Serological tests

Antibodies to streptococcus A, B, C, D, F, G in the blood

Antibodies to the group-specific polysaccharide polysaccharide (anti-A-CHO) appear in the first week of infection, their titer rapidly increases, reaching a peak at week 3-4 of the disease.

Infectious erythema: antibodies to parvovirus B19 in the blood

Antibodies IgM to parvovirus B19 are detected in 90% of patients 4-7 days after clinical manifestations of the disease. The number of antibodies gradually increases reaching a maximum by 4-5 weeks, and then decreases. Antibodies IgM IgM to parvovirus B19 can persist in the blood for 4-6 months after the disease.

Coxsackie-infection: antibodies to Coxsackie viruses in the blood

With the use of RSK, RTGA and neutralization reaction, antibodies to Coxsackie viruses in serum are detected. Investigate paired sera in the acute period of infection and 2-3 weeks after the onset of the disease.

Antibodies to the respiratory syncytial virus in the blood

To detect antibodies to the respiratory syncytial virus, DSC or ELISA is used. In DSC, the study is carried out at the onset of the disease and after 5-7 days, it is diagnostically significant that the antibody titer increases by at least 4 times in the study of paired sera, but this test method is less sensitive in children under 4 months of age.

Adenovirus infection: antibodies to adenoviruses in the blood

To detect antibodies to adenoviruses, use of DSC or ELISA is used. With RBC, the study is carried out at the onset of the disease and after 5-7 days, the increase in titer of antibodies is considered to be diagnostically significant no less than 4 times when studying paired sera.

Parainfluenza: antibodies to parainfluenza virus types 1, 2, 3 and 4 in the blood

Compared with the RSK, the ELISA method (which makes it possible to detect antibodies of IgM and IgG types) is more sensitive (according to different authors, from 49% to 94%). However, as with RSK, for use in the diagnostic purposes of ELISA, comparison of antibody titers in serum samples obtained from patients at the beginning and at the end of the disease is necessary.

Influenza: antibodies to the influenza A and B virus in the blood

For the detection of antibodies to influenza viruses, DSC or ELISA is used. When RBC study is carried out at the beginning of the disease (1-2 days) and after 5-7 days, the diagnostic is considered to increase antibody titer no less than 4 times when examining paired sera.

Rubella: antibodies of class IgM and IgG to the rubella virus in the blood

IgM antibodies to the rubella virus appear in the acute period of infection: on the first day of rashes - in 50% of patients, in 5 days - more than 90%, in 11-25 days - in all patients.

Viral parotitis: IgM antibodies to mumps virus in the blood

IgM antibodies to mumps virus appear in the acute period of infection (on the second day of the disease they are detected in 70% of patients, by the 5th day - at 100%) and persist up to 2 years (in 50% of patients - more than 5 months). Detection of IgM antibodies in the serum or an increase in IgG antibody titer in paired sera more than 4 times (sensitivity 88%) indicates a current infection.

Measles: antibodies IgM and IgG to measles virus in the blood

IgM antibodies to measles are detected in the acute period of infection (within 6 days after the onset of the rash - in 80%, in 7 days - in 95% of patients), they peak at 2-3 weeks, hold for 4 weeks and then gradually disappear (50% of patients become seronegative after 4 months). IgG antibodies to measles appear in the period of convalescence, in those who have recovered they persist up to 10 years.

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