is quite problematic to find the vegetative form of lamblia in feces during examination; here, only cysts can be found. Cystogenesis is represented by two periods: the maturation period, which can last up to two weeks, and the time of maximum activity. It is difficult to detect lamblia in formed dense fecal mass, and it is also difficult to find them in warm feces, since the vegetative form of lamblia does not survive in such an environment, turning into cysts. Diuretics, effective diuretics, can increase the chances of detecting lambliasis. Their use stimulates intestinal peristalsis, which increases the likelihood of detecting the parasite. If there is a suspicion of infection, doctors usually prescribe two tests for confirmation, especially in the case of diarrhea.

The detection capabilities can be increased using a special medical device called Paraser, which concentrates parasitic microorganisms. The principle of its operation is quite simple. A formalin-ether mixture is introduced into a special small container (test tube). A small amount of feces is taken for analysis with a sterile spatula, a pea-sized amount is sufficient. The container is screwed on with a lid and the contents are mixed well. In this state, the sample can be stored at room temperature for 24 hours, but no more. Then the test tube is placed in a medical centrifuge and spun at high speed (about 3000 rpm). Centrifugal forces force the cysts to pass through the filter and accumulate at the bottom of the test tube, in its conical compartment. The concentration of microorganisms is highest in the upper layers of finely dispersed sediment.

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Are Giardia dangerous?

Almost a third of the world's population are carriers of such a parasite as giardia, and do not even know about it. This microorganism has "chosen" the small intestine of humans and animals for life (it is animals, mainly representatives of the feline family, that are the main hosts of this parasite). Getting into the human body, giardia do not cause it any discomfort. Hence the natural question arises - are giardia dangerous? Doctors answer it unequivocally. If the body of an adult or a child has a sufficiently high immune defense, then the body of a patient who has been subjected to aggression from harmful microorganisms is able to cope with the aggressor on its own.

The only officially registered disease associated with giardia is diagnosed by doctors as pathological changes to which the duodenum is subject. It is called giardiasis enteritis. In most cases, this disease goes away on its own. If the immune system is weakened and is unable to adequately respond to aggression, the colonization of the patient's body with pathogenic flora can lead to intoxication.

In rare cases, giardiasis can cause chronic enteritis. This disease is expressed in a constant sluggish inflammation process, which is localized in the small intestine. Ultimately, such development of the disease leads to complete or partial atrophy of the intestinal mucosa. In this case, the following parts can be affected: the duodenum (the inflammatory process in this area is called duodenitis), the ileum (ileitis) or the small intestine (jejunitis). However, inflammation mainly affects the mucosa of the entire intestine, so colitis or gastritis can also join here.

Types of Giardia

Doctors distinguish two periods of the lamblia development cycle: immobile or cysts, and mobile or the vegetative stage. Active and inactive types of lamblia form the complete life cycle of the parasite.

The first stage is immobile and is called a cyst. During this period, the individual has parameters of approximately 12 microns in length and 9 microns in width. Thanks to its protective shell, the parasite is able to endure the complex climatic and biochemical features of the intestinal biome and the environment without any consequences. Under this shell is a trophozoite that has not yet fully formed. It is in this form that lamblia is released from the affected organism and waits for a convenient opportunity to get into the healthy organism of the "new host". That is, it is thanks to cysts that the microorganism is able to spread and infect ever larger territories.

Trophozoite is an active, vegetative phase in the development of lamblia. After the cyst enters the stomach, under the influence of gastric secretion, the shell splits. The renewed individual enters the active phase. During this period, it has a pear-shaped form and is slightly larger in size than in the cyst period. It is in this form that lambliasis causes maximum damage to the body. Giardia move, actively feeding on food decay products, while they are able to disrupt the cellular structure of the intestinal mucosa. As a result of their activity: there is a malfunction in the intestines, signs of dysbacteriosis appear, the likelihood of penetration of pathogenic microflora increases. In this form, they grow and go through a period of direct division (mostly this process occurs in the duodenum). The life cycle is determined by several divisions.

Intestinal lamblia

Giardia intestinalis - this is the Latin name for the intestinal lamblia - a type of flagellate protozoan microorganisms that are the causative agents of a parasitic disease that affects the intestines of humans, many birds and other mammals. This type of parasite is also called Lamblia intestinalis, Giardia lamblia or Giardia duodenalis.

This protozoan parasite is called "traveler's diarrhea" because it is found in about five percent of people returning from a tourist trip, especially after visiting tropical countries. Depending on the biophysical characteristics of the infected person, the disease may be asymptomatic in one case, while in another the manifestations may be so significant that a severe form of diarrhea with malabsorption is observed.

The "habitat" of this parasite is so vast that it is difficult to point out a place on the globe where its cysts have not been found. In some areas, the population's infection with this parasite, especially young children (under five years old), approaches one hundred percent. Giardia, under various conditions of infection and the level of the human immune system, can show the following symptoms:

• Refractory diarrhea or its acute form of manifestation.
• Flatulence, accompanied by rumbling sounds in the intestines.
• Malabsorption, manifested by watery stools.
• Spasmodic pain symptoms in the abdominal area.

But in the vast majority of cases, the disease is completely asymptomatic. This makes diagnosis very difficult.

Lamblia hepatica

Giardiasis is a very frequently diagnosed protozoan pathology. Lamblia hepatica often does not manifest any symptoms, but if detected, it always indicates the presence of giardiasis.

Symptoms of Giardia in the liver:

• Belching.
• Bloating and an unpleasant cacophony of sounds in the intestines.
• A decrease in appetite is observed.
• Permanent coating on the tongue.
• Diarrhea alternates with constipation.
• On palpation, enlarged liver parameters are observed.
• Systematic pain symptoms in the navel and lower abdomen.
• A feeling of heaviness and fullness in the stomach.
• Pain under the right rib.
• Very rarely, a sharp decrease in blood pressure (hypotonic crisis) may be observed.
• Pre-fainting, fainting condition.
• Heart rhythm disturbance.

When the disease becomes chronic, almost all patients have increased pallor of the skin. The skin on the soles and palms, on the contrary, acquires a red-terracotta hue. As the disease progresses, the color begins to approach pink, the epidermis loses moisture, showing dry skin. The patient begins to lose weight, signs of an allergic reaction appear (urticaria, itching, rash). If chronic giardiasis affects a baby, it can have more global consequences: the child begins to lag behind in development.

How to detect giardia?

This parasitic infectious disease is often diagnosed in both adults and children. The incidence of young children (up to five years of age) sometimes reaches a figure of more than 72%. To understand how to identify lamblia, it is necessary to know that lamblia in the form of cysts are excreted from the body of a sick person mainly with feces. After entering the external environment, the parasite does not lose its ability to infect for up to 70 days. This parameter depends on the climate surrounding the cyst. It is also necessary to know the main symptoms of this disease. Difficulty may arise if the infection occurs without any special symptoms, which is what usually happens.

But it is still worth understanding what discomfort should make a person see a doctor to undergo testing for giardiasis. A person affected by giardia may experience nausea, painful spasms in the abdominal area, problems with stool: diarrhea alternating with constipation of feces. Small patients suffer from colic that bothers them. Such symptoms are inherent in a fairly wide range of diseases associated with pathological damage to the gastrointestinal tract. In this case, only a certified doctor can make a correct diagnosis, and you should make an appointment with him if the discomfort described above occurs.

The first thing a specialist does is send the patient for a stool test. Before the test, it is necessary to strictly follow the advice given by the doctor. Due to the specific features of the life cycle of lamblia, this test cannot be unambiguously indicative, and if there is a parasite in the body, the test may not show this. Therefore, if suspicions remain, the doctor prescribes a repeat test and additional tests.

In parallel with the stool test, serological blood testing is prescribed. This requires some preliminary preparation, recommendations for which will be given by the doctor.

Another test for the presence of Giardia is bile testing. This method of research is technically more complex, so it is prescribed less often than the previous studies. If necessary, an intestinal biopsy is also performed. All this together makes it possible to make a correct diagnosis.

Antibodies to Giardia

In addition to feces, the patient's blood is also submitted for testing, which is taken from a finger or vein. For this analysis, this is not significant. To find antibodies to lamblia IgA, IgM, IgG, an enzyme immunoassay is used, for which 20 microliters of serum are sufficient (for comparison, one drop of blood has a volume of approximately 50 microliters). Initially, a negative control is taken and its value is used to calculate the optical density of diagnostics (ODD). If the obtained value is greater than ODD, we can talk about a positive response to the presence of lambliasis. In this case, to avoid error, a repeat analysis is carried out. The ratio of the result figure to the exceeding ODD indicator is called the positivity coefficient (K pos). This coefficient is the controlled parameter in the process of therapeutic therapy.

• If K pos falls within the range of values from 0.85*OPd to 1*OPd, this answer is considered questionable and implies a repeat study after three weeks. Such a result can be obtained if the antibodies only increase their quantitative component, they lose their previous quantity, or the effect of some medications is observed.
• If the K pos is diagnosed to be less than 0.85*OPd, then the test result is said to be negative.

It is worth noting that cellular and humoral (or antibody-based) immunity in a patient after recovery can be observed for two to six months. This indicator depends on the patient's condition and living conditions. Re-infection can occur after the "strength" of antibodies runs out. People with a history of gamma globulin deficiency in the blood (hypogammaglobulinemia) or a decrease in immunoglobulin A are at a higher risk of infection. Such a contingent of patients has a high chance of acquiring chronic giardiasis.

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Giardia antibody titer

Innovative research, a test used in the qualitative diagnostics of giardia in the patient's body, and, subsequently, monitoring the effectiveness of treatment - titer of antibodies to lamblia. It is assumed that this parasite is a provoking factor for more than twenty percent of acute intestinal diseases. The incubation time of lamblia from the moment of infection can be from one to three weeks.

In most patients, the disease is latent, i.e., without showing any symptoms. Clinically expressed symptoms divide the disease into two stages. The acute form of the disease lasts for five to seven days and can subsequently become chronic. This type of development is typical for preschool-age children. A relapse of the lesion is observed.

Giardiasis is quite difficult to diagnose. Traditionally, they try to detect them by analyzing the patient's feces or blood. The titer of antibodies to Giardia is indicated for use:

• There are suspicions of infection of the human body by parasitic microorganisms, in particular, giardia.
• If small patients suffer from frequent allergic reactions, dermatological diseases, gastroduodenitis.
• The titer is used as a control measure for the effectiveness of treatment.
• Epidemiological nature of the study.

To minimize the side effects of other factors on the results of the study, it is necessary to adhere to certain preparatory rules.

• Before taking a blood test for giardia, it is better not to eat anything, you can only drink plain water.
• The day before the examination, it is recommended to exclude or at least reduce the amount of fried and fatty foods consumed.
• You must not drink alcoholic beverages 24 hours before the planned event.
• Avoid heavy physical activity.

The following factors may influence the results of the study:

• Hemolysis test, presence of chyle in the blood of an infected patient.
• Medical therapy, including the use of immunosuppressants or cytostatics.
• Conducting or following radiation therapy.

How to evaluate test results?

• If the title shows a result below 1/100, the test for giardiasis is negative.
• If the title shows a result of 1/100 or higher, the test for giardiasis is positive.

If the test result is positive, this means that the patient is infected with giardiasis at the present moment or was infected in the recent past.

If the test result is negative, this indicates the absence of infection or in the case of seronegative patients.

Giardia antigen

This test is performed for rapid testing of the patient's stool for the detection of Giardia lamblia (Lamblia intestinalis). A positive response to the immunochromatographic and enzyme immunoassay for the presence of lamblia antigen, which are mainly used recently, indicates the presence of giardiasis in the body. This analysis has a fairly high sensitivity level, which is about 96%. The presence of 10-15 parasites in the samples is enough for the test system to give a positive response.

This technique not only allows detecting Giardia cysts in the patient’s blood serum, but also dividing them into specific antibodies of different classes.

• The IgM class of lamblia antigen appears in the serum of the affected organism on the tenth to fourteenth day after infection and is an indicator of the disease.
• Subsequently, IgG antibodies begin to be diagnosed, which are present in the plasma throughout the entire duration of the disease. After an effective course of treatment, antibodies of this class are observed in the blood for another one to two months after the end of therapy. After two to six months, IgG antibodies completely disappear.
• Anti-lambliasis secretory antibodies of class IgA play an important role in suppression and elimination of giardia, intestinal sanitation. It has been confirmed that patients with cellular immunodeficiency suffer more from pathological damage than individuals with a history of selective IgA deficiency.

What does giardia look like?

Before we take a closer look at the structure of Giardia, we must remember that the life cycle of this protozoan parasite is divided into two periods of its existence: vegetative and cysts. In each of these periods, the structure of Giardia has its own characteristics. What do Giardia look like in each of these periods?

The vegetative active period of development is represented by trophozoites, which resemble a small pear in their outline. Inside this outline, two nuclei are clearly visible, which, in combination with the parabasal body of the protozoan, resemble a funny face. The parasite is equipped with eight flagella located on its pear-shaped "head". It is with their help that it moves. Nutrition occurs over the entire surface by diffusion. Reproduction is subject to the laws of the simplest division of the mother cell into two daughter cells.

Now let's see what Giardia look like in the immobile cyst stage. The shape of this period changes somewhat and approaches an oval. The parameters of the cyst are somewhat smaller than its size in the trophozoite form and, unlike the latter, they show complete immobility. A fairly thick shell is designed to protect the more vulnerable internal contents of the cyst from an unfavorable environment. The "shell" lags somewhat behind the contents - and this is what allows us to distinguish Giardia from other protozoa. In contrast to the two-nuclear trophozoite, the cyst has four nuclei and has a suction apparatus, as well as a basal body.

Is giardia curable?

Giardiasis is an unpleasant but not fatal disease. However, this does not mean that it is not necessary to stop the problem. So, are giardia treated? Drug therapy is not used immediately. It is necessary to cleanse and prepare the body for antiprotozoal treatment beforehand, since anti-giardiasis drugs can provoke acute anaphylactic and toxic responses from the body. It is also possible to get an intensification of the clinical picture of the disease.

Not the least important factor during antiprotozoal therapy is nutrition. Failure to do so may result in relapses of giardiasis immediately after the end of the treatment course.

First, it is necessary to determine which products are not recommended for consumption during treatment:

• Foods with a high content of easily digestible carbohydrates.
• Fatty, spicy, smoked and fried foods.
• Fast food products.
• Sausages.
• Pasta.
• Canned food products.
• Bakery and confectionery products.
• Whole milk, semolina porridge.

The diet must include:

• Porridges cooked in water. Rice and buckwheat are best.
• Fermented milk products: yogurt, fermented baked milk, kefir.
• Any vegetable oil that has not undergone a refining process.
• Dried fruits.
• Berry and fruit compotes, kissels and fruit drinks.
• Low starch vegetables.
• Baked apples.

The first stage of therapy can be called preparation for treatment. During this period, diuretics (choleretic agents) are prescribed. They stop inflammation, promote increased excretion of fluid, and with it toxins from the patient's body. There is an active outflow of bile, simultaneously cleansing the bile ducts. Cholekinetics are also prescribed, which promote increased activity of the gallbladder. This division is quite conditional, since modern drugs in this area are usually supplied with both characteristics. For example, odeston, oxaphenamide, choleritin, barberry-based drugs, pituitrin, cholecystokinin, mannitol, sorbitol, xylitol.

Oxafenamide. The drug is administered orally after meals. The dose of the drug is 0.25 - 0.5 g, taken three times a day. The duration of the course is determined by the attending physician, but on average it is 15-20 days. If necessary, after a short break, the drug can be resumed.

It is not recommended to take Oxafenamide for patients who suffer from hypersensitivity to chemical compounds of this group, if the patient has a history of invasive liver cirrhosis, ulcerative manifestations in the digestive system, in the case of acute hepatitis, obstructive jaundice.

Antispasmodic drugs are prescribed that relax muscle spasms, for example, drotaverine, besalol, datiscan.

Besalol. The drug is administered orally one tablet two to three times a day. The drug should not be prescribed to patients whose medical history is burdened with hypersensitivity to the components of the drug, hypertrophic changes in the prostate gland, occurring with impaired urine outflow, gastrointestinal bleeding.

Enterosorbents are administered, which cleanse the body, for example, activated carbon, which is taken 0.25 - 0.75 g three to four times a day. Sometimes the dose is calculated - one tablet per 10 kg of the patient's weight.

Enzymes are also used to normalize the enzymatic component of the intestine (prescribed based on the results of a coprogram).

The basic stage of therapy includes the introduction of strong antiparasitic drugs and antibiotics. These are the following medications: metronidazole, chloroquine, tinidazole, furazolidone, paromomycin, tiberal, macmiror and others.

Tinidazole is prescribed once in the amount of 2 g, which corresponds to four tablets. The intake is carried out forty to fifty minutes after a meal. Or 0.3 g daily for seven days. In case of persistent course of the disease and residual manifestations, such courses are necessary from six to seven.

Contraindications to the drug include hematopoiesis pathology, changes in the central nervous system, the first trimester of pregnancy, and the lactation period.

The general treatment protocol is prescribed by the attending physician based on the examination results. The use of drugs allows for an improvement in the patient's condition already during the first week of the treatment course. After seven to ten days, the course must be repeated regardless of the preliminary positive result. This will reduce the risk of relapse. If necessary, several such courses are carried out, with the greatest effect being achieved by using different drugs for each stage of treatment.

To consolidate the obtained effect, practice:

• Eating the foods recommended above.
• Use of herbal remedies: decoctions of birch buds, bearberry seeds and others.
• Taking medications that normalize intestinal microflora.

In such a situation, alternative medicine recipes will also help:

• A mixture of fresh plantain leaves crushed in a blender and honey taken in equal proportions works effectively. The finished composition is kept in the refrigerator and consumed one tablespoon 30 minutes before breakfast for a month. This composition not only copes well with parasitic microflora, but also activates the body's defenses. •
• Coconut has also proven itself to be excellent. It needs to be split and the milk drained. Then grate the pulp and take it on an empty stomach for three days. •
• An effective tincture is made from one hundred unripe walnuts placed in a liter of vodka. Keep this mixture in a cool, dark place for 14 days, shaking it periodically. Filter the liquid and drink a teaspoon before each meal.

Giardiasis is a rather complex and veiled disease. The causes of giardiasis are extensive, but they need to be known in order to effectively combat the problem and be able to reduce the risk of infection of the human body by parasitic microorganisms.