National Laboratory Surveillance of Invasive Streptococcal Disease in Canada - Annual Summary 2017

Executive Summary

• Streptococcus pneumoniae: 3,006 isolates causing invasive pneumococcal disease (IPD) were characterized in 2017.
• In 2017, incidence of IPD declined in children under <1 year of age to 14.9 cases per 100,000 population; and in seniors ≥60 years increased to 21.1 cases per 100,000 population. The overall crude incidence rate has remained stable averaging 9.4 cases per 100,000 population since 2009.
• PCV7 serotypes remained relatively unchanged overall in 2017 accounting for 12% of IPD. Increases were seen in serotypes 4 and 19F.
• PCV13 (not including PCV7) serotypes accounted for 18% of overall IPD, continuing an overall decline from 36% in 2012. However, rates of serotype 3 remain fairly consistent in all age groups. Continued declines of PCV7 and PCV13 serotypes in seniors ≥65 years of age, as well as lower case rates in this age group, indicate indirect reduction of disease most likely through herd immunity effects. 
• Overall levels of PPV23 and non-vaccine serotypes (NVT) have remained relatively unchanged in 2017 at 42% and 29%, respectively. Increases were seen in serotype 9N in ≥50 year olds.
• Predominant serotypes in 2017 were serotype 3 (10%), 22F (9%), 4 (8%), 9N (7%) and 8 (5%). 33F was the most prevalent serotype in <2 year olds accounting for 16% followed closely by 15B/C at 15%. For 2–4 year olds 22F remains predominant with 12%. An increase of serotype 4 in adults was associated with Western regions; 23B was predominant in 2–14 year olds, and 15A was associated with the < 65 year old age group in 2017 (Figure A).
• Antimicrobial susceptibility: Testing of 1,129 isolates indicated levels of resistance were again relatively stable during 2017 with the following resistance rates: clarithromycin (26%), penicillin (15%), doxycycline (11%), clindamycin (8%), trimethoprim/sulfamethoxazole (7%), meropenem (1.6%), and imipenem (0.1%). Serotypes 6A/C, 19A/F, 23A/F, 15A, 9V, 14 and 35B generally had the highest rates of antimicrobial resistance. Multi-drug resistance increased from 6% in 2016 to 10% in 2017. The highest rates of multi-drug resistance were seen in serotypes 15A (65%) and 19F (31%) (Figure B).
• S. pyogenes (Group A Streptococcus): 2,473 isolates causing invasive disease were characterized for emm type.
• Overall incidence of invasive disease has increased from 4.0 to 6.7 cases per 100,000 population from 2009 to 2017.
• Despite a decline since 2013, emm1 continues to be most predominant among all combined age groups and regions (18%) (Figure C). Regional increases of emm12 in the East (15%), emm74 in Central (14%) and emm49 (5%) in the West have been noted.
• Antimicrobial susceptibility: Antimicrobial resistance of S. pyogenes is relatively low, however small increases were seen in 2017 with chloramphenicol non-susceptibility at 5%, erythromycin resistance at 10%; and clindamycin resistance at 7%.
• S. agalactiae (Group B Streptococcus): There were 229 invasive Group B Streptococcus submitted to NML during 2017, of which 7 isolates were from early onset cases (infants ≤7 days old) and 8 were from late onset cases (infants 8 – 31 days old). Annual incidence of invasive disease per 100,000 population has fluctuated from a low in 2009 (27.6) to a high in 2014 (38.7), the incidence rate in 2017 was 30.6.
• Serotypes Ia (22%), IV (19%) and III and V (17% each) were most predominant.
• Antimicrobial susceptibility: Resistance to erythromycin increased to 58% while clindamycin resistance increased to 45%.

Figure A - Text Description

Bar graph displaying the percentage of Streptococcus pneumonia serotypes from 2013 to 2017 based on the total number of isolates tested annually.

Column1	2013 (n=2568)	2014 (n=2466)	2015 (n=2593)	2016 (n=2764)	2017 (n=3006)
4Footnote * (42,57,103,182,229) Footnote ‡	1.6%	2.3%	4.0%	6.6%	7.6%
6BFootnote * (15,6,10,20,8)	0.6%	0.2%	0.4%	0.7%	0.3%
9VFootnote * (9,9,7,5,12)	0.4%	0.4%	0.3%	0.2%	0.4%
14Footnote * (15,10,12,14,23)	0.6%	0.4%	0.5%	0.5%	0.8%
18CFootnote * (10,5,6,8,6)	0.4%	0.2%	0.2%	0.3%	0.2%
19FFootnote * (27,23,42,43,73)	1.1%	0.9%	1.6%	1.6%	2.4%
23FFootnote * (10,10,9,4,2)	0.4%	0.4%	0.3%	0.1%	0.1%
1Footnote ** (10,3,4,3,0)	0.4%	0.1%	0.2%	0.1%	0.0%
3Footnote ** (229,219,235,261,289)	8.9%	8.9%	9.1%	9.4%	9.6%
5Footnote ** (5,0,2,0,0)	0.2%	0.0%	0.1%	0.0%	0.0%
6AFootnote ** (15,16,9,19,6)	0.6%	0.6%	0.3%	0.7%	0.2%
7FFootnote ** (226,184,145,109,111)	8.8%	7.5%	5.6%	3.9%	3.7%
19AFootnote ** (299,220,212,176,143)	11.6%	8.9%	8.2%	6.4%	4.8%
2Footnote ^ (1,0,0,0,0)	0.0%	0.0%	0.0%	0.0%	0.0%
8Footnote ^ (119,99,137,148,151)	4.6%	4.0%	5.3%	5.4%	5.0%
9NFootnote ^ (113,109,115,138,203)	4.4%	4.4%	4.4%	5.0%	6.8%
10AFootnote ^ (47,49,45,48,57)	1.8%	2.0%	1.7%	1.7%	1.9%
11AFootnote ^ (92,99,88,91,90)	3.6%	4.0%	3.4%	3.3%	3.0%
12FFootnote ^ (90,88,126,102,123)	3.5%	3.6%	4.9%	3.7%	4.1%
15B/CFootnote ^(87,85,87,125,114)	3.4%	3.4%	3.4%	4.5%	3.8%
17FFootnote ^ (18,31,17,23,28)	0.7%	1.3%	0.7%	0.8%	0.9%
20Footnote ^ (50,69,88,81,113)	1.9%	2.8%	3.4%	2.9%	3.8%
22FFootnote ^ (312,281,252,254,267)	12.1%	11.4%	9.7%	9.2%	8.9%
33FFootnote ^ (72,56,74,98,100)	2.8%	2.3%	2.9%	3.5%	3.3%
6C (92,91,74,73,60)	3.6%	3.7%	2.9%	2.6%	2.0%
6D (3,2,3,0,0)	0.1%	0.1%	0.1%	0.0%	0.0%
7A (0,0,1,0,0)	0.0%	0.0%	0.0%	0.0%	0.0%
7B (0,1,2,0,2)	0.0%	0.0%	0.1%	0.0%	0.1%
7C (12,13,26,42,22)	0.5%	0.5%	1.0%	1.5%	0.7%
9A (1,0,2,0,0)	0.0%	0.0%	0.1%	0.0%	0.0%
9L (0,0,0,2,2)	0.0%	0.0%	0.0%	0.1%	0.1%
10B (1,4,2,2,2)	0.0%	0.2%	0.1%	0.1%	0.1%
10F (1,1,0,2,3)	0.0%	0.0%	0.0%	0.1%	0.1%
11B (1,1,4,3,0)	0.0%	0.0%	0.2%	0.1%	0.0%
11D (0,0,0,0,3)	0.0%	0.0%	0.0%	0.0%	0.1%
11F (1,0,0,0,0)	0.0%	0.0%	0.0%	0.0%	0.0%
12B (0,0,0,0,1)	0.0%	0.0%	0.0%	0.0%	0.0%
13 (4,13,7,8,6)	0.2%	0.5%	0.3%	0.3%	0.2%
15A (99,113,119,123,145)	3.9%	4.6%	4.6%	4.5%	4.8%
16F (60,72,64,72,72)	2.3%	2.9%	2.5%	2.6%	2.4%
17A (0,0,1,0,0)	0.0%	0.0%	0.0%	0.0%	0.0%
18A (2,1,0,1,0)	0.1%	0.0%	0.0%	0.0%	0.0%
18B (1,0,0,0,0)	0.0%	0.0%	0.0%	0.0%	0.0%
18F (0,0,0,1,0)	0.0%	0.0%	0.0%	0.0%	0.0%
21 (11,7,9,11,16)	0.4%	0.3%	0.3%	0.4%	0.5%
22A (1,4,1,0,1)	0.0%	0.2%	0.0%	0.0%	0.0%
23A (88,107,110,106,140)	3.4%	4.3%	4.2%	3.8%	4.7%
23B (50,86,78,83,93)	1.9%	3.5%	3.0%	3.0%	3.1%
24 (0,0,2,1,0)	0.0%	0.0%	0.1%	0.0%	0.0%
24A (0,0,0,1,0)	0.0%	0.0%	0.0%	0.0%	0.0%
24B (1,0,1,1,1)	0.0%	0.0%	0.0%	0.0%	0.0%
24F (4,12,18,21,24)	0.2%	0.5%	0.7%	0.8%	0.8%
25F (0,1,0,0,0)	0.0%	0.0%	0.0%	0.0%	0.0%
28A (4,2,2,5,10)	0.2%	0.1%	0.1%	0.2%	0.3%
29 (4,13,9,8,4)	0.2%	0.5%	0.3%	0.3%	0.1%
31 (32,39,31,46,43)	1.2%	1.6%	1.2%	1.7%	1.4%
32A (0,0,0,0,1)	0.0%	0.0%	0.0%	0.0%	0.0%
33A (10,3,10,4,2)	0.4%	0.1%	0.4%	0.1%	0.1%
33B (1,0,0,1,0)	0.0%	0.0%	0.0%	0.0%	0.0%
33C (0,0,0,0,1)	0.0%	0.0%	0.0%	0.0%	0.0%
34 (19,21,25,23,27)	0.7%	0.9%	1.0%	0.8%	0.9%
35A (3,2,1,4,2)	0.1%	0.1%	0.0%	0.1%	0.1%
35B (58,45,60,61,73)	2.3%	1.8%	2.3%	2.2%	2.4%
35C (1,1,1,0,0)	0.0%	0.0%	0.0%	0.0%	0.0%
35F (44,52,61,54,50)	1.7%	2.1%	2.4%	2.0%	1.7%
37 (4,2,2,2,2)	0.2%	0.1%	0.1%	0.1%	0.1%
38 (36,21,37,46,46)	1.4%	0.9%	1.4%	1.7%	1.5%
42 (0,0,0,0,1)	0.0%	0.0%	0.0%	0.0%	0.0%
NT (6,8,5,5,3)	0.2%	0.3%	0.2%	0.2%	0.1%
Footnote * Component of PCV7 Return to footnote * referrer Footnote ** Component of PCV13 Return to footnote ** referrer Footnote ^ Component of PPV23 Return to footnote ^ referrer Footnote ‡ Number of isolates from 2013, 2014, 2015, 2016 and 2017, respectively. Return to footnote ‡ referrer

Figure B - Text Description

A combination line and stacked bar graph displaying multidrug drug resistance trends from 2013 to 2017 for S pneumoniae.

Category 1	Resistant to 7 classesnote de bas de page *	Resistant to 6 classes	Resistant to 5 classes	Resistant to 4 classes	Resistant to 3 classes	Resistant to 2 classes	Resistant to 1 class	Resistant to ≥3 classes
2013 (n=1058)	0.1%	0.0%	2.8%	1.6%	3.0%	4.8%	20.6%	7.6%
2014 (n=1116)	0.0%	0.5%	1.0%	1.5%	2.0%	8.3%	18.3%	5.0%
2015 (n=1128)	0.0%	0.0%	1.8%	2.6%	2.4%	5.2%	18.4%	6.7%
2016 (n=1114)	0.0%	0.1%	0.8%	2.8%	2.5%	6.4%	18.2%	6.2%
2017 (n=1129)	0.0%	0.4%	1.5%	4.6%	3.1%	6.1%	19.5%	9.6%
Footnote * Antimicrobial classes include: β-lactams (amoxicillin/clavulanic acid, penicillin using meninigitis breakpoints, ceftriaxone using meningitis breakpoints, cefuroxime using parenteral breakpoint, ertapenem, imipenem and meropenem); macrolides (clarithromycin); fluoroquinolones (levofloxacin and moxifloxacin); tetracyclines (doxycycline); folate pathway inhibitors (trimethoprim-sulfamethoxazole); phenicols (chloramphenicol); lincosamides (clindamycin); oxazolidinones (linezolid). Return to footnote * referrer

Figure C - Text Description

Bar graph displaying emm types of S. pyogenes from 2013 to 2017 by percentage based on the total number of isolates tested annually.

Column1	2013 (n=1527)	2014 (n=1704)	2015 (n=1760)	2016 (n=2154)	2017 (n=2473)
1 (352,456,317,323,449)note de bas de page †	23.1%	26.8%	18.0%	15.0%	18.2%
2 (35,46,39,31,33)	2.3%	2.7%	2.2%	1.4%	1.3%
3 (36,37,150,132,61)	2.4%	2.2%	8.5%	6.1%	2.5%
4 (86,99,86,98,86)	5.6%	5.8%	4.9%	4.5%	3.5%
5 (6,9,8,11,7)	0.4%	0.5%	0.5%	0.5%	0.3%
6 (55,80,41,57,48)	3.6%	4.7%	2.3%	2.6%	1.9%
9 (14,10,11,11,41)	0.9%	0.6%	0.6%	0.5%	1.7%
11 (65,55,85,64,68)	4.3%	3.2%	4.8%	3.0%	2.7%
12 (73,108,128,137,147)	4.8%	6.3%	7.3%	6.4%	5.9%
18 (0,0,0,5,4)	0.0%	0.0%	0.0%	0.2%	0.2%
22 (22,18,26,25,25)	1.4%	1.1%	1.5%	1.2%	1.0%
28 (94,107,92,97,126)	6.2%	6.3%	5.2%	4.5%	5.1%
29 (1,8,0,2,4)	0.1%	0.5%	0.0%	0.1%	0.2%
41 (18,36,44,37,55)	1.2%	2.1%	2.5%	1.7%	2.2%
44 (4,6,3,4,4)	0.3%	0.4%	0.2%	0.2%	0.2%
48 (0,1,3,5,4)	0.0%	0.1%	0.2%	0.2%	0.2%
49 (4,1,3,12,70)	0.3%	0.1%	0.2%	0.6%	2.8%
53 (49,45,57,26,37)	3.2%	2.6%	3.2%	1.2%	1.5%
58 (4,3,9,22,14)	0.3%	0.2%	0.5%	1.0%	0.6%
59 (37,31,24,49,57)	2.4%	1.8%	1.4%	2.3%	2.3%
63 (0,1,0,1,2)	0.0%	0.1%	0.0%	0.0%	0.1%
68 (55,43,31,40,25)	3.6%	2.5%	1.8%	1.9%	1.0%
73 (3,10,9,8,15)	0.2%	0.6%	0.5%	0.4%	0.6%
74 (2,0,9,172,234)	0.1%	0.0%	0.5%	8.0%	9.5%
75 (14,21,23,33,41)	0.9%	1.2%	1.3%	1.5%	1.7%
76 (6,10,9,8,73)	0.4%	0.6%	0.5%	0.4%	3.0%
77 (36,18,36,36,33)	2.4%	1.1%	2.0%	1.7%	1.3%
80 (33,33,26,22,9)	2.2%	1.9%	1.5%	1.0%	0.4%
81 (17,30,113,160,226)	1.1%	1.8%	6.4%	7.4%	9.1%
82 (43,23,60,104,63)	2.8%	1.3%	3.4%	4.8%	2.5%
83 (34,19,24,32,37)	2.2%	1.1%	1.4%	1.5%	1.5%
87 (36,37,29,37,29)	2.4%	2.2%	1.6%	1.7%	1.2%
89 (136,159,112,107,136)	8.9%	9.3%	6.4%	5.0%	5.5%
90 (2,1,2,0,2)	0.1%	0.1%	0.1%	0.0%	0.1%
91 (19,15,25,38,34)	1.2%	0.9%	1.4%	1.8%	1.4%
92 (8,4,2,3,14)	0.5%	0.2%	0.1%	0.1%	0.6%
93 (0,1,1,3,4)	0.0%	0.1%	0.1%	0.1%	0.2%
94 (3,4,4,7,5)	0.2%	0.2%	0.2%	0.3%	0.2%
101 (28,52,42,110,87)	1.8%	3.1%	2.4%	5.1%	3.5%
102 (3,1,7,5,8)	0.2%	0.1%	0.4%	0.2%	0.3%
104 (0,1,0,1,2)	0.0%	0.1%	0.0%	0.0%	0.1%
106 (0,0,0,0,2)	0.0%	0.0%	0.0%	0.0%	0.1%
112 (0,0,2,0,2)	0.0%	0.0%	0.1%	0.0%	0.1%
114 (13,11,14,17,8)	0.9%	0.6%	0.8%	0.8%	0.3%
115 (13,3,5,6,2)	0.9%	0.2%	0.3%	0.3%	0.1%
118 (35,25,23,29,8)	2.3%	1.5%	1.3%	1.3%	0.3%
128 (0,1,0,2,3)	0.0%	0.1%	0.0%	0.1%	0.1%
162 (0,0,0,0,2)	0.0%	0.0%	0.0%	0.0%	0.1%
169 (2,1,1,2,9)	0.1%	0.1%	0.1%	0.1%	0.4%
232 (0,0,0,0,2)	0.0%	0.0%	0.0%	0.0%	0.1%
Other (31,24,25,23,16)	2.0%	1.4%	1.4%	1.1%	0.6%
Footnote † Number of isolates from 2013, 2014, 2015, 2016 and 2017, respectively. Return to footnote † referrer