pouch ciliate disease
Introduction
Introduction to pouch ciliate Small bag ciliate disease (balantidiasiscoli) is a common parasitic protozoal disease caused by colonic ciliate (balantidiumcoli) parasitic in human colon. Clinical manifestations include abdominal pain, diarrhea, mucus pus and bloody stools, urgency, and fever. Chronic protracted patients It is characterized by alternating constipation and diarrhea or periodic diarrhea. At present, 22 provinces, municipalities and autonomous regions in China have confirmed the existence of this disease. basic knowledge The proportion of illness: this disease is rare, the incidence rate is about 0.007%-0.008% Susceptible people: no specific population Mode of infection: digestive tract spread Complications: peritonitis appendicitis
Cause
The cause of pouch ciliate disease
(1) Causes of the disease
Colonic pouch ciliates were first discovered by Malmsten in 1857 in the feces of 2 patients with acute dysentery. Subsequently, Leu Kart also found the worm in the large intestine of the pig in 1861. In 1862, Stein classified it into the genus of the genus and named it the colonic pouch. Ciliate, its taxonomic status is protozoa subfamily, cilia, mobilization, vestibular subclass, hairy mouth, genus, genus, genus Balantidium coli.
Form
The colonic pouch ciliate is the only ciliate that is found to be parasitic in the human body. It is also the largest protozoan parasitic in the human body. Its life history includes two basic forms: trophozoites and cysts.
(1) The trophozoite is round or oval, colorless or transparent, slightly grayish green, and the size is about 30-200 m × (25-120) m. The ventral surface is slightly flat, the back is raised, and the surface of the worm is flawed. Shaped uplift and groove-like depression, extending from the front to the rear end, the surface of the braided ridge is wrinkled, the grooved depression is located between the two ridges, the surface cilia are extended from the small groove to the outside, and the cilia swing can make the worm move back and forth. The surface of the worm has a surface covered with a transparent outer material, the inner side is the endoplasm, the front end of the worm body is slightly pointed, and the ventral surface has a food bubble formed by the invagination of the membrane. The food is digested in the bubble, and the residual substance passes. The small, inconspicuous triangular cytoplast of the worm body is excreted in vitro. The trophozoite has an electron dense body. There are two contractile vacuoles in the cytoplasm to regulate the osmotic pressure. The cytoplasm also contains polysaccharide granules. Bubbles, etc., mitochondria are distributed in the outer circumference of the worm.
(2) The capsule is round or oval, and the size is about 40-60m. The wall of the capsule is thick and transparent, light yellow or light green. The active trophozoite can be seen in the fresh capsule. The capsule has strong resistance to the external environment. The force can live for 2 weeks to 2 months at room temperature, and it will die after 3 hours in direct sunlight. It is also resistant to chemical drugs and can live for 4 hours in 10% formaldehyde solution.
2. Life history
In the infection stage of the worm, the person is infected by swallowing the food or drinking water contaminated by the capsule. The cyst is in the digestive tract and is affected by the digestive juice. The worm body is turned into a trophozoite and the trophozoite falls into the large intestine. Intestinal food residue, intestinal wall cells and bacteria are used as foodstuffs. The trophozoites are mainly propagated in the intestine by the transverse splitting method. They can also be propagated by bud reproduction. Some trophozoites are affected by the dehydration of feces, and the worms become round and secreted. The wall of the capsule wraps around the worm body to form a capsule and is discharged with the feces. The trophozoite in the intestinal lumen of the pig can be formed into a large number of sacs, but the sac is rarely formed in the human intestinal lumen. In addition, the nucleus does not split when the sac is formed. When the digestive tract is decapsulated, a capsule can only produce one trophozoite.
(two) pathogenesis
Most people think that the colonic ciliate is pathogenic. When the human body suffers from chronic diseases, malnutrition, and intestinal dysfunction, the worm can invade and cause disease. It takes a while for the insect to invade the human body to adapt to the intestinal tract. Symbiotic flora, once adapted, can rapidly multiply, some bacteria in the intestine such as Klebsiella, Staphylococcus aureus, Enterobacter, and other parasites have the effect of promoting the growth of the insect-induced lesions, colonic pouch ciliates Invasive intestinal tissue must rely on the mechanical movement of cilia and secretion of hyaluronidase. The worms penetrate the interstitial cells through hyaluronidase and penetrate into the intestinal tissue. Glycogen has also been isolated from severely infected pig manure. Decomposing enzymes and hemolysin, the insect body causes colonic mucosal inflammation, necrosis and ulceration by means of the above factors, and can be followed by bacterial infection, thereby aggravating mucosal lesions. The pathological changes are similar to intestinal lesions caused by amoeba in the tissue. The site is mainly in the cecum and sigmoid colon, occasionally involving the end of the ileum and the appendix. In some cases, the worm can invade the mesenteric lymph nodes, liver and lungs. Membrane, genitourinary tract, etc., intestinal mucosa congestion, edema, and sometimes there is a point of bleeding at the tip of the needle. The early intestinal mucosa of the lesion may have a crater-like ulcer with a diameter of several millimeters, gradually expanding and merging, forming an ulcer with a small edge and a large edge. Different from the amoebic ulcer, the ulcer formed by this disease has a slightly larger opening and a short neck. The bottom of the ulcer is generally located in the submucosa, but a large number of trophozoites are also seen in the peripheral intestinal mucosa. The mucosa of the ulcer can be normal or edematous. And have lymphocytes and eosinophil infiltration.
Prevention
Small bag ciliate prevention
The disease is transmitted by mouth, so it should emphasize the food hygiene and personal hygiene, strengthen the management of human and pig manure, avoid the contamination of food and water by pig manure, actively treat sick pigs, etc. The colonic ciliate cysts are more resistant to the external environment. It can survive for 2 weeks at room temperature, can survive for 2 to 3 months in humid environment, and can survive for 4 hours in 10% formaldehyde solution. Therefore, harmless treatment of patients or sick pig feces is particularly important to control the epidemic.
Complication
Small bag ciliate complications Complications peritonitis appendicitis
Even with appendicitis, intestinal perforation, peritonitis.
Symptom
Symptoms of small bag ciliate disease Common symptoms dysentery bloating, urgency, heavy diarrhea, paroxysmal abdominal pain, abdominal pain, dehydration, nausea, lack of appetite, loss of appetite
Most of the colonic ciliates are asymptomatic after infection. The incidence is less than 1/5. The clinical manifestations can be divided into acute and chronic.
1. Acute type: rapid onset, diarrhea is obvious, several times a day or more than ten times, severe cases can reach dozens of times, stool has mucus or pus and blood, but there is no scent of amoebic dysentery, common abdominal pain And accompanied by urgency and weight, umbilical or double lower abdomen has tenderness, patients with irregular fever, nausea and vomiting, fatigue and loss of appetite, severe patients can lead to dehydration, malnutrition and weight loss, and even lead to intestinal perforation, this type of disease is shorter , often fail to heal.
2. Chronic type: Insidious onset, with recurrent diarrhea as the main manifestation, the course of disease can last for several months to several years, and it is a periodic episode, often caused by fatigue, cold, drinking or eating fatty food, stool daily Several times, mostly paste or watery, mucus but pus blood is rare, a small number of patients showed alternating diarrhea and constipation, patients with abdominal distension, paroxysmal abdominal pain, active bowel sounds, double lower abdominal tenderness, etc., long course Those may have weight loss, anemia, weight loss, irritability, insomnia, etc.
Examine
Inspection of pouch ciliates
Blood picture
Most patients have normal blood, and patients with acute phase have a mild to moderate increase in white blood cell counts in patients with bacterial infection. Chronic patients may have varying degrees of red blood cell count and hemoglobin reduction.
2. Pathogen examination
Finding colonic pouch ciliates in diarrhea is an important basis for diagnosis. Generally, smear should be directly taken from the patient's fresh feces. The trophozoites can still remain active within 6 hours after the feces are discharged. If the activity is too long, the activity disappears and the observation is due to the colonic pouch. In the human intestine, cysts are rarely formed, so trophozoites should be found in the feces, but cysts may also be found in the feces of a small number of constipation patients. The worms in the feces are often intermittent, and should be repeatedly checked and examined. Attention should be paid to the direct observation of the mucus part of the saline smear. If necessary, it can be stained with iron hematoxylin. The colonic ciliate should be distinguished from the amoeba trophozoite, the animal ciliate and other free living ciliates. The identification feature is that the worm is large, elliptical, and has a longitudinally split cell mouth and nucleus. If repeated fecal examinations are still not found, the sigmoidoscopy can be used to scrape the material from the edge of the intestinal mucosal ulcer or take pathological examination for pathological examination. Trophozoites are often found.
Diagnosis
Diagnosis and identification of small bag ciliate
The cause of acute and chronic diarrhea is unknown. If the treatment is not effective according to bacterial dysentery, the possibility of protozoal diarrhea should be considered. If the patient has close contact with the pig, the patient should be highly alert to the presence of the disease. The stool or intestinal mucosa biopsy reveals the worm. The trophozoites or cysts can be diagnosed. The colonic pouch caterpillars can be grown in various amoebic mediums. If necessary, fresh feces can be used for culture to help diagnose.
The disease must be differentiated from amoebic dysentery, bacterial dysentery, piriformis, non-specific ulcerative colitis, intestinal tuberculosis and other diseases.
