OVERVIEW
Ascaris lumbricoides is the most common intestinal parasitic disease. Ascaris lumbricoides parasitizes the human small intestine, and most patients have no obvious symptoms, while some patients may have different degrees of clinical manifestations. In addition to intestinal roundworm symptoms, it can also cause biliary ascariasis, ascaris intestinal obstruction and other serious complications.
Etiology
The source of infection is patients with ascariasis and infected people. A large number of eggs are discharged with the patient’s feces, contaminate vegetables and soil, and develop into mature eggs after about 2 weeks under suitable temperature and humidity. Most of the mature eggs are killed by gastric acid when they pass through the mouth to the stomach, and a few of them enter the small intestine to hatch and develop into larvae.
Symptoms
Intestinal ascariasis often causes recurrent episodes of abdominal pain in the upper abdomen or around the umbilicus. Due to the mechanical irritation of the worms and their secretion of poisons and metabolites can cause gastrointestinal dysfunction and heterogeneous protein reactions, such as nausea, nausea, vomiting, diarrhea and urticaria. Children with severe infection can cause malnutrition, mental disturbance, insomnia, teeth grinding, night terrors.
Intestinal roundworms are generally in a quiet state, but after various stimuli (such as high fever, indigestion, improper deworming, etc.), it is easy to make the roundworms riot and drill, which can cause serious complications, and the common ones are:
1. Biliary Ascariasis
Biliary ascariasis is caused by roundworms drilling into the biliary tract, manifesting as sudden paroxysmal colic or drilling pain under the raphe, radiating to the back and the right shoulder, which is hard to bear and extremely disturbing. It is often accompanied by nausea and vomiting. The abdominal wall is soft only mildly spasmodic during pain episodes, and there is obvious limited pressure pain under the raphe. When the roundworms entering the biliary tract retreat to the small intestine, the symptoms suddenly disappear. If Ascaris lumbricoides enters the gallbladder duct or intrahepatic bile duct, it can cause acute pyogenic cholecystitis, cholangitis or acute hemorrhagic necrotizing pancreatitis as a result of secondary bacterial infections; and it can produce bacterial liver abscess when it penetrates into the intrahepatic bile duct. When Ascaris lumbricoides remains or Ascaris lumbricoides eggs stay in the bile duct or gallbladder for a long time, it can be the core of the gallstones, which can be formed gradually.
2.Ascaris lumbricoides intestinal obstruction
Mostly seen in children. Due to the large number of worms, twisted into a mass to block the intestinal lumen, causing partial intestinal obstruction. The patient has paroxysmal abdominal pain, nausea, vomiting, soft abdominal wall, can be found in the size of coarse hemp rope-like cord-like lumps. If not treated in time, it can develop into complete intestinal obstruction.
3.Other
After typhoid fever or a few patients with gastric or duodenal ulcer disease are infected with roundworms, the roundworms can perforate the gastrointestinal wall of the lesion and cause perforation, resulting in diffuse peritonitis. Ascaris lumbricoides can be discharged from the nostrils and mouth when traveling upward and retrograde, or drilling into the eustachian tube and causing perforation of the eardrum and discharge of worms from the external auditory canal. Occasionally roundworms may reach the larynx or trachea and cause asphyxia.
Examination
Direct fecal smear examination.
Diagnosis
Based on the epidemiologic history, the presence of malaise, coughing or asthma-like episodes, inflammation of the lungs, eosinophilia, anorexia, abdominal pain, and weight loss should alert to the possibility of ascariasis. The diagnosis of ascariasis can be clarified by finding roundworm eggs on fecal examination, shadows of roundworms on barium gastrointestinal fluoroscopy, or a history of fecal expulsion or vomiting of roundworms. In the presence of colic, cholangitis, pancreatitis should be considered the possibility of Ascaris ectasia, and diagnosed by ultrasound, retrograde cholangiopancreatography. Ascaris lumbricoides intestinal obstruction is more common in children, and a striated mass in the abdomen, combined with radiologic examination, helps to make the diagnosis.
Treatment
1.Deworming treatment
Benzimidazoles are broad-spectrum anthelmintics that can kill roundworms and hookworms. The insecticidal mechanism is that the drug selectively and irreversibly inhibits the glucose uptake of the worms, which depletes the endogenous glycogen of the worms and inhibits the enzyme fenugreek acid reductase, hindering the production of adenosine triphosphate, which makes the worms unable to survive and reproduce, and ultimately die. Commonly used drugs are:
(1) Albendazole tablets, trade name Schick’s Intestinal Worm Clear, a new broad-spectrum anthelmintic, swallowed at once. The efficacy is over 90%. It is relatively safe and effective in killing adult worms and eggs.
(2) Mebendazole, once in the morning and once in the evening, for 3 days; if not exhausted, a second course of treatment can be used after three weeks. This drug is more effective in driving roundworms, side effects are rare, when a large number of infections are driven with this drug, there may be abdominal pain, diarrhea, but it is mild.
(3) Levamisole, once taken, this drug is not as effective as mebendazole, but better than piperazine citrate, side effects are mild, occasionally nausea, vomiting, loss of appetite, etc., a small number of patients with mild impairment of liver function after taking the drug. Early pregnancy, liver, kidney disease should be used with caution.
(4) Thiabendazole, once in the morning and once in the evening, for 3 days, this drug has been replaced by mebendazole.
(5) Thiamphenicol, known as anthelmintic and anthelmintic, is a broad-spectrum anthelmintic, which can make the muscle of roundworm contract violently and cause spasmodic paralysis. It is taken once at night. Side effects include headache, dizziness, vomiting, etc. It should be temporarily given to pregnant women, acute hepatitis, nephritis, severe heart disease and febrile patients.
(6) Ascaris lumbricoides, also known as piperazine citrate, taken at bedtime for 2 days, plus laxatives for constipation. Side effects are mild, with occasional dizziness, vomiting and headache. This drug has been gradually used less.
2. Treatment of complications
(1) biliary ascariasis ① atropine, chlorpromazine or dulcolax to antispasmodic and analgesic; ② deworming treatment after the relief of abdominal pain; ③ timely use of antibiotics to control biliary tract infection.
(2) Ascaris lumbricoides intestinal obstruction, incomplete intestinal obstruction, first with internal medicine treatment, including sedation, antispasmodic, analgesic and gastrointestinal decompression, to be relieved after the abdominal pain and then deworming. When complete obstruction occurs, it should be treated surgically.
Prevention
Educate children to develop good hygiene habits, do not eat raw fruits and vegetables should be washed, wash hands before and after meals, often cut nails, do not suck fingers.
Prognosis
Ascaris lumbricoides parasites in the body usually die within 1 to 2 years, that is to say, if infected with ascariasis, without any treatment, as long as to do not repeat the infection, the worm can be discharged by itself in 1 to 2 years. On the other hand, although roundworm disease has been effectively treated, if you do not pay attention to hygiene, so that the eggs re-entered the human body, two months later in the intestinal tract will develop into adult worms.