Ancylostomiasis is an intestinal parasitic disease caused by hookworm parasitic in human small intestine. In China, hookworms parasitic on human bodies are mainly hookworms in duodenum and hookworms in the United States.
Hookworm infection is almost all over the world. In China, except for a few dry and cold areas, hookworms are infected or prevalent in other provinces, especially Hainan, Sichuan, Yunnan, Guangdong, Guangxi, Fujian, Zhejiang, Jiangsu, Hunan and Anhui.
People are often infected if their feet or hands come into direct contact with soil or crops containing hookworm larvae when they are engaged in labor activities such as growing vegetables and farming in the field. It can also be infected by eating raw unclean vegetables and fruits containing hookworm larvae.
The larvae of hookworm invade the skin, enter the human body, migrate in the human body, and finally reach the small intestine to develop into adults. After laying eggs, adults are excreted with feces and develop into infected larvae in soil environment. Therefore, hookworm disease is an important soil-borne nematode disease.
The common clinical symptoms of hookworm disease are anemia, malnutrition and digestive tract dysfunction, which can cause cardiac insufficiency and children's growth and development disorders in severe cases. Infection in pregnant women can lead to miscarriage, premature delivery or stillbirth. Infants infected with hookworm disease often have acute bloody diarrhea, tarry stool, loss of appetite and high mortality.
When hookworms invade the human body and migrate in the body, they may have different symptoms. For example, after hookworm larvae invade the skin, patients may feel burning, pricking or itching in local skin. Followed by red punctate papules or blisters, leading to hookworm dermatitis, more common between fingers and toes. After the larva migrates to the alveoli, the patient may have itchy throat, cough and bloodshot sputum, and severely infected people may have severe dry cough, massive hemoptysis in the lungs and asthma-like attacks. Adults parasitize the small intestine, constantly changing the parts on the wall of the small intestine to suck blood, and the wound constantly bleeds, resulting in anemia. Patients often have upper abdominal pain and discomfort, loss of appetite and other symptoms. Because of poor appetite and digestive function, it affects the absorption of iron, aggravates anemia and even causes gastrointestinal bleeding. A few hookworm patients like to eat "heterophiles" such as raw rice, soil and charcoal.
If hookworm eggs or hookworm larvae are found in feces, it can be diagnosed as hookworm infection. Although some people have been infected with hookworm and hookworm eggs have been found in feces, there is no obvious clinical symptom, which is called hookworm infection.
The treatment of hookworm disease can be treated by expelling intestinal adults and killing early larvae moving in tissues. Commonly used anthelmintics include albendazole, mebendazole and pyrimidine. In recent years, triphenyldiamidine, a new drug synthesized in China, has a good effect in repelling hookworms in the United States. In addition, iron agents such as ferrous sulfate tablets or iron gluconate can be taken orally, which is helpful to improve anemia and heart function. Patients with severe anemia can receive blood transfusion.
To reduce and control hookworm disease, we must adhere to measures such as insect repellent treatment, strengthening feces management and ensuring the cleanliness and hygiene of drinking water. In addition, widely publicize and popularize the knowledge of hookworm disease prevention and control, develop good hygiene habits, do not drink raw water, and wash raw fruits and vegetables repeatedly, especially to change the bad habit of working barefoot and enhance self-care awareness.
echinococcosis
Echinococcosis is a parasitic disease of human and animals caused by echinococcosis. There are two kinds of cystic echinococcosis and alveolar echinococcosis in China, which are caused by the larvae of Echinococcus granulosus and Echinococcus multilocularis parasitizing human tissues and organs. Cystic echinococcosis is distributed all over the world, especially in countries and regions with developed animal husbandry. The high incidence and epidemic areas of echinococcosis in China are mainly concentrated in alpine meadow areas, pastoral areas with cold climate, drought and little rain, and semi-agricultural and semi-pastoral areas, especially in Xinjiang, Qinghai, Gansu, Ningxia, Tibet, Inner Mongolia, Shaanxi, Hebei, Shanxi and northern Sichuan.
Wild animals such as dogs and foxes are the main sources of infection. Dogs are infected by eating the internal organs of sick animals. The eggs discharged by sick dogs pollute the natural environment such as pastures and water sources and livestock products such as wool. People get infected by touching domestic dogs or eating water, vegetables or other foods contaminated with eggs. In addition, many people will get infected by mistake when they come into contact with eggs during grazing, shearing, milking and fur processing. Cattle, sheep and other livestock are infected by eating contaminated pasture, feed or drinking contaminated water.
Echinococcus can be parasitic in any part of the human body and involve multiple organs at the same time. Liver swelling and pain can be seen in the liver; Stimulating symptoms such as shortness of breath and chest pain can be seen in the lungs; In the brain, a series of symptoms that can cause increased intracranial pressure; In bones, it will destroy bones and easily cause fractures. The disease is mainly chronic consumption, which often makes patients lose their ability to work.
Echinococcus is mainly parasitic in human liver, but it can affect organs such as lung and brain through infiltration and diffusion, blood diffusion and lymphatic metastasis. It is like a malignant tumor, which has serious damage to the tissue. Therefore, alveolar echinococcosis is called "parasitic tumor" and "second cancer".
Echinococcosis can be diagnosed clinically by serological detection, X-ray, B-ultrasound, CT and other means. The ultrasonic image of hydatid cyst is very characteristic, so the coincidence rate of B-ultrasound diagnosis can reach over 98%.
Surgery is the first choice for treatment, and echinococcosis parasitic on human organs is mainly treated by internal capsule puncture and complete internal capsule removal. Albendazole, praziquantel, mebendazole and other drugs have certain effects on early echinococcosis. Clinical trials of albendazole emulsion developed in recent years have proved that it can replace surgical treatment to some extent.
Echinococcosis is a parasitic disease with local and natural foci, and all localities should pay attention to health publicity and education. High-risk groups, herders and hunters engaged in slaughtering industry should strengthen personal protection in production and life, and do not drink raw water or eat lettuce. Children should avoid close contact with dogs and wash water before meals. Kill wild dogs, limit the number of dogs raised, prohibit feeding dogs and livestock with animal organs containing worms, and strengthen the deworming of domestic dogs. The feces of people and dogs after deworming should be treated harmlessly. Strict implementation of meat food hygiene inspection system and animal quarantine system.
Clonorchisis
Clonorchis sinensis, also known as liver fluke disease, is a zoonotic parasitic disease, which is mainly caused by Clonorchis sinensis parasitic in human hepatobiliary duct. It is one of the most serious food-borne parasitic diseases in China at present. At present, liver fluke disease is popular in Guangdong, Guangxi, Hongkong, Taiwan Province and Northeast China in the Pearl River Delta. The Yangtze River basin, Huanghuai basin and some hilly areas are mild and moderate.
Clonorchis sinensis adults are mainly parasitic in the hepatobiliary ducts of mammals such as humans, dogs, cats and pigs. Eggs excreted by adults enter the small intestine through bile, and then are excreted with feces. After entering the water, the eggs were swallowed by the first intermediate host freshwater snails, and developed into cercaria to escape in the snails. The cercaria meets the second intermediate host freshwater fish in the water and drills into the fish to develop into cysticercosis. People get infected by eating raw or half-eaten fish and shrimp containing live metacercariae. Cysticercosis enters the human duodenum through the mouth, then moves to the bile duct and develops into an adult.
In epidemic areas, people eat fish and shrimp raw or half-eaten, which is the main mode of infection. If you eat sashimi and fish porridge, process the fish half-cooked, or eat small fish, you can get infected by eating live metacercariae. In addition, using the same chopping block to treat raw and cooked food or drinking raw water may also infect this disease. Build toilets near fish ponds in epidemic areas, and put fresh manure directly into fish ponds as feed. The eggs of Clonorchis sinensis can enter the water to infect fish after the development of intermediate host Oncomelania hupensis. Feeding pigs with fish washing water and cats and dogs with raw fish and shrimp will lead to infection of these animals. Animal manure entering the water pollutes fish ponds, which will also cause the spread of liver fluke disease.
Acute liver fluke disease can be caused by ingesting a large amount of metacercariae of Clonorchis sinensis at one time, and the incubation period is generally about 30 days. Patients with acute diseases have an acute onset. The initial symptoms are epigastric pain and diarrhea. This kind of pain is similar to acute cholecystitis and may be accompanied by biliary obstruction. After 3-4 days, fever occurs, and the body temperature can reach 39.7℃, and then hepatomegaly can occur, mainly in the left lobe. Examination showed tenderness in liver area, pain under sword, jaundice, urticaria and eosinophilia in peripheral blood. Chronic patients usually have occult onset, ranging from abdominal pain, diarrhea, malnutrition, fatigue, dull pain in liver area, hepatomegaly and other clinical symptoms to cholecystitis, cholangitis, gallstones and bile duct obstruction. Children may also show developmental disorders, which can lead to dwarfism in severe cases. It was found that Clonorchis sinensis infection was also related to the occurrence of bile duct epithelial carcinoma and mucinous carcinoma.
Liver fluke disease's diagnosis is mainly based on finding the eggs of Clonorchis sinensis in human feces or bile. At present, the most commonly used therapeutic drugs are praziquantel and albendazole, which have good curative effects.
Reducing the source of infection and actively treating patients and carriers are important measures to prevent and treat this disease. In epidemic areas, it is necessary to carry out general surveys and treatment frequently, and find patients and sick animals in time and treat them. The simplest and most effective way to prevent this disease is to carry out health education, to prevent the disease from entering the mouth, and not to eat raw or undercooked fish and shrimp. In addition, strengthening the management of feces, advocating pigs and other domestic animals, not feeding animals with raw fish and shrimp, preventing eggs from entering the water with feces, combining patriotic health campaign with rodent control and snail control in fish ponds are all effective methods to control the spread of the disease.
kala-azar
Kala-azar, also known as visceral leishmaniasis, is a disease caused by Leishmania parasitizing macrophages in liver, spleen, bone marrow, lymph nodes and other visceral tissues. Kala-azar is prevalent or distributed in 5/kloc-0 countries around the world. Kala-azar was once prevalent in 16 provinces (cities, districts) in China, but it was basically eliminated in most areas after large-scale effective prevention and control in 1950' s. At present, only six provinces (districts) such as Xinjiang, Gansu, Sichuan, Shaanxi, Shanxi and Inner Mongolia still have new cases.
Sandfly is the vector of kala-azar. When a sandfly bites an animal suffering from kala-azar, Leishmania flagellum in blood and skin can enter the stomach of the sandfly and reproduce into a pre-flagellum. When the sandfly sucks blood again, the pre-flagella will enter the macrophages of human or animals and become flagellates. Macrophages containing Leishmania enter the spleen, liver, bone marrow and lymph nodes through lymph or blood flow. The proliferation of protozoa causes a large number of destruction and extreme proliferation of macrophages, leading to a series of pathological changes in the above organs.
People with kala-azar will also be infected if their blood is lost to healthy people by mistake. Congenital kala-azar is passed from mother to baby. Dogs can also suffer from kala-azar In western China and the vast mountainous areas of the Loess Plateau, sick dogs are closely related to the spread of human kala-azar.
The main symptom of kala-azar is long-term irregular fever, followed by splenomegaly, accompanied by cough and diarrhea. Fear and insomnia are common symptoms in the early stage of kala-azar. In addition to fever, diarrhea and other symptoms, infants can also cry at night and be agitated. Early symptoms of female patients usually include menorrhagia or amenorrhea. In the late stage of the disease, most patients are emaciation, anemia, leukopenia, listlessness, sparse and dull hair, dry skin, pale face and black pigmentation. The abdomen is often prominent due to hepatosplenomegaly, and the limbs appear thinner. Sometimes lesions such as papules or nodules can appear on the skin, and children's development is blocked after illness.
The etiological diagnosis of this disease is to perform iliac puncture or lymph node puncture, extract the patient's bone marrow or lymph tissue, and check whether there is protozoa under the microscope after smear staining; Or culture the extracted bone marrow and lymphoid tissue in NNN medium, and examine the flagella under the microscope. The first choice for the treatment of kala-azar is sodium antimonate pentavalent gluconate.
The main measures to prevent the occurrence of kala-azar are that sick dogs should be killed at any time after being found, cremated or buried immediately, and the main sources of infection should be eliminated. Find out the patients who should be cured and reduce the spread. Advocate the use of mosquito nets, screen doors and screens to prevent sandflies from invading. Field workers who enter desert epidemic areas can apply repellent to exposed parts of their bodies at night to reduce the bite of sandflies.