2015 HSC Section 1 Book of Articles

Olarte et al

The Pediatric Infectious Disease Journal •

Volume 33, Number 10, October 2014

www.pidj.com

Denmark; Daco, Inc, Carpinteria, CA) in the Infectious Disease

Research Laboratory.

Antimicrobial susceptibility testing for penicillin and ceftri-

axone was performed by standard microbroth dilution with Muel-

ler-Hinton media supplemented with 3% lysed horse blood in the

Infectious Disease Research Laboratory. Susceptibilities for eryth-

romycin, clindamycin and trimethoprim-sulfamethoxazole were

determined by standard disk diffusion testing in the TCH Clinical

Microbiology Laboratory. Susceptibility categories were “suscepti-

ble,” “intermediate” or “resistant” as defined by the 2012 Clinical

and Laboratory Standards Institute.

Demographic and clinical information was collected retro-

spectively and recorded on a case report form. Administration of

PCV7 or PCV13 was documented through the medical records or

by contacting the patient’s healthcare provider.

We defined the prevaccine period as August 2008 through

December 2010 (29 months). We defined the postvaccine period

as January 2011 through December 2013 (36 months). PCV13 was

licensed in the United States in February 2010, overlapping the

endmost part of the prevaccine period; however, patients included

in the prevaccine period had not received any PCV13 doses.

To estimate the proportion of chronic sinusitis cases attrib-

utable to

S. pneumoniae,

we used ICD-9 (

International Classifica-

tion of Diseases, 9th Revision

) codes to identify the total number

of patients with chronic sinusitis (ICD-9 code 473) who under-

went ESS (ICD-9 code 31231 or 31000) during the study period.

Descriptive statistics were used to characterize the study popula-

tion. The

test and Fisher’s exact test were used to compare the

characteristics of patients with chronic sinusitis before and after

introduction of PCV13. IBM SPSS statistics V22.0.0 was the statis-

tical program used.

≤

0.05 was considered significant.

RESULTS

During the study period, 652 patients (245 in the pre-PCV13

period and 407 in the post-PCV13 period) with chronic sinusitis

who underwent ESS were identified based on ICD-9 codes. Of

these, 91 of 652 (14%) had a positive sinus culture for

S. pneumo-

niae

; 55 of 245 (22%) and 36 of 407 (9%) were identified in the

pre- and post-PCV13 periods, respectively (

< 0.0001). The total

number of annual pneumococcal sinusitis cases was: 19 in 2009; 26

in 2010; 11 in 2011; 20 in 2012 and only 5 in 2013.

The median age of the patients was 24 months (range: 5

months to 17 years). Sixty-one (67%) patients were male. No differ-

ences were noted in the age distribution and gender of the patients

in the pre and postvaccine periods. Fifty-nine (65%) patients were

white. All the patients presented with chronic nasal congestion/

drainage and chronic cough. Information regarding antibiotic ther-

apy before surgery was only available in 43 patients (47%); of those

40 had received an antibiotic in the 4 weeks before surgery.

The most common comorbid conditions were chronic oti-

tis media (67%), allergic rhinitis (37%), reactive airway disease/

asthma (30%) and gastroesophageal reflux (15%). Of 91 patients,

23 (25%) had a significant underlying condition: 5 patients with

cardiovascular disorder, 3 with central nervous system disorder, 3

with cystic fibrosis, 2 with Trisomy 21, 2 with malignancy, 2 with

renal disorders and 1 each with Kartagener syndrome, Cri-du-chat,

status post lung transplant secondary to bronchiolitis obliterans,

Turner syndrome, juvenile osteochondrosis or thalassemia trait.

No statistical difference in the type or frequency of comorbid or

underlying medical conditions was observed between the pre- and

post-PCV13 periods.

Eleven (12%) patients had not received any doses of pneu-

mococcal vaccine. Eighty (88%) patients received at least 1 dose

of pneumococcal vaccine; of those 30 patients received at least 1

dose of PCV13. Seventy-two (79%) patients received 3 or more

doses of pneumococcal vaccine; of those 14 patients received 3 or

more doses of PCV13. No statistical difference was observed in

the pneumococcal immunization status of the patients between the

pre- and post-PCV13 periods. All 91 pneumococcal isolates were

serotyped. Nineteen different serotypes were identified.

Thirty isolates (33%) were PCV13 serotypes and 61 (67%)

isolates were non-PCV13 serotypes. The percentage of PCV13 cases

decreased 31% in the post-PCV13 era (

= 0.003) when compared

with the pre-PCV13 era (Fig. 1). This decrease was driven by a

reduction of 27% of serotype 19A cases in the post-PCV13 period (

= 0.007). No serotype 19A cases were identified in 2013. Serotype

19A (38%) and serotype 15C (17%) were the most common sero-

types in the pre- and post-PCV13 periods, respectively (Table 1). All

the cases in 2013 were because of non-PCV13 serotypes.

Five patients developed sinusitis because of PCV13 sero-

types (serotype 19A in 4 patients and serotype 3 in 1 patient)

despite being fully immunized for

S. pneumoniae

by age includ-

ing at least 1 PCV13 dose. Of these patients, 2 had an underlying

condition: 1 patient had Trisomy 21 and Lennox-Gastaut syndrome

and the other had asthma.

All of the pneumococcal isolates were tested for antimi-

crobial susceptibility. The percentages of isolates with penicillin

minimal inhibitory concentration (MIC)

≥

g/mL and ceftriaxone

MIC

≥

g/mLwere similar in the pre- and post-PCV13 periods. Sero-

type 19A accounted for all the isolates with penicillin MIC

≥

g/mL

and ceftriaxone MIC

≥

g/mL. Isolates with a penicillin

MIC

≥

g/mL and ceftriaxone MIC

≥

g/mL were more com-

monly associated with serotype 19A (

< 0.001 for both). Clindamy-

cin and trimethoprim-sulfamethoxazole nonsusceptibility also was

seen more commonly in serotype 19A isolates (

< 0.01 for both).

Sixteen cases (18%) were positive for

S. pneumoniae

only and 75 cases (82%) represented polymicrobial infections.

pneumoniae

-only infections were not associated with any particu-

lar pneumococcal serotype. The most common co-isolated organ-

isms were nontypeable

H. influenzae

(52%),

Moraxella catarrhalis

(36%) and

Staphylococcus aureus

(11%; Table 2). Of the nontypea-

ble

H. influenzae

isolates, 10 of 47 were

-lactamase positive.All

catarrhalis

isolates were

-lactamase positive with the exception of

one. Three methicillin-resistant

S. aureus

isolates were identified.

No specific age group was more affected by

S. pneumoniae

-only or

FIGURE 1.

Serotype distribution of pneumococcal

isolates recovered from children undergoing endoscopic

sinus surgery 2009–2013. PCV7-serotypes included in

the 7-valent PCV; PCV13-serotypes included only in the

13-valent PCV; non-PCV13-serotypes not included in the

13-valent PCV.

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