2015 HSC Section 1 Book of Articles

The Pediatric Infectious Disease Journal •  Volume 33, Number 10, October 2014

Chronic Sinusitis

prescribed antibiotics post-surgery were cephalosporins (46%) and amoxicillin-clavulanate (17%).

TABLE 1.  Serotype Distribution of Pneumococcal Isolates Recovered From Children Undergoing Endoscopic Sinus Surgery

DISCUSSION Our study revealed important changes in the epidemiology of S. pneumoniae among children with chronic sinusitis after the introduction of PCV13 in 2010. The proportion of cases of chronic sinusitis attributable to S. pneumoniae showed a significant decline in the 3 years after the introduction of PCV13. Isolation of PCV13 serotypes from children with chronic sinusitis also decreased sig- nificantly, mostly related to a substantial decrease of serotype 19A. In our study, the overall isolation rate of S. pneumoniae was 14%. This result is similar to previous studies from Brook et al 2 and Merino et al 16 who reported a pneumococcal isolation rate of 13% among adolescents and adults with chronic sinusitis during 1987–2004 and pre-PCV7 period, respectively. However, Tinkel- man et al 4 reported a higher pneumococcal isolation rate of 23% among young children (mean age 4.9 years) with chronic sinusitis before the introduction of PCVs; this rate is similar to our results (22%) from the pre-PCV13 period, which suggests that S. pneu- moniae might play a more important role in chronic sinusitis in younger children. Despite a similar overall isolation rate of S. pneumoniae to studies conducted in the pre- and early post-PCV7 period, we demonstrated a decrease of 13% ( P < 0.0001) in the proportion of chronic sinusitis cases attributable to S. pneumoniae after the introduction of PCV13. We also found that the proportion of chronic sinusitis cases because of PCV13 serotypes decreased 31% ( P = 0.003) in the post-PCV13 period, which is consistent with the impact of PCV13 in invasive pneumococcal disease in US chil- dren. 14,17 Our findings also provide evidence of indirect protection of PCV13 given the substantial decline in chronic sinusitis attribut- able to S. pneumoniae despite an incomplete vaccination rate. A recent study reported a 50% decline in nasopharyngeal coloniza- tion by PCV13 serotypes in non-PCV13 immunized children in Massachusetts by 2012. 18 Pneumococcal serotype 19A was described as the most com- mon serotype isolated from children with invasive pneumococcal disease 13 as well as chronic sinusitis 12 after the introduction of PCV7. In our study, we demonstrated a pronounced decline of serotype 19A (38% vs. 11%; −27% P = 0.007) after the introduction of PCV13. Moreover, serotype 19A was not responsible for any of the cases of chronic sinusitis in 2013. Non-PCV13 serotypes represented 86% of all the isolates in the post-PCV13 period; and serotype 15C became the most common serotype during the same period. Similarly, Lee et al 19 evaluated rates of pneumococcal colonization in children after PCV13 introduction and reported that serotype 15B/C has emerged as the most common isolate, whereas serotype 19A remained the second most common serotype in 2011. Despite these changes in serotype distribution, we did not observe an early emergence of replacement non-PCV13 serotypes. A significantly greater number of serotype 19A isolates showed high MIC for penicillin and ceftri- axone than non-19A serotypes, as described in previous studies. 12,13 In our study, 18% of children with chronic sinusitis had S. pneumoniae -only infections; the remainder had polymicrobial infections. Similar results among patients with chronic sinusitis have been described. 10,12 Results from an AOM study in children described that S. pneumoniae -only infections were associated with serotypes identified as having higher disease potential, whereas mixed S. pneumonia e and H. influenzae infections were associ- ated with serotypes identified as having low disease potential. 20 Similarly, Xu et al 21 reported when S. pneumoniae co-colonized the nasopharynx with H. influenzae , the latter predominated over all S. pneumoniae strains except for serotype 19A to cause AOM.

Pre-PCV13 Post-PCV13 Total

P

PCV13  19A

21

4 0 1 5 6 4 2 4 3 2 0 1 2 0 1 0 1 0 0

25

0.0074

 19F

2 2 7 3 4 5 1 2 1 2 1 0 1 0 1 0 1 1

2 3

NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS

 3

Non-PCV13  35B

12

 15C

9 8 7 5 5 3 2 2 2 1 1 1 1 1 1

 6C

 23A

 11

 15B  15A  22F  23B  33F

 10  16  17  21

 33A

 34

Pre-PCV13 versus post-PCV13 periods. NS, no significant.

polymicrobial infections. An increase in the isolation of Prevotella spp. was noted in the post-PCV13 period ( P = 0.02) among patients with pneumococcal isolates. None of the patients developed intracranial complica- tions. Two patients were treated for allergic fungal sinusitis and pneumococcal (serotype 10 and 15C) sinusitis with antibiotics and steroids. One patient (serotype 23A) developed mastoiditis 3 months after completing antibiotic therapy for sinusitis. Seven patients had a second episode of pneumococcal sinusitis during the study period; all of them underwent repeat ESS and intraop- erative cultures were obtained. Data for the pneumococcal sero- type for the second episode were not available in 3 patients. None of the other 4 patients had the same pneumococcal serotype that was isolated during the first surgical procedure. The most common

TABLE 2.  Other Organisms in Addition to S. pneumoniae Isolated From Children Undergoing Endoscopic Sinus Surgery

Species

Pre-PCV13 Post-PCV13 Total

P

Nontypeable

28

19

47 NS

H. influenzae

22

11

33 NS 10 NS 7 NS 5 NS

Moraxella catarrhalis

7 6 3 0 3

3 1 2 4 1

S. aureus

Fungal species* Haemophilus Prevotella spp. Pseudomonas aureginosa parainfluenzae Coagulase-negative Staphylococcus Stenotrophomonas maltophilia Other organisms†

4 0.02 4 NS

3

0

3 NS

2

0

2 NS

5 6 NS *Two isolates each of Candida spp. and Aspergillus flavus . One isolate each of Fusobacterium spp., Bipolaris spp. and Curvularia spp. †One isolate each of Escherichia coli , Klebsiella pneumoniae , Enterobacter cloacae , Corynebacterium spp., Neisseria spp. and alpha-hemolytic Streptococcus spp. 1

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