UDC 614.446:616.24-002(571.15)
CURRENT EPIDEMIOLOGICAL SITUATION OF COMMUNITY-ACQUIRED PNEUMONIA IN ALTAI KRAI
Altai State Medical University, Barnaul Yu.A. Kozyanova, T.V. Safyanova
The aim of the study is to assess the current epidemiological situation of community-acquired pneumonia in child and adult population in Altai Krai in 2011-2015. Conducting a retrospective analysis of the incidence of community-acquired pneumonia (CAP) we found out that this disease is a significant problem for Altai Krai because since 2014 the incidence rate of CAP in Altai Krai (AK) was higher than the incidence rate of CAP in Russia. The incidence rate of CAP in children was higher than in teenagers and in adults both in AK and in the Russian Federation. According to the results of laboratory tests, we noticed the percentage increase of pneumococcal CAP. Key words: community-acquired pneumonia, pneumococcal infection, retrospective analysis.
Community-acquired pneumonia (CAP) is a common disease and a common cause of death in people of any age all over the world [1, 2]. The types of CAP causative agents vary depending on age, and respiratory viral infections more often take place in infants [2, 3]. Pneumococcus is one of the main bacterial causative agents of CAP in all age groups after neonatal period and it is often associated with complications [4, 5]. Wide occurrence of this bacterium is explained by a large number of its serotypes [6, 7]. Today there are more than 93 known pneumococcus serotypes which are characterized with long-term carriage and the development of severe forms of diseases [8]. Among all these serotypes, about 20 of them cause more than 80% of pneumococcal diseases all over the world. This problem is important today in the Russian Federation (RF) because among all children under five years old admitted to hospital with pneumonia 47% of them had S. pneumonia in their nasopharyngeal swabs [9]. In risk groups, the incidence rate of diseases caused by this microorganism is 5-100 times higher than the incidence rate in the population at large. These groups consist of children under 5 years old (especially under 2 years old), people over 65 years old and patients with some chronic diseases regardless of their age [8]. This infection is not well enough studied in Altai Krai (AK) but respiratory diseases occupy a dominant position in the incidence structure in child population.
Research objective: the aim of this study is to assess the current epidemiological situation of community-acquired pneumonia in child and adult population in Altai Krai in 2011-2015.
Materials and methods
The subject of the study is represented by main mechanisms of the development of the epidemic process of community-acquired pneumonia in Altai Krai. There was conducted a retrospective analysis of the incidence rate of community-acquired pneumonia. The total number of reported cases of this dis-
ease was 38663 cases during 2011-2015. In the course of our study, we conducted a retrospective analysis of the dynamics of the long-term incidence of CAP in AK and the RF. There was performed the statistical analysis of the study materials. For statistical analysis, there was used STATISTICA 10.0 and MS Excel 2010. Mean sample values for quantitative variables are specified as M±m (M - a sample mean and m - a standard error of the mean). A paired t test was employed for the assessment of statistical significance (p). The level of significance for all statistical criteria was 0.05.
Results and discussion
For the period from 2011 to 2015 the trend has been toward the increase of the incidence rate of community-acquired pneumonia in the Russian Federation and Altai Krai (Figure 1). In 2015 the incidence rate in the RF was 337.8±0.5 per 100,000 population being 1.1 times higher (p=0.0001) than in 2011 (316.0±0.5 per 100,000 population). The highest incidence rate was noticed in 2013 and it was 389.9±0.5 per 100,000 population.
In 2015 the incidence rate in Altai Krai was 452.2±4.4 per 100,000 population being 3.8 times higher (p=0.0001) than in 2011 (118.6±2.2 per 100,000 population). The highest incidence rate was noticed in 2014 and it was 604.0±5 .00/0000. Starting from 2014 the growth of the incidence rate of community-acquired pneumonia was registered in Altai Krai in comparison with the Russian Federation. It is worth mentioning that in 2014 the vaccination against pneumococcal infection was included into the National Calendar of Prophylactic Immunization. That is why we can assume that the dominance of CAP in the incidence structure in AK is associated with vaccination shortage in comparison with the RF.
However, the mean long-term incidence rate of community-acquired pneumonia in the RF over the past period was 348.5±0.5 per 100,000 population being 1.1 times higher than in Altai Krai (323.0±3.7 per 100,000 population, p=0.001).
700 600 ?00 400 300
200 100
604.0
316.0
344.9
389.9
4?2,2
276.8
354.1
337.8
118.6
163.3
2011
2012
2013
2014
201?
RP
AK
Figure 1. The dynamics of the incidence rate of community-acquired pneumonia in the Russian Federation and Altai Krai during 2011-2015 (per 100,000 population)
During the studied period the mean incidence rate of CAP in the RF in the child group (0-14 years old, child incidence rate) was 687.3±1.7 per 100,000 children being 2.5 times higher than mean teenager incidence rate (15-17 years old) (271.7±2.6 per 100,000
teenagers, p=0.00001) and 2.4 times higher the incidence rate in the adult group (18 and over 18 years old) (283.2±0.5 per 100,000 adults, p=0.00001, Figure 2).
1000 800 600 400 200 0
694,2 771,8 733 9
592,8^ 644,1
■ 3?7 8 356,8
265,3 51,1 a 280,1 211 fi
222,2 i 278,3 i J 1y i 243,3 i 208,5 i
2011 2012 2013 2014 2015
— Children -Teenagers -Adults
Figure 2. The dynamics of the age structure of the incidence rate of community-acquired pneumonia in the Russian Federation during 2011-2015 (per 100,000 population of the each age group)
During the period of the highest incidence rate (in 2013) its growth rate in adults was higher than in teenagers and children. The growth of the incidence rate of CAP in adult population was 13% (from 278.3±0.5 per 100,000 adults in 2012 to 314.9±0.5 per 100,000 adults in 2013, p=0.0001). The growth of the incidence rate in children was 11% (from 694.2±1.8 per 100,000 children in 2012 to 771.8±1.8 per 100,000 children in 2013, p=0.0001), the growth of the incidence rate in teenagers was 9% (from 327.8±2.8 per 100,000 teenagers in 2012 to 356.8±3.0 per 100,000 teenagers in 2013, p=0.001). During the year when the decrease of the incidence rate was registered the rate of the decrease was low-
er in children than in teenagers and adults. In 2014 the decrease of the incidence rate in children was 5% (up to 733.9±1.80/0000 of children, p=0.0001), in adults - 11% (up to 280.1±0 .50/0000 of adults, p=0.0001), in teenagers - 32% (up to 243.3±2.5 per 100,000 teenagers, p=0.0001).
In AK the incidence rate in children was also higher than in teenagers and adults (Figure 3). The mean incidence rate in children was 1027.2±16.3 per 100,000 children being 4.2 times higher than the mean incidence rate in teenagers (245.6±19 per 100,000 teenagers, p=0.0001) and 3.7 times higher than the mean incidence rate in adults (280.9±3.8 per 100,000 adults, p=0.0001).
Figure 3. The dynamics of the age structure of the incidence rate of community-acquired pneumonia in the Altai Krai during 2011-2015 (per 100,000 population of the each age group)
During the period of the highest incidence rate (in 2014) its growth rate in children was higher than in teenagers and adults. The growth of the incidence rate in children was 704% (from 443.1±10.6 per 100,000 children in 2013 to 3561.8±29.6 per 100,000 children in 2014, p=0.00001). The growth of the incidence rate in teenagers was 114% (from 243.8±19.4 per 100,000 teenagers in 2013 to 521.3±28.5 per 100,000 teenagers in 2014, p=0.001); the growth of the incidence rate in adults was 106% (from 243.8±3.5 per 100,000 adults in 2013 to 501.8±5.1 per 100,000 adults in 2014, p=0.0001).
During the year when the decrease of the incidence rate was registered (2015) the rate of the decrease was also higher in children than in teenagers and adults. The decrease of the incidence rate in children was 78.2% (up to 774.9±13.7 per 100,000 children, p=0.0001), in adults - 22.7% (up to 387.7±4.50/0000 of adults, p=0.0001), in teenagers - 45.1% (up to 286.3±21.1 per 100,000 teenagers, p=0.001).
To sum it up, during 2011-2015 the incidence rate in children was 1.5 times higher in AK than in the RF (mean incidence rates 1027.2±16.3 and 687.3±1.7 per 100,000 children respectively, p=0.0001). The mean incidence rate of CAP in teenagers was 1.1 times higher in the RF than in AK (271.7±2.6 and 245.6±19 per 100,000 teenagers respectively, p=0.061). The mean incidence rate in adults has no significant difference (280.9±3.8 per 100,000 adults in AK and 283.2±0.5 per 100,000 adults in the RF).
The age structure of community-acquired pneumonia patients was mostly represented by adults in the Russian Federation and Altai Krai. In the RF the part of adults on average for the period was 66.3±0.1%. In Altai Krai the part of adult CAP patients was 1.2 times larger (p=0.0001): 76.6±0.1% (Figure 4, 5).
It should be mentioned that for the studied period the part of adult CAP patients in Altai Krai decreased by 12.2% (from 80.7±0.6% in 2011 to 68.5±0.4% in 2015, p=0.0001). In the RF the similar decrease is not significant: 2.6% (from 69±0.1% in 2011 to 66.4±0.1% in 2015, p=0.0001).
For the studied period the part of CAP patients in AK in the child group increased by 11.8% (from 18±0.7% in 2011 to 29.8±0.4% in 2015, p=0.0001). In the RF the part of CAP patients in the child group also insignificantly increased by 3.1% (from 28.8±0.1% in 2011 to 31.9±0.1% in 2015, p=0.0001).
The part of CAP patients in the teenager group was 2.3±0.02% in the RF and 2.6±0.05% on average. The trend has been toward the increase of the part of CAP patients in the teenager group in AK from 1.3±0.2% in 2011 to 1.7±0.1% in 2015 (p=0.061). In the RF the part of CAP patients in this group decreased from 2.2±0.02% in 2011 to 1.7±0.02% in 2015 (p=0.0001).
Summarizing the above, in 2015 the proportions of the age groups in the age structure of community-acquired pneumonia patients became quite similar in Russia and Altai Krai.
According to the Form No 2 of the State Statistical Reporting Information About Infectious and Parasitic Diseases bacterial types of community-acquired pneumonia prevailed in Altai Krai making up 67.3±0.5% of all other types of reported cases of community-acquired pneumonia during the period from 2011 to 2015 (Table 1). 1.9±0.2% of them were represented by viral types of community-acquired pneumonia. It should be noted that the number of validated diagnoses of bacterial pneumococcal community-acquired pneumonia increased every year. Thus, 3 cases of pneumococ-cal pneumonia were reported in 2011 and 39 cases - in 2015 (absolute numbers). This increase is explained by the growth of the number of laboratory tests for pneumococcus identification and the in-
traduction of the necessary test systems. However, this information does not show real numbers
of the incidence rate of pneumococcal infection in Altai Krai because of the underfunding.
100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0%
65,S 2.6 64,2 1,9
65,8
69,0 66.4
2 2 2.9 1,7
28.8 33.8 31.9
31,3 31.6
2011
2012
2013
2014
201 ?
I Children 0-14 years old H Teenagers 15-17 years old
Adults
Figure 4. The age structure of community-acquired pneumonia patients in the Russian Federation during 2011-2015 (%)
100% 90% S0% 70% 60% 50% 40% 30% 20% 10% 0%
80,7 1,3 78,1 3,3 77,9 3,4 77,9 3,4 68,5 1.7
29.8
18 18,6 18,7 18,7
2011 2012 2013 2014
■ Children (0-14 years old) M Teenagers (15-17 years old)
2015
Figure 5. The age structure of community-acquired pneumonia patients in Altai Krai during 2011-2015 (%)
Table 1
Etiological structure of community-acquired pneumonia (absolute numbers)
Types of community-acquired 2011 2012 2013 2014 2015
Bacterial 2738 3932 5296 10855 3206
with pneumococcus as a causative agent 3 1 1 25 39
Viral 129 0 5 476 114
All 2867 3932 6639 14440 10785
According to Information Source Book about the Situation with Infectious Diseases and Their Prevention in Altai Krai during 2011-2015 we can note, that the part of pneumococcus found in the phlegm during these years increased from 4.40±0.2%
in 2013 to 6.59±0.2% in 2015 (p=0.001) and the part of pneumococcus found in the blood increased from 0.01±0.01% in 2013 to 0.05±0.02% (p=0.061) in 2015 (Table 2).
Table 2
Pneumococcus found in clinical samples in Altai Krai during 2013-2015 (absolute numbers)
2013
Clinical
samples _
Result +
%
2014
Clinical samples (pcs)
Result +
%
2015
Clinical samples (pcs)
Result +
%
Phlegm
11989
528
4,40
11958
689
5,76
11178
737
6,59
Pleural fluid
4907
105
2,14
5051
92
1,82
4159
65
1,56
Ear secretion
3553
44
1,24
3114
22
0,71
3506
13
0,37
Blood
21123
0,01
19255
0,04
22207
12
0,05
CSF
1250
6
0,48
3407
0,26
1511
0
0,00
Conclusion
1. The conducted retrospective analysis of the incidence rate of community-acquired pneumonia during 2011-2015 showed that this disease is a significant problem for Altai Krai because since 2014 the incidence rate of CAP in AK was higher than the incidence rate of CAP in the RF.
2. In 2011-2015, the incidence rate of CAP in children was higher than in teenagers and in adults both in AK and in the RF. In AK it was 1.5 times higher than in the RF. The mean incidence rate of CAP in the teenager group in the RF was 1.1 times higher than in AK. The mean incidence rate of CAP in adults had no significant difference.
3. The age structure of community-acquired pneumonia patients was mostly represented by adults. The part of adult community-acquired pneumonia patients was 76.6% of all community-acquired pneumonia patients in AK being 1.2 times larger than in the RF (66.3%). For the studied period in AK the part of CAP patients in the adult group decreased by 12.2%, the part of CAP patients in the child group increased by 11.8% and the part of CAP patients in the teenager group increased by 0.4%.
4. Bacterial types of community-acquired pneumonia dominated over viral types and made up 67.7% of all CAP types for the studied period of time.
5. According to the results of laboratory tests, we noticed the percentage increase of pneumococcal CAP.
References
1. Harat R. et al. Prospective, population-based surveillance of the burden of Streptococcus pneumoniae in community-acquired pneumonia in older adults, Chrzanow County, Poland, 2010 to 2012. Pneumonologia I Alergologia Polska. 2016; 84(2):95-103.
2. Harris M, Clark J, Coote N, Fletcher P, Har-nden A, McKean M, et al. British Thoracic Society guidelines for the management of community acquired pneumonia in children: update 2011. Thorax. 2011; 66:1-23.
3. Mcintosh K. Community-acquired pneumonia in children. N Engl J Med. 2002; 346:429-37.
4. Juvén T, Mertsola J, Waris M, Leinonen M, Meurman O, Roivainen M, et al. Etiology of community-acquired pneumonia in 254 hospitalized children. Pediatr Infect Dis J. 2000; 19:293-8.
5. RudanI, O'BrienKL, NairH, LiuL, Theo-doratouE, QaziS, etal. Epidemiology and etiology of childhood pneumoniain 2010: estimates of incidence, severe morbidity, mortality, underlying risk factors and causative pathogens for 192 countries. J Glob Health. 2013; 3(1):14-4.
6. Lobzin Yu.V. et al. Serotypes of Streptococcus pneumoniae causing the main noso-logical entities of pneumococcal infections. Journal Infectology. 2013; 5(4): 36-42.
7. TatochenkoV.K. et al. 13-valent pneumococcal conjugate vaccine. Current Pediatrics". 2012; 11(2):44-47.
8. Kharit S.M., Perova A.L. Modern approaches to the prevention of pneumococcal infection. Medical Council. 2015; 16:64-67.
9. Martynova G.P. et al. Pneumococcal infection in children. Medical alphabet. Epidemiology and hygiene. 2013; 1:12-16.
Contacts:
Corresponding author - Kozyanova Yuliya Anatol-yevna, postgraduate at the Department of epidemiology, microbiology and virology of Altai State Medical University, Barnaul. 656031, Barnaul, Papanitsev Ulitsa, 126. Tel.: (3852) 256624. Email: [email protected]
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