Typical cases of measles can be diagnosed on the basis of clinical symptoms without laboratory tests. For mild and atypical cases, microbiological examination is needed to confirm the diagnosis. Because the method of virus isolation and identification is complex and time-consuming, requiring at least 2 to 3 weeks, serological diagnosis is used.

virus isolation

Blood, pharyngeal lotion or throat swab of patients at the early stage of the disease were treated with antibiotics and inoculated into human embryonic kidney, monkey kidney or human amniotic cell culture. Virus proliferation was slow, and typical CPE appeared after 7 to 10 days, that is, multinucleated giant cells, intracellular and nuclear eosinophilic inclusion bodies. Then immunofluorescence was used to identify measles virus antigen in inoculated culture.

Serological diagnosis

Double serum samples were taken from patients in acute stage and convalescence stage, and HI test was often performed to detect specific antibodies, CF test or neutralization test could also be used. When the antibody titer is increased by more than 4 times, it can assist clinical diagnosis. In addition, IgM antibodies can also be detected by indirect fluorescent antibody method or ELISA.

Rapid diagnosis

The presence of measles virus antigen in mucous cells of catarrhal pharyngeal gargle was examined with fluorescentially labeled antibody. Viral nucleic acids in cells can also be detected by nucleic acid molecular hybridization.