What is Giardiasis?

Giardia lamblia is commonly known as Giardiasis, a protozoal disease caused by Giardia lamblia in the human small intestine. Clinically, diarrhea, abdominal pain and bloating are the main manifestations, and can cause cholecystitis, cholangitis and liver damage. In addition to the endemic epidemic, the disease can also cause water-borne outbreaks. Infections are also common among tourists. In recent years, it has been found that AIDS patients can often be infected with local worms.

Basic Information

English name: giardiasis
Visiting department: Internal medicine
Multiple groups: AIDS patient

Common locations: Intestine
Common causes: Giardia trophozoite
Common symptoms: Diarrhea, abdominal pain and bloating

Causes of Giardiasis

Giardia trophozoites are firmly adsorbed on the mucous membranes of the duodenum and proximal jejunum and reproduce in two divisions. The released worms quickly transform into cysts that are resistant to the external environment. After the cysts are discharged with the feces Transmission via fecal-oral route, waterborne infection is the main source of Giardiasis. In addition, it can be directly transmitted through human-to-human contact. In addition to humans, wild animals can become their insect-preserving hosts. Therefore, mountain streams and urban water supply systems that have been chlorinated but not strictly filtered are the source of waterborne epidemics.

Clinical manifestations of Giardiasis

The incubation period is generally 1 to 3 weeks, with an average of 9 to 15 days. The clinical manifestations are mainly gastrointestinal symptoms. The typical symptoms of the acute stage are fulminant diarrhea, watery stools and foul odor, and a small amount of mucus, but most of them are free of pus and blood. Patients are often accompanied by nausea, vomiting, bloating, belching, and abdominal pain are common. Some patients have systemic symptoms such as low fever, chills, headaches, fatigue, and loss of appetite.

The acute phase lasts for several days. If the treatment is not timely, it may turn into a subacute infection, which mainly manifests as intermittent diarrhea, abdominal pain, and loss of appetite. It can last for several months. The chronic phase is mainly manifested by repeated episodes or persistent loose stools. For periodic short-term diarrhea, stools are loose stools with yellow foam floating on the surface, foul odor, mostly less than 10 times per day, bloating, belching, anorexia, nausea, but abdominal cramps are rare, and the course can often last for several years.

Childhood cases and severely infected persons can lead to weight loss, weight loss, developmental disorders, anemia, etc. due to long-term malabsorption. When the worms invade the gallbladder and bile duct, the patient presents with symptoms of cholecystitis and bile duct inflammation, pain in the right upper abdomen or under the xiphoid process, Nausea, vomiting, fever, tenderness in the gallbladder, etc., the lesions involve the liver. Patients with liver pain, large liver with tenderness and liver function damage are the main manifestations. In addition, some patients may show gastritis, appendicitis, etc.

Giardiasis test

Pathogen inspection

The trophozoites can be found in fresh diarrhea, cysts in pasty stools and shaped stools. The trophozoites can be found by directly staining the stool with normal saline; the cysts can be easily identified after staining with iodine, zinc sulfate floating method, etc. Concentration method can increase the detection rate of cysts. Fecal examination should be sent three times and three times. The positive rate of three times can be increased to 97%. The duodenum drainage, small intestinal mucus or biopsy tissue can be found in the worm.

2. Immunological test

Can be divided into two types of detection of serum antibodies and fecal antigens.

(1) Detection of antibodies Since the successful culture of Giardia lamblia, since the preparation of high-purity antigens has become possible, the sensitivity and specificity of immunodiagnosis have been greatly improved. Two strains of Giardia lamblia have been established in China The culture provides conditions for the development of immunodiagnosis in China. Enzyme-linked immunosorbent assay (ELISA) and indirect fluorescent antibody test (IFA) check the serum antibodies of patients.

(2) Enzyme-linked immunoassay (double-sandwich method), dot enzyme-linked immunosorbent assay (Dot-ELISA), and convection immunoelectrophoresis (CIE) can be used to detect antigens in fecal dilutions. The detection of fecal antigens can be used for diagnosis. You can also observe the effect.

3. Molecular biology diagnosis

In recent years, polymerase chain reaction (PCR) has been used to detect the gene product of ribosomal RNA (rRNA) of Giardia lamblia. It can detect an amplified copy equivalent to the genomic DNA of a trophozoite, and radiolabeled chromosomal DNA probes are also available. Detection of trophozoites and cysts, molecular biology methods are highly specific and sensitive.

4. Other inspections

B-ultrasonography of the abdomen understands the liver and gallbladder. X-ray chest and electrocardiogram should be done.

Giardiasis diagnosis

According to the patient's diarrhea, bloating, upper abdominal pain or discomfort, fecal stench, and the general diagnosis of Giardia lamblia is not difficult. Diagnosis can be made by finding characteristic trophozoites or cysts in the feces. These worms are easy to find in the acute phase, but they are excreted intermittently at low levels during the chronic infection period. Therefore, repeated fecal examinations or nylon sutures or endoscopy to obtain the upper small intestine contents to check the worms, Immunofluorescence test and enzyme-linked immunosorbent assay can also be used to detect Giardia or Giardia antigen in feces, as well as specific DNA probe technology.

Giardiasis differential diagnosis

Should consider amoebic dysentery, bacterial dysentery or other causes of gastroenteritis, abdominal pain, hepatic tenderness, and liver function impaired, consider cholecystitis, biliary infection and viral hepatitis. Flagellates are an important step in identification.

Giardia complication

Water and electrolyte disorders can occur, which can cause anemia and malnutrition, and retarded growth.

Giardiasis Treatment

Patients should be isolated according to intestinal infectious diseases and control their diet. Antibiotics should be given for bacterial infections. Anti-pathogenic drugs should be given to confirmed patients and those who are highly suspected of the disease. The drugs available are:

Metronidazole

Generally, the protozoa in the feces can turn negative after 3 days of taking the medicine, and the symptoms gradually disappear. Common toxic and side effects include oral metal taste, nausea, burnout, and lethargy. Alcohol should be banned while taking the drug, and pregnant and lactating patients are prohibited.

2. Furazolidone.

3. Albendazole

Is a very promising anti-Gardens flagellans drug.

4. Praziquantel

The therapeutic effect of this drug has yet to be determined by further research.

5. Other

Researchers abroad have used tinidazole and nimozole, while domestics have Sophora flavescens extracts for the treatment of this disease.

Giardiasis prevention

Strengthen water sanitation management, pay attention to food hygiene, thoroughly treat patients and asymptomatic cyst carriers, eliminate cockroaches, flies and other transmission vectors, do harmless treatment of feces, and maintain normal immune function, etc., all to prevent the occurrence or epidemic of the disease Important measures. Water can be boiled or heated to 70 ° C for 10 minutes to achieve the purpose of disinfection.