Lambliasis

Giardiasis (giardiasis, English name - Giardiasis) is a protozoal invasion, occurring more often as an asymptomatic carrier, sometimes with functional intestinal disorders.

ICD-10 code

A07.1. Giardiases (giardiasis).

Epidemiology of Giardiasis

The source of infection is a person who releases fungal cysts with feces. The possibility of human infection with strains of Giardia lamblia from animals (the pathogen found in dogs, cats, rabbits and other mammals) currently does not have sufficient evidence. The mechanism of infection is fecal-oral. The main transmission path is water. The degree of contamination by faeces of the environment is a decisive factor in the level of population affection with lambliasis. In children's institutions, the contact and everyday way of infection is of great importance. Group outbreaks are usually caused by fecal contamination of water, less often food. Lamblia cysts are found in the intestines of some insects (flies, cockroaches, flour mushrooms), which can contribute to their spread.

Giardiasis is ubiquitous, but the greatest damage to the population is noted in countries with a tropical and subtropical climate. In these countries lamblia is one of the most frequent pathogens of travelers' diarrhea. The disease is recorded in all age groups. Infectionists suggest that adults in endemic foci develop a certain protective immunity. In our country, most of the infected (70%) are preschool and primary school children. The most pronounced spring-summer seasonality, the smallest number of cases recorded in November-December.

[1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12]

What causes giardiasis?

Giardiasis causes Lamblia intestinalis (Giardia lamblia), which belongs to the sub-kingdom of Protozoa, the subtype Mastigophora, the order Diplomonadida, the family Hexamitidae.

In the cycle of development of the simplest, two stages are distinguished: the vegetative form and the cyst. The vegetative form is trophozoite 8-18x5-10 microns in size, pear-shaped. The posterior end is narrow and elongated, the anterior widened and rounded; ventral side flat, dorsal - convex. For trophozoite, a bilaterally symmetrical structure is characteristic. It has four pairs of flagella, two nuclei with karyosomes and a so-called sucking disk - a recess through which it is attached to the surface of the epithelial cell of the host's intestine. Lamblia is fed osmotically throughout the body, absorbing nutrients and various enzymes directly from the brush border. The maximum number of parasites is in the proximal part of the small intestine (initial 2.5 m), where the intensity of parietal digestion is the highest. Lamblias do not parasitize in the biliary tract, since concentrated bile has a harmful effect on parasites. Reproduction occurs by longitudinal division of trophozoite. The process of cyst formation takes 12-14 hours. The mature ovoid cyst is 12-14x6-10 microns in size. Contains four cores. Cysts excreted with feces are resistant to environmental factors: they remain viable up to 3 months in water at a temperature of 4-20 C. Like cysts amoeb, resistant to chlorine.

The pathogenesis of giardiasis

Symptoms of giardiasis depend on the infectious dose, the functional state of the gastrointestinal tract and the immune status of the body. Increasing the number of lamblia is promoted by foods rich in carbohydrates, resection of the stomach in an anamnesis and a decrease in the acidity of gastric juice. Prevents reproduction of lamblia protein diet. Trophozoites live in the duodenum, attached by means of suction discs to epithelial cells of villi and crypts. They do not penetrate the mucosa of the gut, but the suction discs form grooves on the microvillous surface of the epithelial cells. Parasites feed on products of parietal digestion and can multiply in the intestine in huge quantities. In places of parasitism of lamblia, mitotic processes and mature, fully functional cells are replaced by young, immature (frequent change of epithelium); as a result, the absorption of food components is impaired. These changes are reversible, after recovery from Giardiasis, the suction process is normalized. Giardiasis is often accompanied by intestinal dysbiosis, especially the number of aerobic microflora. The products of lamblia metabolism and substances formed after their death are absorbed and cause sensitization of the body. Morphological changes with giardiasis are characterized by a shortening of the papillae of the mucous membrane of the duodenum and jejunum, a decrease in crypt depth. 

Massive invasion of lamblia occurs with immunodeficiency, especially in children with primary hypogammaglobulinemia, selective IgA deficiency. Lamblias are capable of producing IgA proteases that destroy immunoglobulins of this class. Perhaps this is important in the formation of a persistent recurrent course of Giardiasis. Resistant to antiparasitic drugs.

Symptoms of Giardiasis

Lambliasis is distinguished latent (without clinical manifestations) and manifest. The vast majority of infected lambliasis symptoms are absent. The incubation period of giardiasis lasts from 7 to 28 days. Clinically manifested forms are relatively rare. The acute period lasts usually several days, after which the lambliasis often passes into a subacute or chronic stage with short-term exacerbations in the form of a loose stool and bloating, slimming, increased fatigue.

The most common symptoms of giardiasis with primary infection are nausea, anorexia, bloating and rumbling in the abdomen. The chair is quickened, offensive, fatty, foamy; possible vomiting, cramping pain in the epigastric region. This form of Giardiasis in hygienic conditions is stopped within a few days, it is well amenable to chemotherapy, but without a specific treatment it can take a long time. Some people have a predisposition to re-infection and persistent Giardiasis. In these cases, the disease giardiasis proceeds for months and years with periodic exacerbations in the form of gastroduodenitis, jejunitis, dyskinesia of the gallbladder. Known clinical forms with allergic manifestations in the form of urticaria with skin itching, attacks of bronchial asthma with mild eosinophilia in the blood. Children have frequent neurotic symptoms of giardiasis: weakness, fatigue, irritability, tearfulness, headaches. In tropical and subtropical countries, patients with giardiasis are registered with malabsorption syndrome.

Giardiasis can be complicated by intestinal dysbiosis.

Diagnosis of Giardiasis

Laboratory diagnosis of Giardiasis is to study feces or duodenal contents. In feces, cysts of lamblia are usually found. With diarrhea or after taking a laxative in feces, vegetative forms can also be found. To identify trophozoites, duodenal contents are examined. For diagnostic purposes, also smear-prints of the mucous membrane of the small intestine, biopsy material obtained at endoscopy. Using the ELISA, antibodies to lamblia antigens are detected .

Differential diagnosis of Giardiasis is carried out with helminthic invasions and other diarrheal infections. Consultative assistance is usually not required. Patients are treated out-patient.

[13], [14], [15], [16], [17], [18], [19], [20], [21], [22], [23]

Treatment of Giardiasis

Specific treatment of giardiasis is performed when lamblia is detected and the patient has clinical manifestations. For these purposes, use the following tablets against lamblia.

• Metronidazole. Inside, adults are prescribed 400 mg three times a day for 5 days or 250 mg three times a day for 7-10 days: children 1-3 years - 0.5 g per day 3 days, 3-7 years - 0.6 -0.8 g per day for 3 days, 7-10 years for 1-1.2 g per day for 5 days.
• Tinidazole is administered orally once, adults 2 g (if necessary, repeat), children - 50-75 mg / kg.
• Ornidazole is administered orally 1.5 g once a day (in the evening) for 5-10 days; For children with a body weight of up to 35 kg, the drug is prescribed at 40 mg / kg in a single dose.
• Nimorazole is administered orally 500 mg twice a day for 6 days.
• Nifuratel taken inside: adults 400 mg 2-3 times a day for 7 days, children - 15 mg / kg twice a day for 7 days.
• Albendazole. Inside adults, 400 mg twice a day for 7 days; Children - 10 mg / (kghsut), but not more than 400 mg, for 7 days. High lamblicidal efficacy of albendazole is shown, which can be a means of choice in the treatment of giardiasis in combination with intestinal nematodes. Alternatively, lamblia may also be treated.

Specific therapy for giardiasis ends with a control study of faeces.

Often infectious diseases are prescribed for a lambliasis.

Clinical examination

Clinical follow-up is carried out according to clinical and epidemiological indications: with prolonged persistent lambliosis, observation is recommended for up to 6 months with a double or triple parasitological examination.

[24], [25], [26], [27], [28], [29], [30], [31], [32]

How to prevent giardiasis?

Prevention of giardiasis is the same as with amebiasis and other infections with a fecal-oral mechanism of transmission of the pathogen.

Prognosis for giardiasis

Giardiasis has a favorable prognosis.