Hookworm Infection in Stomach: A Case Report Found by Physical Examination

Background Hookworm is one of the most parasitic diseases the It is . The main manifestations of hookworm are gastrointestinal and It is caused by the parasites of Ancylostoma duodenale Dubini and (or) Necator americanus Stiles. The larvae can invade human capillaries through the skin or mucous membranes, enter the bloodstream, reach the lungs through the right heart, destroy the capillaries of the lungs, enter the alveoli, travel along the bronchi to the pharynx, enter the digestive tract and reach the small intestine after swallowing, and develop into adults in the upper part of the small intestine Attached to the intestinal mucosa [2] . Methods

tract and reach the small intestine after swallowing, and develop into adults in the upper part of the small intestine Attached to the intestinal mucosa [2] .

Methods
We described one case of a businesswomen who sufferd from persistent symptoms of anemia, weight loss, and fatigue for years. Anemia was not signi cantly improved after routine antianemia treatment. In order to further evaluate the cause of anemia, a gastroscopy was performed, and the microscope showed a single hookworm in the lower stomach. Diagnosis was con rmed by the successful funding of Hookworm eggs in the lining of excrement.

Conclusions
Hookworm is a human parasite transmitted through the faecal-oral route which reside the duodenal bulb normally [3] . Adult worms are not usually seen in the stomach. There are only few cases reporting hookworm infestation of the stomach. In this case report we present an endoscopic demonstration of hookworm infestation in the stomach found by physical examination of a woman who presented with chronic anaemia.
For anaemia patients, especially chronic anaemia patients and those suspected of hookworm disease, gastroscopy should pay attention to the observation of duodenal globules and fecal search for eggs, which are conducive to the early diagnosis of hookworm disease.

Case Presentation
A 35-year-old young woman came to our hospital for physical examination due to fatigue and weight loss. and fatigue. Through bone marrow examination two years ago, she was diagnosed with iron de ciency anemia. After symptomatic treatment with iron, the symptoms of anemia did not improve signi cantly. This time she was admitted to the hospital due to fatigue and worsening.
The levels of folate, vitamin B12, and iron metabolism were tracked, and non abnormal changes were found, exclude patients from anemia caused by insu cient hematopoietic materials. Whether it is possible for the patient to have anemia due to gynecological diseases, ask the patient's menstrual history, the patient's regular menstrual period, moderate menstrual volume, perfect gynecological color Doppler ultrasound and HPV examination, no abnormalities are found. Exclude anemia caused by gynecology, considering anemia caused by digestive system diseases or tumors. Non abnormal changes in tumor markers and perfect lung CT, full-abdominal CT and other imaging examinations. Full-abdominal CT suggests that the suspicious wall of the gastric antrum is slightly thicker. In order to further evaluate the cause of anemia, a gastroscopy was performed. Painless gastroscopy suggests that the gastric parasites, chronic gastritis-non-atrophic. It can be seen under the microscope that a single parasite in the gastric antrum bites the gastric mucosa. Use biopsy forceps to remove the parasite completely. After pulling it, the parasite size is 15×1mm, and the appearance is similar to hookworm. Additional colonoscopy did not nd other parasites in the intestinal wall Signs of infection.

Methods And Results
The patient's feces and the removed parasites were sent to the Parasitology Department for further clari cation, and the results suggested that the parasite was clearly diagnosed as hookworms, and hookworm eggs were found in the patient's feces (Figures 2). The patient was de nitely diagnosed with gastric hookworm disease. To be treated with antiparasitic drugs (albendazole) and iron supplementation.

OUTCOME AND FOLLOW-UP
After removing the parasites for 1 week, the patient's hemoglobin improved HBG 103g/L . After 6 months, the HBG was in the normal range HGB 123g/L , and the endoscopy showed that there were no parasites in the stomach, only super cial gastritis.

Discussion
Hookworm infections are common in the tropics and subtropics. The prevalence of hookworm infection is highest in sub-Saharan Africa, followed by Asia, Latin America, and the Caribbean. It is estimated that over 800 million people are infected with hookworms worldwide [3] .The prevalence of hookworm infection in China is 6.12%, with neraly 39.3 million infected people [1] .
A diagnosis of hookworm infection includes a history of skin exposure to potentially contaminated soil, clinical manifestations, and stool examination, which is the primary established tool. The patient lives in the river basin, prefer to eat raw sh and seafood, had a history of travel to the southern of china and barefoot walking. Clinical manifestations include Chronic nutritional impairment, pulmonary infection and gastritis. The result of stool egg testing was positive. The nal diagnosis of hookworm infection was established.
The hookworm life cycle begins with passage of eggs from an adult host into the stool. Hookworm eggs hatch in the soil to release rhabditiform larvae that mature into infective lariform larvae. Infection is transmitted by larval penetration into human skin; as few as three larvae are su cient to produce infection [4] . From the skin, larvae migrate into the blood vessels and are carried to the lungs.
Approximately 8 to 21 days following infection, larvae penetrate into the pulmonary alveoli, ascend the bronchial tree to the pharynx, and are swallowed. In addition to percutaneous larval penetration (the principal mode of transmission), some species of hookworm infection may also be transmitted by the oral route.
The hookworm are not usually seen in the stomach. So far only a few reports of hookworm infestation of the stomach are available [5] . In this case, we didn't seen any parasite in duodenum or other intestinal tract but single one in stomach. The proposed mechanism by which the worm parasite in the stomach body might be relationed to the chronic gastritis and low immunity. Chronic gastritis results in gastric acid secretion change, and Long-term anemia and long medical history leads to low immunity. Provides a condition for hookworm to parasitism in the stomach.
Anemia is the main symptom of hookworm disease. Studies have shown that the mechanisms by which hookworms cause anemia are manifold. Hookworms attach to the mucosa of the gastrointestinal tract through biting, and the blood vessels at the attachment site will leak and lose blood due to the biting of hookworms. In addition, hookworms can cause the secretion of anticoagulants, leading to blood loss. In addition, it was found that hookworm infection can cause iron loss. In the case of moderate to severe hookworm infection, when the blood loss exceeds the host's intake and iron and protein reserves, chronic IDA will occur. This patient has multiple cysts in liver and kidney in CT, round saccate shadows were seen in the splenic hilum with marginal calci cation. Multiple round low-density shadows were seen locally in the right lung, subpleural nodules were in the upper lobe of both lungs. Whether the above changes are related to hookworm infection remains to be further observed.

Conclusion
Hookworms have been infecting humans for a long time, spreading across the world, and seriously endangering human health after infection. Due to their lack of speci c symptoms and signs, they are easily missed and misdiagnosed. This case may indicate that the patient is clinically found to have symptoms of anemia or gastrointestinal bleeding, but it is di cult to nd the cause of the cause, consider whether there is the possibility of hookworm infection, and perform endoscopy and fecal worm egg detection as soon as possible. Early diagnosis and treatment will reduce The continuous damage of hookworms to the human body.  Figure 1 Hookworm adsorption on the stomach