Overview
Intestinal Pearly Flagellosis, also known as Giardiasis, is a disease of diarrhea, wasting and malabsorption of nutrients caused by Pearly Flagellates. It is found all over the world, especially in warm and humid areas, with a worldwide infection rate of 1% to 30%, and a higher infection rate of 50% to 70% in children. In our country is also very widely distributed, most of the scattered incidence, but in special circumstances, often due to tourism and infected with intestinal pear-shaped flagellosis caused by outbreaks of epidemic, so there is a “traveler’s diarrhea,” said.
Causes
Pear-shaped flagellates are unicellular protozoa with a simple developmental process, including two life stages: trophozoite and encapsulation. Generally, only the encapsulation can be found in normal hardness feces, and the trophozoites can be found in diarrhea. The mode of infection is mainly due to the ingestion of mature tetranucleate cysts, the swallowed cysts by the action of gastric acid, in the duodenum decapsulated into trophozoites, the resistance of the cysts is very strong. According to statistics, a diarrhea feces trophozoites can be more than 14 billion, in a normal feces can be 300 million encapsulated, another person statistics a day and night can be discharged encapsulated 900 million.
Symptoms
After human infection with Pearly Flagellosis, the incubation period is 1~2 weeks on average, the longest one is 45 days. Quite a number of people do not show any clinical symptoms, and become carriers of worms, there are those who show mild symptoms, and there are also those who show serious symptoms. According to the urgency of the onset and duration of the disease, the disease is divided into acute, subacute and chronic.
1. Acute infection
The disease often manifests as explosive diarrhea, watery stools, foul smell, bloody stools and mucus stools are rare, and can be distinguished from amoebic and bacillary dysentery. Stools 3 to 10 times a day or more, accompanied by epigastric or periumbilical pain, anorexia, nausea, vomiting, abdominal distension is obvious. Microscopic examination can find pus cells, erythrocytes and trophoblasts or encapsulated generally acute phase lasts 3 to 4 days.
2. Sub-acute or chronic infections
The manifestation of intermittent loose stools, lasting months or years. Children may suffer from malnutrition, anemia, and developmental disorders if the disease is not cured for a long time. If parasitized in the biliary system, cholecystitis or cholangitis can occur. If not treated in time, the disease will develop into a chronic condition, which is characterized by periodic loose stools, recurrent episodes, foul-smelling stools, and the duration of the disease can be up to several years.
3. According to the onset of symptoms can be divided into systemic symptoms, biliary system symptoms and gastrointestinal symptoms.
(1) Systemic symptoms
(1) Neurological symptoms such as insomnia, headache, fatigue, dizziness, black eyes, sweating, increased nerve excitability, hyperreflexia, etc. are more common.
(2) Thyroid dysfunction It has been found that some (15.5%) patients with intestinal pyriform flagellosis have altered thyroid function, in which hyperthyroidism accounts for the majority, basal metabolism is increased by 16% to 20%, and can be increased by 30% in some patients, and thus the symptoms of hyperthyroidism will be produced as well.
(2) Biliary system symptoms
Intestinal pear-shaped flagellosis parasitizes in the biliary system, which can cause cholecystitis and cholangitis. The main symptoms are pain in the upper abdomen, loss of appetite, dyspepsia, nausea, belching, burning sensation in the stomach, enlarged liver and spleen with pressure pain, which is aggravated by eating greasy food, and sometimes jaundice may appear.
(3) Gastrointestinal symptoms
(1) Duodenitis type There is ulcer-like pain like duodenum, accompanied by nausea, hypotension, etc. X-ray examination mostly shows deformation of the bulb and even signs of ulcer. The above symptoms can be eliminated after anthelmintic treatment.
(2) Acute or chronic appendicitis type The symptoms are similar to those of general appendicitis. The resected appendix is characterized by inflammatory lesions, sometimes ulcers are seen in the mucosa, and a large number of trophozoites can be found between the villi.
(3) Colitis type The main symptoms include dull pain in the abdomen, aggravated by paroxysms, accompanied by nausea, vomiting and diarrhea, which is often misdiagnosed as dysentery.
(4) Rectosigmoiditis type is the same as general rectosigmoiditis. Sigmoidoscopy, can be seen diffuse congestion, edema, severe round ulcers, ulcer surface covered with exudative pseudomembrane.
Examination
The detection of trophozoites or capsules in the feces is a simple and reliable diagnostic method commonly used in clinical practice.
1. Fecal examination
It is the most commonly used method and is divided into two categories: direct smear method and concentration method.
(1) Acute or intermittent episodes During this period, the feces of the patients are mostly watery or mushy, and the trophozoites tend to disintegrate because they die easily. Therefore, fresh specimens should be taken to make wet smears (in saline), and in order to maintain the vitality of the trophozoites, the specimens sent for examination should be kept warm. Under the microscope, the trophoblast can be seen in the active movement state, according to which the diagnosis can be made.
(2) subacute or chronic phase of the patient in this period of feces has been basically shaped, containing the capsule, the general use of 2% of the iodine solution can be diagnosed by direct smear method. In order to improve the detection rate, can also be used zinc sulfate floatation or aldehyde – ether concentration and other methods. Due to the intermittent discharge of the capsule, the use of every other day, three consecutive check method, can greatly improve the detection rate.
2. Small bowel fluid examination
Clinical suspicion of the disease and feces are not detected when the worm can be duodenal drainage or cholangioscopy. However, this method is more painful and not easy to be accepted by the patients, and now the capsule method is mostly used.
3. Small intestine biopsy
For the suspicious cases that both feces and small intestinal fluid examination show negative, endoscopy can be used to extract mucosal tissues near the flexural ligament of the small intestine (ligament of Treitz), and then perform the preliminary examination of compression slice or fixation, and then stained with Gram’s (Giemsa) staining. Pear-shaped flagellates stained with purple, intestinal epithelial cells pink, according to which the two can be distinguished. This method is simple, easy to implement, effective, and easily accepted by patients.
4. Immunodiagnosis
(1) Enzyme-linked immunosorbent assay (ELISA) is highly sensitive and specific in detecting intestinal pear-shaped flagellosis, and the positivity rate of immunoglobulin G (IgG) antibody is 71.1% to 98.9%.
(2) Indirect hemagglutination (IHA) test is a widely used serological diagnostic method, with high sensitivity, simple operation, rapid, without complex equipment and special reagents, it is a better method to diagnose Pityriasis intestinalis, with a positive rate of 73.4%.
(3) Indirect Fluorescent Antibody Test (IFAT) The positive rate is higher than that of IHA, reaching 66%~97%, and the positive rate of IFAT in symptomatic people is higher than that of asymptomatic people, which has a strong specificity in the diagnosis of intestinal pyriform flagellosis, without false positive reaction.
(4) Convection immunoelectrophoresis (CIE) test is an effective method for detecting antigens in the feces of patients with entero-pearly flagellosis, which is rapid, accurate, simple, and has a high specificity, but its sensitivity is lower than that of ELISA and IFAT.
Diagnosis
This disease needs to be differentiated from other causes of diarrhea, such as bacterial diarrhea and amoebic enteropathy.
Intestinal amebiasis should not be ignored because of the lack of specific clinical manifestations of amebiasis. The disease has a slow onset, mild symptoms of toxicity, easy to recur, intestinal symptoms or dysentery-like diarrhea of varying severity, so the intestinal disorders or dysentery-like diarrhea and the etiology has not been clearly defined, or by sulfonamides, antibiotics, no effect of treatment is suspected of this disease. Before diagnosis, fecal examination: ① live trophozoites examination method; ② encapsulation examination method.
Treatment
The treatment of this disease mainly adopts drug therapy, in addition to effective drug therapy for acute patients, oral or intravenous rehydration should be used to avoid excessive loss of body fluids.
1. Metronidazole
Oral, 10 days for a course of treatment, can be repeated after 7 days of rest.
2. Metronidazole is taken once, the cure rate reaches 88.8%, and the cure rate of those who are treated with the drug twice is close to 100%, with few side effects.
3. Nitromorphone
Adults 2 times a day, 5 days for a course of treatment, children’s dose is reduced.
4. Furazolidone
Furazolidone is an effective anti-Pearly Flagellate drug, oral dose: adults four times a day; children, divided into four times, served for 7 to 10 days, the cure rate can reach 85% to 90%.
5. Baronomycin
This product is a kind of non-intestinal absorption aminoglycoside, its efficacy is lower than other drugs, but because of its intestinal absorption is very low, toxic side effects are small, commonly used in the treatment of patients infected with Pearly Flagellates during pregnancy.