Overview
Flagellosis is a common intestinal parasitic disease caused by the hairy whipworm parasitizing the human cecum, appendix and ascending colon, widely distributed, especially in tropical and subtropical areas with the highest incidence, and it is common in China, especially in rural areas.
Patients are mainly children, severe infection can affect the growth and development of children, light and moderate infection can be asymptomatic; severe infection with diarrhea, blood in the stool, acute and severe, rectal prolapse, anemia and malnutrition.
Causes
Whipworm disease is caused by infection with whipworms.
People are infected by swallowing food containing eggs that have been incubated in soil for 2 to 3 weeks. The eggs hatch in the small intestine to form larvae, which migrate to the large intestine and extend their heads into the intestinal wall. Each larva is about 11 cm long, and mature females lay about 5,000 eggs per day, which are excreted in the feces.
Morphology
Adult larvae are dark red when alive, grayish white when dead, and resemble a horsewhip in appearance, with an elongated anterior end, accounting for about 3/5 of the body length, and a distinctly thicker posterior end. The whipworm’s mouth is extremely small, with two half-moon shaped labellum. Between the two labial valves there is a sharp knife-like mouth spear, which can be extended from the oral cavity when active. The pharyngeal tube is elongated, the anterior section is muscular and the posterior section is glandular. The pharyngeal tube is surrounded by rods composed of rod cells arranged in a series of spheres, and the secretions of the rod cells may have enzymes that digest host tissues and are antigenic. Female worms are 35 to 50 mm long, with a bluntly rounded caudal end and a pubic valve located on the ventral surface in front of the thick part of the body. Males are 30 to 45 mm long, with the caudal end curled in a ring toward the ventral surface, with one symphysial spine, which may protrude from the sheath, and small spines on the surface of the sheath. The reproductive system of adults of both sexes is monotubular.
Flagellate eggs are fusiform (girdle-shaped), about 50-54 × 22-23 µ m in size, yellowish brown, with thick shells and a transparent opercular blug containing an oocyte at each end. When the eggs are expelled from the body, the cells in the egg shell have not yet divided.
Life history
In the small intestine, the activity of the larvae inside the egg increases, and the action of secreted enzymes, the larvae escape from the cover plug at one end of the eggshell. And mostly invade the local intestinal mucosa from the crypts of intestinal glands to take nutrients and develop. After about 10 days, the larvae return to the intestinal lumen and migrate to the cecum, where their slender anterior end burrows into the intestinal mucosa to the submucosal tissues, while the posterior end is exposed in the intestinal lumen to parasitize and develop into adult worms. It takes one to three months from the time of accidental ingestion of infected eggs to the time when the adult worms mature and lay eggs. Whipworms can generally survive in the human body for 3 to 5 years.
Pathogenicity
Adult whipworm inserts into the intestinal mucosa and even the submucosa with its elongated anterior segment to take nutrients from the tissues and blood, together with the stimulating effect of secretion, the intestinal mucosal tissues show mild inflammation or punctate hemorrhage, and epithelial cells can also be seen to be degenerated and necrotic. In a few patients, granuloma is formed due to inflammation of the intestinal wall, cell proliferation and thickening of the intestinal wall. Some scholars observed with 51Cr, measured that each whipworm makes the host lose about 0.005ml of blood per day, so the average patient does not produce anemia symptoms. When the infection is severe (i.e., the number of parasites exceeds 800) chronic blood loss caused by whipworms can lead to the development of iron-deficiency anemia. In addition, immunological studies have shown that human infections with whipworms can produce a certain degree of immunity. Animal studies have shown that the rods of whipworms are a major source of functional antigens.
Symptoms
Mild and moderate infections are usually asymptomatic, although clinically common. Occasionally, right lower abdominal pain, nausea, vomiting, and low-grade fever are present. Severe infections are most common in children and have the following manifestations:
1. Digestive system
Different degrees of congestion, edema, diffuse chronic bleeding spots, and ulcer formation in the colon. Patients present with diarrhea, pus and blood stools, urgency, and prolapse. Some patients present with symptoms of chronic appendicitis, and abdominal palpation is often accompanied by obvious pressure pain in the right lower abdomen.
2. Blood system
Routine blood tests show increased eosinophils and iron deficiency anemia. Severe anemia leads to heart enlargement.
3. Nervous system
Frequent dizziness and lightheadedness. Very few may have symptoms of meningitis.
Examination
1. Blood tests
Pay attention to eosinophil count, microcytic hypochromic anemia.
2. Stool routine
Look for eggs, saturated saline floatation method to find eggs to confirm the diagnosis.
3. Egg count
4. Rectal microscopy
Or on the prolapsed rectum, the diagnosis can also be confirmed by the detection of adult whipworms.
5. Quantitative plate-glycerol glass counting method (Garten’s modified method)
The degree of infection can be determined.
6. Sigmoidoscopy or fiberoptic colonoscopy
On examination, the worms can be seen adhering to the intestinal mucosa, and mucus can be seen next to the worms. The mucosa is mildly congested and bleeds easily. Colonoscopy can also be used as a means of differential diagnosis to exclude other intestinal diseases.
7. X-ray barium enema examination
Using gas-barium double contrast method, a light-permeable worm coated with barium can be found.
8. Other examinations
(1) Saline direct smear method.
(2) Saturated saline floatation method.
(3) Water-washed natural precipitation method.
Diagnosis
Detection of whipworm eggs in the feces is the basis for diagnosis.
Treatment
No treatment is needed for mild and moderate infections, severe infections should be given high protein and easy to digest diet, iron should be given to correct anemia, combined with amoebic dysentery with metronidazole anti-amoebic treatment, combined with bacillary dysentery should be treated with antibiotics.
1.Drug deworming treatment
(1) Albendazole capsules or tablets taken at once for 2 days, the negative rate of worm eggs 43.2%～52.7%, side effects are mild, the course of treatment for severe infections is 5～7 days, there are no obvious side effects, there are occasional dizziness, nausea, abdominal pain, vomiting worms, or transient transaminase elevation and other minor reactions, which can be relieved on their own.
(2) Mebendazole 3 days in a row, the cure rate of 60% to 80%, a significant reduction in the number of untreated eggs, children’s dose is reduced by half, severe infections can be treated for 6 days or repeat a course of treatment, the patient is well tolerated, only minor gastrointestinal reactions, pregnant women are contraindicated for children under the age of 12 years with caution. Mebendazole, levamisole (compound mebendazole) tablets efficacy 80% to 83.8%.
(3) Oxytetracycline Oral, 2-day therapy, the cure rate is 57%. Or taken for 5 days, the cure rate is 100%. Side effects are mild and transient, and can be relieved on their own.
(4) Compound thiamphenicol Each tablet contains thiamphenicol and oxytetracycline, taken at once, delivered for 2 days, the negative rate of worm eggs reaches 93.8%, and has good effect on roundworms, hookworms, pinworms.
(5) Obendazole, taken at once, 4 weeks after the treatment of eggs qualitative review results, the negative rate of 70.4%, 70.4% and 53.3%, respectively.
(6) Flubendazole, taken for 2 days, the cure rate was 86%.
(7) Intestinal worm clean The main ingredient is albendazole, take it at once, the negative rate of worm eggs is 71.7%, the side effects of this drug are few, occasionally headache, gastrointestinal discomfort, usually disappear in 48 hours, children under 1 year old and pregnant women should not take.
(8) Traditional Chinese medicine: Betel nut decoction, take magnesium sulfate one night before taking the medicine, and then take betel nut decoction in several times in the next morning, and those who don’t have diarrhea for 3 hours after taking the medicine should take magnesium sulfate once more.
(9) Oxygen deworming 2 hours after breakfast, inject 500ml of oxygen through the anus slowly (30 minutes), 45 minutes later, take magnesium sulfate orally for 1 time, inject 750ml and 1000ml of oxygen on the 2nd and 3rd day as above, gently massage the patient’s right lower abdomen after injecting the oxygen and let the patient lie on his/her back for an hour, this kind of therapy does not have any side effect.
2. Fiber colonoscopy treatment
When the infection is serious, the use of medication often can not be completely cured, available endoscopic forceps method, under direct vision with a biopsy forceps gently clamp the worm, from the intestinal mucosa pulled out.