Viral diarrhea

Introduction Viral gastroenteritis, also known as viral diarrhea, is a group of acute intestinal infections caused by a variety of viruses. The clinical features are acute onset, nausea, vomiting, abdominal pain, diarrhea, drainage or loose stools, fever and general malaise, short duration and low mortality. The clinical manifestations of gastroenteritis caused by various viruses are basically similar. There are many types of viruses associated with acute gastroenteritis, among which the more important ones are rotavirus and Norwsalk-like virus.

Cause

Most of them are caused by rotavirus infection, which is often called "autumn diarrhea" because it occurs in autumn and winter.

Rotavirus is a family of reoviruses that are spherical and have a wide-shell, short- and thin-sided double-stranded RNA virus. The average diameter is about 70 nm, and the center of the virion is a dense core with a diameter of 36 to 45 nm, containing viral nucleic acids. There is a double-layered polypeptide capsid that has a rim shape and surrounds the inner layer. The inner layer of the shell particles are radially arranged at the edge and resemble a wheel strip, so it is called a rotavirus. The central part of the grain is irregularly arranged and has a honeycomb shape. Under the electron microscope, rotavirus has two forms, namely, double-shell particles and single-shell particles. The former is a mature or intact virus particle with an outer polypeptide capsid, also known as light Virion, which is infectious; the latter loses its outer shell under natural conditions, forming a rough single-shell particle. Also known as D virion (dense virion), non-infectious. The human shell of the rotavirus can cross-react with the rotaviruses of calves, mice, piglets, lambs, rabbits and monkeys, but the coat antigen is specific. Human rotavirus has at least 4 serotypes, and there is no cross-protection between the various types.

The rotavirus gene contains 11 segments of double stranded RNA. According to the RNA electrophoresis pattern, human and animal viruses are currently classified into A to D groups. Group A is a common rotavirus (mainly causing diarrhea in infants and young children); group B is porcine rotavirus and adult diarrhea rotavirus, the latter is the adult prevalence of Chinese scholars from all over China in 1984. A new rotavirus isolated from patients with diarrhea, the virus and the rotaviruses found in other parts of the world are collectively referred to as antigen-specific rotavirus; group C is human and porcine rotavirus; Group D is chicken and bird rotavirus. Adult diarrhea rotavirus and common human rotavirus have differences in viral antigenicity, nucleic acid pattern and clinical manifestations.

Rotavirus is more resistant to physical and chemical factors, resistant to ether and weak acid, can be stored for a long time at -20 ° C, and can be inactivated at 56 ° C for 1 hour. This virus can be passaged and propagated in monkey kidney primary cells.

an examination

Related inspection

Conventional urinary citrullinase-linked immunosorbent assay

1. Blood routine: The total number and classification of peripheral blood leukocytes are mostly normal, a few are high, and the classification of lymphocytes increases.

2. Stool routine and culture: Most of the stool examinations have no special findings, and a small number of white blood cells can be seen, and no pathogenic bacteria grow.

3. Specific diagnostic experiments:

(1) taking feces for direct or immunoelectron microscopy, rotavirus particles can be found;

(2) The detection of viral antigen in fecal supernatant by enzyme-linked immunosorbent assay or immunoenzymatic plaque assay (Immnnoenzymedottest) has high sensitivity and specificity;

(3) Extracting viral RNA from feces, performing polyacrylamide gel electrophoresis and silver staining, and checking the presence or absence of rotavirus RNA electropherogram, which has both diagnostic value and different types of virus infection;

(4) Serological test, 5 days after infection, specific IgM antibodies can be detected in the blood, which is also helpful for the diagnosis of this disease.

Differential diagnosis

The disease should be differentiated from bacterial diarrhea: usually the majority of diarrhea is caused by virus or indigestion. Generally speaking, bacterial diarrhea is often referred to as bacillary dysentery. It is contagious. Of course, some babies have poor resistance. Long-term diarrhea can also be followed by bacterial infections such as E. coli, mold, etc., but not much. Regarding the treatment method, in addition to symptomatic treatment, it helps digestion, diarrhea, and anti-inflammatory.

The main features of autumn diarrhea: first vomiting and diarrhea, accompanied by fever, stool is watery or egg-flower soup, the course of disease is self-limiting, that is, the use of drugs can not significantly change the course of disease, symptoms:

(1) Acute onset, often accompanied by cold symptoms, such as cough, stuffy nose, runny nose, half of the children will also have fever (common in the early stage of the disease), generally low fever, rarely high fever.

(2) Increased stool frequency, about 10 times a day, more than 3 times should consider autumn diarrhea, stool white, yellow or green egg flower soup, with a little mucus or pus, no odor.

(3) Half of the children will have vomiting. Most of the symptoms of vomiting occur in the early stages of the disease, usually no more than 3 days.

(4) Dehydration symptoms may occur in patients with severe diarrhea, such as thirst, decreased urine output, and irritability.

(5) The course of the disease is self-limiting, the course of the disease is generally 5-7 days, malnutrition, rickets and frail patients, diarrhea may take longer.

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.