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Serum meningococcal antibodies
Medical expert of the article
Last reviewed: 05.07.2025
The diagnostic titer of antibodies to meningococcus for RPGA is 1:40 (1:20 in children under 1 year) and higher.
The causative agent of meningococcal infection is the gram-negative diplococcus Neisseria meningitis. There are five serological types of meningococcus: A, B, C, D and E. During epidemics, type A predominates, and during the non-epidemic period, type B. In the diagnosis of meningococcal infection, the main place is occupied by the bacteriological method of research. However, the cultivation of meningococci and their isolation in pure culture is successful only in 30-40% of cases. In this regard, serological methods are used for diagnosis - detection of Neisseria meningitis antigens in cerebrospinal fluid or antibodies in blood serum. A number of methods are used to detect antibodies, the most sensitive and informative of which are RPGA and ELISA, in which group-specific polysaccharides are used as antigens.
The patient's blood serum is examined on the 1st-3rd day from the onset of the disease and on the 7th-10th day. An increase in the antibody titer by at least 4 times after 7-10 days is considered diagnostic. Usually, from the 5th-6th day of the disease, the antibody titers detected in the RPGA reach 1:200 and higher.
Detection of antibodies to meningococcus is used to diagnose meningococcal infection, bacterial and serous meningitis, and urethritis.
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