MEASLES VIRUS IMMUNITY LEVEL STUDY IN PARTICULAR POPULATION GROUPS OF THE REPUBLIC OF GUINEA WITHIN THE FRAMEWORK OF GLOBAL MEASLES ELIMINATION PROGRAM. REPORT 1

Measles remains one of the main reasons for child mortality in developing countries and periodically leads to the emergence of large outbreaks in different countries. This problem became especially urgent after WHO accepted the strategic plan to fight against measles. The plan has set the goal to decrease measles on a global scale. In 2010–2011 the large outbreaks of measles were registered on the African continent: in the Democratic Republic of Congo in the south of Africa, in Nigeria and in some other African countries. In the Republic of Guinea vaccination against measles is carried out singly to children aged 9 months. In 2014–2015 the increase of measles incidence was noted. Materials and methods. Using ELISA 22 blood serum samples of healthy adult Guineans aged 24–71 and 136 blood serum samples received from children and adults — the patients of hospital in the town of Kindi (Republic of Guinea) have been examined. The clinical samples were received in 2015–2016. The following test systems were used: the test systems produced by Euroimmun Medizinische Labordiagnostika AG (Germany): «Anti-Measles Virus ELISA (IGM)», «Anti-Measles Virus ELISA (IgG)»; «Avidity: Anti-Measles Virus ELISA (IgG)», and also ELISA Vector-Best IgM-measles test system (Russia). Results and discussion. Only one out of 22 examined healthy individuals hasn’t revealed IgG-antibodies to measles virus. The quantitative titre test of IgG-antibodies, and also their avidity among other 21 individuals testify experiencing measles in the recent or remote past. Having examined 116 blood serum samples of hospital patients in Kindi for IgM-measles-antibodies, the measles case with a 2.5-year-old child has been retrospectively revealed. Having examined 130 blood serum samples for IgG-antibodies to measles virus, 12.3% of seronegative to measles individuals have been revealed. All examined individuals aged 23 and older were seropositive to measles virus, and 60% of them had high antibody titres. The antibodies to measles virus were absent or were defined in low titres among 76.2% of people under 22, which can demonstrate violations of planned child vaccination due to the Ebola outbreak. In order to decrease the risk of emergence of large measles outbreaks in the areas, free from Ebola virus transmission, WHO recommends to conduct mass anti-measles vaccination campaigns.