Collective Immunity to Virus Measles of Medical Workers and Students of Medical Colleges in the Republic of Tatarstan

Relevance. Within the framework of the state assignment in the, Kazan Scientific Research Institute of Epidemiology and Microbiology together with the Department of Rospotrebnadzor in the Republic of Tatarstan, the analysis of the tensions of collective immunity to measles in at-risk groups among medical workers, students of medical colleges in Kazan, Naberezhnye Chelny, Buinsk and Muslyumovsky districts for the period 2015‒2017.

Materials and methods. Immunoenzyme method of analysis studied the intensity of immunity against measles in 1107 serum samples of medical workers from 19 medical and preventive institutions in cities and some regions of the Republic of Tatarstan, and students of medical schools and colleges.

Results. It was established that out of 480 medical personnel, 363 (75,63 ± 2,253%) were seropositive to the measles virus, and 117 (24.38 ± 3.969%) were seronegative. Coverage by vaccination and revaccination against measles among the sample group of medical workers did not reach the level of 93% (84.38 ± 1.657%), which does not prevent the outbreak of measles among this group. According to the results of a sample survey of antibodies to measles virus among students of medical schools and colleges of the Republic of Tatarstan (data for 2016 and 2017), it was found that the proportion of seronegative measles virus among students in large cities of the Republic of Tatarstan in 2016 was 52.35 ± 2,99%, and in 2017, 42.32 ± 2.958% of the people. The proportion of students who were seronegative for measles virus for two years of the study (2016–2017) averaged 45.07 ± 2.979%.

Discussion and conclusions. The results indicate the need to continue conducting studies on seromonitoring of collective immunity to measles in medical workers, students in secondary and higher medical schools.

1. WHO Regional Office for Europe. Available at: http://www.euro.who.int/ru/media-centre/sections/press-releases/2018/europe-observes-a-4-fold-increase-in-measlescases-in-2017-compared-to-previous-year Accessed: 15 Nov 2018.

2. State of sanitary and epidemiological welfare of the population in the Russian Federation in 2015: State report. Federal Service for Surveillance on Consumer Rights Protection and Human Wellbeing (Rospotrebnadzor). Moscow; 2016. P. 113–145. (In Russ.)

3. State of sanitary and epidemiological welfare of the population in the Russian Federation in 2016: State report. Federal Service for Surveillance on Consumer Rights Protection and Human Wellbeing (Rospotrebnadzor). Moscow. 2017; P. 133–145. Available at: http://rospotrebnadzor.ru/documents/details.php?ELEMENT_ID=8345Accessed: 15 Nov 2018. (In Russ.)

4. Methodological instructions MU 3.1.2943-11. Organization and conduct of serological monitoring of the state of collective immunity to infections controlled by means of specific prevention (diphtheria, tetanus, whooping cough, measles, rubella, mumps, poliomyelitis, hepatitis B). (In Russ.)

5. Ackley SF, Hacker JK, Enanoria WTA, et al. Genotype-Specific Measles Transmissibility: A Branching Process Analysis. Clin Infect Dis. 2017. doi: 10.1093/cid/cix974

6. Andani CJ, Castaneda GP, Fuente GM, et al. Serological survey of measles, rubella and mumps immunity among pediatric and resident physicians, Valencia, Spain. Rev Esp Salud Publica. 2014;88(5):653–659.

7. Chen CJ, Lee PI, Hsieh YC, et al. Waning population immunity to measles in Taiwan. Vaccine. 2012;30:6721–6727.

8. Choe YJ, Park YJ, Kim JW, et al. An outbreak of measles in a University in Korea, 2014. J Korean Med Sci. 2017;32(11):1876–1878.

9. Measles vaccines: WHO position paper – April 2017. Wkly Epidemiol Rec. 2017;(17)92:205–228.

10. Newcombe RG. two-sided confidence intervals for the single proportion: comparison of seven methods. Statistics in Medicine. 1998;17:857–872.

11. Rathi P, Narendra V, Sathiya V, et al. Measles Outbreak in the Adolescent Population – Matter of Concern? J Clin Diagn Res. 2017;11(8):LC20–LC23.

12. Seagle EE, Bednarczyk RA, Hill T, et al. Measles, mumps, and rubella antibody patterns of persistence and rate of decline following the second dose of the MMR vaccine. Vaccine. 2018;pii:S0264–410X(17)31838–8.