Astrovirus – antigen determination

• The stool is delivered to the laboratory for examination within 2 hours of collection. If the delivery time exceeds 2 hours, it is necessary to use containers with a preservative for transporting the material.
• The container with feces is tightly closed with a lid, packed in a clean disposable bag and delivered to the laboratory.
• Stools should not be submitted for testing after an enema, suppository insertion, or castor oil administration. Stools for testing should not contain foreign substances, such as urine.
• In newborn babies, feces are collected from the diaper or nappy immediately after defecation.

Astroviruses, which belong to the Astroviridae family, are among the major pathogens causing gastrointestinal diseases in humans and animals. These viruses have several species and serotypes that can cause different forms of disease. Diagnosis of astroviral infections is an important task for medical laboratories and clinical settings. One of the key diagnostic methods is the detection of astroviral antigens.

Astroviruses: general information

Astroviruses are small, spherical, lipid-enveloped RNA viruses. Their genome consists of a single large polypeptide that encodes all the essential proteins of the virus. Astroviruses produce several structural proteins, including a capsid protein, which is the main antigen for diagnosis.

Diagnosis of astroviral infections

Diagnosis of astroviral infections is usually based on the detection of antigen present in the patient. There are various methods for detecting astroviral antigen, such as enzyme-linked immunosorbent assay (ELISA), immunofluorescence microscopy, and polymerase chain reaction (PCR).

1. Enzyme-linked immunosorbent assay (ELISA): This method is based on the specific interaction between antibodies to astroviruses and viral antigens. The patient's blood sample interacts with plates on which antibodies to astroviruses are fixed. If the virus antigens are present in the analyzed sample, they will interact with the antibodies, which will lead to the measurement of a color reaction, indicating the presence of infection.
2. Immunofluorescence microscopy: This method uses fluorescent antibodies that specifically bind to astrovirus antigens in the sample. After the antibodies interact with the antigens, they become visible under a microscope under fluorescent light.
3. Polymerase chain reaction (PCR): PCR is a highly sensitive method for detecting viral genetic material. This method uses specific primers to amplify astrovirus RNA in a sample. After amplification, gel electrophoresis can be performed to determine the presence of the viral genome.

Final thoughts

Diagnosis of astroviral infections is important for early detection and control of these diseases. Detection of astroviral antigens is an effective diagnostic method that allows for early detection of infection and initiation of treatment. Development of more sensitive and specific diagnostic methods will help improve control of astroviral diseases and prevent their spread.