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UDC 616.831.9-002:616.157-036.22 (571.15)
CURRENT EPIDEMIOLOGICAL SITUATION ON BACTERIAL MENINGITIS IN ALTAI KRAI
1 Altai State Medical University, Barnaul
2Regional reference center of bacterial meningitis monitoring
Yu.A. Kozyanova1, T.V. Safyanova1, S.V. Shabanova2
There was performed the assessment of current situation on bacterial meningitis morbidity in Altai Krai for the period of2011-2016 and revealed some peculiarities of the epidemic process in the territory of the region. Key words: bacterial meningitis, retrospective analysis, pneumococcal disease, morbidity.
Streptococcus pneumoniae is a widespread etiologic agent causing a large range of human infectious diseases, which is connected with an abundance of serotypes preconditioning the duration of carriage and development of severe forms of diseases [1; 4]. Meningitis, as one of the clinical forms of pneumococcal disease, is the issue of concern of the whole world, as it causes over 60 thousand deaths per year and a high level of disability among children under 5 years old [3]. The ratio of etiologic pathogens to meningitis is not always the same and depends on climatic conditions, the level of immunoprophylaxis, territory, specifically the tension of epidemiological situation. In Altai Krai, the spread of pneumococcal disease has not been studied as well as in the Russian Federation on the whole, and it has determined the objective of this work.
Research objective is the assessment of current epidemiological situation on bacterial meningitis (hereinafter BM) morbidity in Altai Krai population in 2011-2016.
Materials and methods
Retrospective epidemiological analysis of BM morbidity is based on data of official statistics of Ministry of Health in Altai Krai using the report form No 12 "Records on the number of diseases registered among patients living in the area of medical organization service" and data of Regional reference center of bacterial meningitis monitoring.
The materials of research were subjected to statistical processing. The calculation of extensive and intensive morbidity rates, coverage errors (m), average data (X), Student's t-test has been made. In all statistical analysis procedures, the critical significance level was taken as 0.05.
Results and discussion
For the period from 2011 to 2016, a tendency to bacterial meningitis morbidity reduction is observed in Altai Krai population (figure 1). Thus, in 2016 morbidity rate was 1.4±0.25 per 100 thousand of population, in 2011 the rate was 3.8±0.40 per 100 thousand of population. The peak of morbidity was found in 2011 and amounted to 3.8±0.40
per 100 thousand of population. The average long-term bacterial meningitis morbidity rate for the period under study was 2.1±0.12 per 100 thousand of population. For the period of 2011-2016, the rate of decrease was 63.2 per cent, the average annual rate of decrease was 10.5 per cent. However, for the period from 2015 to 2016, the morbidity rate increased by 27.3 per cent from 1.1±0.22 per 100 thousand of population in 2015 to 1.4±0.25 per 100 thousand of population in 2016.
When assessing BM morbidity rate in various age groups, it was found that in the period under study, the highest average morbidity rate was registered among children (from 0 to 14 years) and amounted to 2.9±0.35 per 100 thousand of the corresponding population. The average morbidity rate among adolescents (from 15 to 17 years) was equal to 0.8±0.43 per 100 thousand of the corresponding population. From 2012 to 2016, no cases of BM morbidity among adolescents were registered. The morbidity rate among adults (18 years and more) averaged 1.5±0.11 per 100 thousand of the corresponding population (figure 2).
For the period of 2011-2016, the majority of people having bacterial meningitis was among adult population 76.2±2.45 per cent (figure 3). Among adolescents, this percentage was 1.0±0.57 per cent. The average percentage of children having bacterial meningitis was 22.8±2.42 per cent.
In 2014, in Altai Krai Regional reference center of bacterial meningitis monitoring was created, where bioassays from patients with bacterial meningitis were sent from around the region. According to the center's report, the average percentage of etiologic agent detection in the obtained samples was 54.7±6.84 per cent (Table 1). In the isolated cultures, the share of meningococcal meningitis was 44.8±9.23 per cent, the share of pneumococcal meningitis was 55.2±9.23 per cent.
Conclusion
By the results of the assessment of current ep-idemiological situation on BM morbidity, it can be concluded that in Altai Krai for the period from 2011 to 2016 bacterial meningitis morbidity had a general tendency to decrease. However, for the
4,5
0,5 0,0
2011 2012 2013 2014 2015 2016
-Morbidity in Altai Krai ^—Lineal (Morbidity in Altai Krai)
Figure 1. The dynamics of bacterial meningitis morbidity in Altai Krai for the period of 2011-2016
(per 100 thousand of population)
6 4 2 0
V 4 o
2,8 \ 1 7
0,4 N i 1,3 1 4
\ 0.0 _QJL_ -QE—Q,o
2011 2012 2013 2014 2015 2016 -Children -Adolescents — Adults
Figure 2. The dynamics of bacterial meningitis morbidity among various age groups in Altai Krai for the period of 2011-2016. (per 100 thousand of the corresponding population)
100% 90%
50% 40% 30% 20% 10% 0%
-
73,9 74,3 75,6 73,3 79,4
88,9
3 3 00 0,0 0.0
0,0
22,8 25,7 ?4.4 26,7 0,0 20,6
11,1
2011 2012 2013 2014 2015 ■ Children ■ Adolescents ■ Adults
2016
Figure 3. Specific weight of patients with acute otitis media by age groups in Altai Krai for the period of 2011-2016 (at percentage)
io
Table 1
The etiological structure of bacterial meningitis in Altai Krai for the period of2014-2016
Among them:
Year Samples (pcs) Positive result (pcs) N. meningitidis Str. Pneumoniae
Gr. A Gr. B Gr. C Total
2014 6 6 - 3 1 4 2
2015 23 8 - 3 - 3 5
2016 24 15 - 3 3 6 9
Total 53 (100%) 29 (54,7%) 13 (44,8%) 16 (55,2%)
period from 2015 to 2016 the morbidity rate increased by 27.3 per cent. The highest BM morbidity rate was among children and amounted to 2.9±0.35 per 100 thousand of the corresponding population. Adult population made the main contribution to the structure of patients with BM, the specific weight equaled to 76.2±2.45 per cent. Pneumococ-cal disease took the leading position in BM etiology in the area for the period under study. In Altai Krai, there is no pneumococcal disease epidemiologi-cal surveillance system. These results confirmed the necessity of its development and implementation in the territory of a large area.
References
1. Lobzin Yu.V. et al. Serotypes of Streptococcus pneumoniae causing major pneumococcal infections. Journal Infectology. 2013; 5(4): 36-42.
2. Kharit S.M., Perova A.L. Modern approaches to the prevention of pneumococcal infection. Meditsinsky sovet. 2015; 16: 64-67.
3. O'Brien K.L. et al. Burden of disease caused by Streptococcus pneumoniae in children younger than 5 years: global estimates. Lancet. 2009; 374: 893-902.
4. Sakai F. et al. Single-plex quantitative assays for the detection and quantification of most pneumococcal serotypes. PloS one. 2015; 10(3): 4754.
Contacts
Corresponding author: Kozyanova Yulia Ana-tolyevna, post-graduate student of the Department of epidemiology, microbiology and virology of ASMU, Barnaul. 656056, Barnaul, ul. Papanintsev, 126. Tel.: (3852) 566924. E-mail: ykozyanova@yandex.ru
