What Are the Symptoms of Schistosomiasis?

Schistosomiasis is a chronic parasitic disease caused by Schistosoma japonicum. It is mainly prevalent in 73 countries in Asia, Africa, and Latin America, with about 200 million patients. There are two main types of schistosomiasis, one is intestinal schistosomiasis, which is mainly caused by Schistosoma mansoni and Schistosoma japonicum; the other is urinary tract schistosomiasis, which is caused by Schistosomiasis egyptes. The main epidemic in China is Japanese schistosomiasis.

Basic Information

nickname: Schistosomiasis of Japan
English name: schistosomiasis
Visiting department: Infectious Diseases

Common causes: Schistosomiasis
Common symptoms: Fever, gastrointestinal symptoms, hepatosplenomegaly, lung symptoms
Contagious: Have
way for spreading: Infected through contact with skin and mucous membranes

Causes of schistosomiasis

Source of infection

Feces of patients with Schistosoma japonicum contain live eggs and are the main source of infection.

2. Ways of transmission

Mainly through the skin, mucous membranes and infected water contact.

3. Susceptibility

Humans and vertebrates are generally susceptible to schistosomiasis.

Clinical manifestations of schistosomiasis

Invasion period

Patients may have cough, chest pain, and occasionally bloodshot sputum.

2. Acute phase

Clinically, it has the following characteristics:

(1) Fever is the main symptom of this period. The level of fever, duration and type of fever vary depending on the severity of the infection.

(2) Gastrointestinal symptoms are often dysentery-like stools with blood and mucus.

(3) Hepatosplenomegaly

(4) Coughing in the lungs is quite common, with chest pain, blood sputum and other symptoms.

3. chronic phase

Mostly, it is gradually found to be chronic because it has not been found in the acute stage, untreated or incompletely treated, or a small number of repeated infections. This period usually lasts 10 to 20 years. Due to the long course of the disease, the severity of the symptoms can be very different.

4. Late

The patient was extremely thin and had severe symptoms such as ascites, giant spleen, and abdominal wall veins.

Schistosomiasis test

Pathogen inspection

Examination of eggs or hatching hairy clams from the feces and rectal mucosal biopsies for examination of eggs.

(1) Schistosomiasis eggs can often be detected in the feces of patients with severe infections or in the mucus blood of patients with acute schistosomiasis by direct smear method .

(2) The maggot hatching method can increase the positive detection rate.

(3) Quantitative and transparent method is used for schistosomiasis egg count.

(4) Rectal mucosal biopsy . Intestinal wall tissues of chronic and advanced schistosomiasis patients are thickened, and the eggs are prevented from being excreted. Therefore, it is not easy to find eggs in the stool. Rectal microscopy can be used.

2. Immunity check

(1) Intradermal test (IDT) Generally, the coincidence rate between the intradermal test and the fecal test egg positive rate is about 90%, but false positive or false negative reactions may occur, which may have a high cross-reaction with other trematodes; and The patient can still be positive for years after healed. This method is simple, fast, and usually used to screen suspected cases on the spot.

(2) Detection of antibodies The presence of specific antibodies, including IgM, IgG, IgE, in the serum of patients with blood sucking patients. If the subject is not treated with the pathogen and the specific antibody is positive, it is of great significance in determining the diagnosis; Treatment, the specific antibody is positive, it is not certain that the subject still has adult parasites, because after the cure, the specific antibody can still be maintained in the body for a long time.

(3) Detection of circulating antigens Because antibodies remain in the host for a long time after treatment, their positive results often cannot distinguish between current infections and previous infections, and it is not easy to evaluate the efficacy. Circulating antigens are macromolecular particles discharged into the host body by living insects, which are mainly excreted, secreted or exfoliated by the insects. They have antigenic properties and can be detected by serum immunological tests. In theory, the detection of CAg has its own advantages. It can not only reflect active infection, but also evaluate the efficacy and estimate the species.

Schistosomiasis diagnosis

The diagnosis of schistosomiasis includes two parts: pathogen diagnosis and immunodiagnosis. The patient's diagnosis requires the detection of worm eggs or hatching hairy pupae from the stool.

Etiological diagnosis

Examination of schistosomiasis eggs and hairy pupae from the feces and rectal mucosal biopsy examination of the eggs is called the pathogenic examination, which is the basis for the diagnosis of schistosomiasis. Commonly used etiological examination methods include improved Kato method, nylon bag egg collection hatching method, plastic cup top tube hatching method and so on.

2. Immunological diagnosis

Immunological diagnosis includes detection of circulating antibodies, circulating antigens, and circulating immune complexes in patients' serum. Commonly used diagnostic methods include indirect red blood cell agglutination test (IHA), enzyme-linked immunosorbent assay (ELISA), colloidal dye test strip method (DDIA), and spot gold immunodiafiltration (DIGFA).

Differential diagnosis of schistosomiasis

Acute schistosomiasis

Must be distinguished from sepsis, malaria, typhoid and paratyphoid fever, acute miliary tuberculosis, viral infection, and other intestinal diseases. Mainly based on place of origin, occupation, epidemic season, history of exposure to epidemic water, high fever, hepatomegaly with tenderness, and increased eosinophils. Positive stool incubation is the main point of identification.

2. Chronic schistosomiasis

Must be distinguished from chronic bacillary dysentery, amoebic dysentery, ulcerative colitis, intestinal tuberculosis, rectal cancer and other diseases. A positive diagnosis of schistosomiasis hairy pupae from fecal hatching. Eosinophils are helpful in the diagnosis of this disease. Colonoscopy and tissue examination can help confirm the diagnosis. Routine stool examination, culture, X-ray barium enema, and diagnostic treatment are helpful for diagnosis and differential diagnosis.

3. Advanced schistosomiasis

Must be distinguished from portal cirrhosis and other causes of cirrhosis. The liver and splenomegaly, ascites, and abdominal wall veins caused by portal hypertension caused by schistosomiasis and liver cirrhosis are more prominent, liver cell function changes are lighter, and the liver surface is uneven. Portal vein cirrhosis is characterized by fatigue, anorexia, jaundice, angioma, hepatomegaly that is marked or even reduced, it is not easy to touch the surface nodules, and there are changes in active liver function, such as increased transaminase.

4. Ectopic Schistosomiasis

Pneumoschistosomiasis must be distinguished from bronchitis, miliary tuberculosis, and pulmonary schistosomiasis. Acute cerebral schistosomiasis should be distinguished from Japanese encephalitis. Chronic cerebral schistosomiasis should be distinguished from brain tumors and epilepsy.

Urinary dermatitis needs to be distinguished from rice field dermatitis. Paddy dermatitis is caused by schistosomiasis cercariae parasitizing in the portal vein of cattle, sheep, ducks and other animals to invade the skin. It is more common in provinces and cities in southeast, northeast and southwest China. The host ovulates into the water, hatches the hairy maggots, enters the cone snail, and the tail tail maggot escapes the snail body. People come into skin immediately after contacting cercaria, causing dermatitis. Dermatitis showed red spots at first, and gradually expanded to red papules. The rash subsided one week later, the cercaria was eliminated, and the lesions no longer developed.

Schistosomiasis complications

Complications are more common in chronic and advanced cases, and more common in appendicitis.

Schistosomiasis patients with acute bacterial appendicitis are likely to cause perforation, appendicitis abscess, and worm egg deposition in appendicitis tissue. Appendiceal perforation is likely to cause diffuse peritonitis complications.

Patients with schistosomiasis can develop colonic strictures when their colon lesions are severe, causing difficulty in defecation and other symptoms of intestinal obstruction.

It is not uncommon for cancer to develop on the basis of schistosomiasis intestinal proliferative lesions.

Schistosomiasis treatment

1. Support and symptomatic therapy

Patients with persistent high fever in the acute phase may first use adrenocortical hormones or antipyretics to relieve symptoms of poisoning and cool down. For chronic and advanced patients, nutrition should be enhanced to give a high-protein diet and multivitamins, and attention should be paid to the treatment of anemia. When liver cirrhosis has portal hypertension, liver treatment and surgical treatment should be enhanced. People with other intestinal parasitic diseases should be treated with deworming.

2. Pathogen treatment

(1) Praziquantel This drug is currently the drug of choice for the treatment of schistosomiasis. It can kill larva, larva and adult. The cure rate for acute schistosomiasis is high. The side effects are few and mild, including dizziness, fatigue, sweating, and mild abdominal pain.

(2) Artemether and artesunate can also be used to treat schistosomiasis.

Schistosomiasis prevention

1. Do not swim or swim in lakes, river ponds, or canals with snail distribution.

2. Those who are unavoidable to come into contact with the epidemic water due to production and life can apply protective ointment before contacting the epidemic water to prevent schistosomiasis infection.

3. After contact with the epidemic water, go to the local schistosomiasis department to conduct necessary inspections and early treatment in time.