metacercariae

Oral infection, eating raw freshwater fish, shrimp, etc. containing metacercariae

Hepatobiliary duct

The final hosts are humans and mammals, the first intermediate host is freshwater snails (bean snails), and the second intermediate host is freshwater fish. Cats are an important insect host.

Damage to the liver, causing hypersensitivity around the bile ducts, biliary cirrhosis

Complications and complications are many: cholecystitis, cholangitis, gallstones, hepatobiliary obstruction

Smear method, egg collection method, duodenal drainage bile test

praziquantel, albendazole

Strengthening fecal management, killing snails, and preventing ingestion of live metacercariae are the keys to preventing and treating this disease.

metacercariae

Oral infection

upper small intestine

The intermediate host is the flat snail, and the final hosts are humans and pigs, with wild rice, water chestnuts, water chestnuts and other aquatic organisms as transmission media.

Mechanical damage (can cause the adsorbed mucosa to necrosis and fall off), hypersensitivity reaction caused by insect metabolites being absorbed by the host In case of intestinal obstruction, adults of Fasciata ginger can occasionally parasitize in the biliary tract. Patients may experience recurring dull pain in the right upper abdomen, accompanied by low-grade fever and abdominal distension.

Check for eggs in feces

praziquantel

metacercariae

Pass through the mouth and migrate through the body (through the intestinal wall → abdominal cavity → through the diaphragm → chest → lungs)

lungs

The first intermediate host is freshwater snail (Sichuan snail), and the second intermediate host is river crab or mantis.

The migration of child worms causes mechanical damage and metabolites cause immunopathological reactions; Hemorrhagic or purulent sinus tracts, serous fibrinous peritonitis, pinprick holes on the liver surface

Pathological processes caused by cysts

acute phase

Chronic phase

Direct smear method: Detection of insect eggs in sputum/feces, biopsy

praziquantel

Do not eat raw or semi-raw freshwater crabs, crickets, and their products, and do not drink raw water.

Cercariae (water containing cercariae is called plague water)

Infection through the skin, migration of the worm into the body

portal-mesenteric venous system

The only intermediate host: snail Definitive host: human, cow, pig

Cercariae: cercarial dermatitis

Childworm: transient vasculitis, capillary embolism, rupture, local cellular infiltration and spotting hemorrhage Mechanical damage, metabolites causing hypersensitivity reactions

Adult: Endophlebitis

Eggs (main pathogenic stage): egg granuloma Formation mechanism: After the eggs deposited in the tissue mature, the soluble egg antigens released by the miracidia in the eggs penetrate into the host tissue through the micropores on the egg shell, and are presented to helper T cells through antigen-presenting cells such as phagocytes. After being stimulated by the same antigen again, the sensitized Th cells produce various lymphokines, attract lymphocytes, eosinophils, neutrophils, plasma cells, and fibroblasts, and gather around the eggs to form worms. Egg granuloma, leading to cirrhosis or intestinal fibrosis. Advantages: It is helpful to isolate the damage caused by the hepatotoxic antigens in the soluble antigens secreted by the eggs to adjacent liver cells, and avoid the occurrence or exacerbation of local or systemic immune diseases. Disadvantages: It can continuously destroy the tissue structure of liver and intestines, which is the main cause of chronic schistosomiasis.

Heberli phenomenon (eosinophilic abscess, plasma cells with deposition of antigen-antibody complexes)

Mainline liver fibrosis

acute schistosomiasis

chronic schistosomiasis

advanced schistosomiasis

Ectopic schistosomiasis

concomitant immunity

Precipitation incubation method, thick smear transparency method, modified Kato method

Water network type, lake type, hill type

praziquantel

Snail eradication, manure management, safe water supply

Artemisinin has a very good killing effect on child worms

Sparganosis

It takes 3-4 hosts to complete the life cycle

Most suitable definitive host: cat Definitive host: dog, feline The first intermediate host: Daphnia Second intermediate host: frog Changing hosts: snakes, birds, pigs

Adult worms inhabit the small intestine of the definitive host It is parasitic in human eyes, subcutaneous on limbs, mouth, maxillofacial area and internal organs.

Ocular schizocephalosis

subcutaneous sparganosis

Oral and maxillofacial sparganosis

Cerebral sparganosis

Visceral sparganosis

Fecal examination for worm eggs to confirm diagnosis, biopsy

Local application of frog meat

Swallowing raw or undercooked frogs, snakes, chicken or pork

Ingestion of water infected with water fleas

Strengthen health education, praziquantel, albendazole Sparganosis is mainly removed by surgery

Cysticerci

People accidentally eat pork containing cysticercosis, accidentally eat gestational worms or eggs

Humans are the only definitive host and can also serve as intermediate hosts. Pigs and wild boars are the main intermediate hosts.

Parasitic in the upper part of human small intestine

Taenia solium causes Taenia solium taeniasis, and the larvae of Taenia solium cause cysticercosis, also known as cysticercosis, which is far more harmful to the human body than the adult worms

Cysticercosis

Ask about the history of eating raw pork and cutlet slices, and conduct fecal examination

Anal swab method, transparent tape method

Autologous infection, autologous infection outside the body, allogeneic infection

Deworming patients

Manage toilets and pig pens well

Strengthen meat inspections

Strengthen health education

Cysticerci

Eating beef containing cysticerci

Human is the only definitive host, upper small intestine

Taenia saginata

Stool test, anal swab method

Taenia solium

Eggs containing hexapod larvae

Accidentally eating insect eggs

Definitive host: dog, wolf, fox Intermediate host, human, cow, sheep, pig

Mainly the liver, mostly in the right lobe, lungs, abdominal cavity, brain...

Only the echinococcal stage can parasitize the human body

Local compression and irritation symptoms

Toxicity and allergic reactions

Complications such as secondary infection

Avoid puncture, CT, MRI, ELISA The diagnosis should be based on the etiological results, that is, surgical removal of echinococcosis

Infectious eggs

Transmitted by mouth, eating contaminated food, water

small intestine

Larvae causes: Ascaris asthma, Ascaris pneumonia (eosinophils or Ascaris larvae can often be found in sputum smear examination at this stage)

Pathogenicity of adult worms (mainly): ① Robbing nutrients and damaging intestinal mucosa (periumbilical pain) ②Hypersensitivity reaction (urticaria, skin itching) ③Complications: biliary ascariasis, ascariasis intestinal obstruction

direct smear method

Group deworming, health education, elimination of flies and cockroaches albendazole, mebendazole

The life history of roundworms is simple

Females lay large amounts of eggs

Fertilization with untreated human waste and open defecation practices

Bad human behavior and lack of adequate sanitation facilities

Insect eggs are highly resistant to the external environment

Infectious eggs (no internal migration, eggs are not as resistant as roundworms)

Ingestion by mouth with contaminated food or water

Cecum

Mucosal edema, rectal prolapse, anemia, gastrointestinal bleeding, right lower abdominal pain

direct smear method

Preferred are phenopyrimidines (humans are the only source of infection), albendazole, and mebendazole

Infectious eggs

Oral, inhalation, retrograde infection; contaminated hands, toys, linens, dust

Human cecum, colon and lower ileum

① Itching around the anus and night crying syndrome ②Pinworm appendicitis ③Pinworm genitourinary system and pelvic inflammation

Use the transparent tape method or the cotton swab method to collect eggs around the anus in the early morning before defecation or bathing.

Eggs are laid in places with high oxygen pressure and cannot be detected in feces.

The infected person is the only source of infection

Commonly used therapeutic drugs include albendazole and mebendazole, and pyrantel also has certain effects.

Filamentous larvae (thermotropic, hygrotropic)

Through the skin, through hair follicles, sweat glands or skin breaks

small intestine

Changing host: pig, dog, civet

Larvae pathogenic: hookworm dermatitis, respiratory disease

Pathogenicity of adult worms: Gastrointestinal symptoms: gastrointestinal bleeding, upper abdominal discomfort and pain, watery stools, tarry black stools, heterophilia; Anemia, moderate infection manifests as pale skin and mucous membranes

Causes of anemia: ① The worm sucks and excretes blood at the same time ②The head glands continuously secrete anticoagulants, causing blood to ooze from the adsorption site ③The insect body has the habit of changing its bite site, resulting in more wounds and the original wound still oozes blood. ④ Hookworms damage the intestinal mucosa, affect the absorption of nutrients, and aggravate the degree of anemia.

Hookworm disease in infants and young children: mostly caused by Ancylostoma duodenale

Saturated brine flotation method

Ancylostoma americana is the main species in the south, Ancylostoma duodenalis is the main species in the north, and the Yangtze River Basin is a mixed infection area where Ancylostoma duodenale is the main species.

Carriers and hookworm patients are the only sources of infection

The infection routes of infant hookworm disease are rarely through placental infection and breast milk transmission, but mostly through land or diapers contaminated with hookworms.

Treatment of hookworm dermatitis: intermittent soaking of the affected area in 53°C hot water

Commonly used anthelmintics: mebendazole and albendazole

larval cyst

Ingestion of meat containing live larvae in naan buns

Trichinella spiralis does not need to develop in the outside world to complete its life cycle, but it must switch hosts to grow and develop the next generation.

The parasite parasitized by Trichinella spiralis is both an intermediate host and a final host.

Zoonotic disease that parasitizes the duodenum and upper jejunum of the host

The larvae parasitize the skeletal muscle cells of the same host

invasion period

Larvae migration stage (most harmful)

cyst formation stage

Muscle slice biopsy method (not practical)

Tracing dining history, medical investigation, and medical history inquiry

Do not eat raw pork, strictly conduct meat quarantine, and strengthen feed management to prevent pig infection

Drug of choice: albendazole

3rd stage larvae

Infection caused by eating raw or semi-raw food containing intermediate hosts and secondary hosts of third-stage larvae

Eating raw vegetables contaminated with larvae and raw water containing larvae

Rats are the definitive host and humans are unsuitable hosts

Rat pulmonary artery, human philtrum retained in central nervous system

Three highs: high fever, high intracranial pressure, and high Eos Three pains: headache, muscle pain, and skin tingling acute meningoencephalitis

Routine laboratory examinations, immunological examinations, etiological examinations

Strengthen environmental sanitation and rodent control efforts

albendazole

mature cyst

trophozoite

Intestinal amoebiasis

Extraintestinal amoebiasis

Flask-like ulcer with small base and large mouth

Normal saline smear method (trophozoites)

Iodine smear method (cyst)

biopsy

Saline smear method, culture method