Invasive Pneumococcal Disease Quarterly Report. July September 2017

Transcription

1 Invsive Pneumococcl Disese Qurterly Report July September 2017 Prepred s prt of Ministry of Helth contrct for scientific services by Rebekh Roos Helen Heffernn October 2017

2 Acknowledgements This report could not hve been produced without the continued support of stff in the public helth units nd dignostic microbiology lbortories throughout New Zelnd who provide us with dt from their regions nd refer isoltes to ESR. The uthors would lso like to thnk Julie Morgn (ESR Invsive Pthogens Lbortory) for providing serotyping dt nd Luke Scullion (ESR Helth Intelligence Tem) for dt checking. Disclimer This report or document ( the Report ) is given by the Institute of Environmentl Science nd Reserch Limited ( ESR ) solely for the benefit of the Ministry of Helth, Public Helth Service Providers nd other Third prty Beneficiries s defined in the Contrct between ESR nd the Ministry of Helth, nd is strictly subject to the conditions lid out in the contrct. Neither ESR nor ny of its employees mkes ny wrrnty, express or implied, or ssumes ny legl libility or responsibility for use of the Report or its contents by ny other person or orgnistion.

3 Introduction Since 17 October 2008, invsive pneumococcl disese (IPD) hs been notifible to the locl Medicl Officer of Helth under the Helth Act On 1 June 2008, pneumococcl conjugte vccine (PCV) ws dded to the New Zelnd childhood immunistion schedule. Initilly the 7-vlent conjugte vccine (PCV7), Prevenr, ws used. In July 2011, Prevenr ws replced on the schedule with the 10-vlent conjugte vccine (PCV10), Synflorix. In July 2014, Synflorix ws replced by the 13-vlent conjugte vccine (PCV13), Prevenr13. In July 2017, Prevenr13 ws replced by Synflorix. PCV10 includes the seven serotypes in PCV7 (4, 6B, 9V, 14, 18C, 19F nd 23F) s well s serotypes 1, 5 nd 7F, nd cross-rectivity to serotype 19A. PCV13 includes the 10 serotypes in PCV10 s well s serotypes 3, 6A nd 19A. The recommended schedule is four doses, given t 6 weeks, 3 months, 5 months nd 15 months of ge. These qurterly reports re prt of n enhnced surveillnce progrmme to monitor the impct of PCV vccintion, including the chnges in vccine vlency, on the epidemiology of IPD in New Zelnd. Methods The dt presented in this report (except for immunistion sttus) is bsed on the informtion recorded on EpiSurv, the ntionl notifible disese surveillnce system, s t 20 October Any chnges mde to EpiSurv dt by public helth unit stff fter this dte will not be reflected in this report. Immunistion sttus of cses tht were eligible for PCV vccintion ws extrcted from the Ntionl Immunistion Register. Denomintor dt used to determine ll disese rtes in this report ws derived from the 2015 nd 2016 mid-yer popultion estimtes published by Sttistics New Zelnd unless otherwise specified. Rtes hve not been clculted where there re fewer thn five notified cses in ny ctegory. The Fisher s exct test ws used to determine sttisticl significnce. Results re considered sttisticlly significnt when the P vlue is Streptococcus pneumonie isoltes re serotyped t ESR by the cpsulr ntigen rection (Neufeld test) using the Dnish system of nomenclture nd ser obtined from the Sttens Serum Institut. Methods hve not been estblished t ESR to identify the strin type when only pneumococcl DNA, rther thn n isolte, is vilble. Therefore, the serotype cn only be determined for culture-positive IPD cses. Serotype dt for invsive isoltes of S. pneumonie ws mtched with the relevnt IPD cse notifiction. Cse definition A cse of invsive pneumococcl disese is defined s: the isoltion of S. pneumonie from CSF, blood or other normlly sterile site; or the detection by nucleic cid mplifiction test of pneumococcl DNA in CSF, blood or other normlly sterile site; or positive newer-genertion S. pneumonie ntigen test on CSF or pleurl fluid. 1 1 A positive S. pneumonie ntigen test on pleurl fluid ws dded to the cse definition in mid-september Invsive Pneumococcl Disese Qurterly Report, July September

4 Number of notifictions Results There were 209 IPD cses notified in the July September 2017 qurter, compred with 182 cses in the sme qurter in IPD displys distinct sesonl pttern with winter pek nd summer trough (Figure 1). The notifiction rte for the ltest 12-month period ending September 2017 (11.3 per 100,000 popultion, 530 cses) ws higher thn the rte for the previous 12-month period ending September 2016 (10.6 per 100,000, 488 cses). Figure 1. Number of cses of invsive pneumococcl disese by qurter reported, Jnury 2010 September Yer (Qurter) The distribution of IPD cses nd rtes by ge group is presented in Tble 1. During the ltest 12-month period, the highest rte ws in the 65 yers ge group (33.2 per 100,000 popultion, 232 cses). Compring the ltest 12-month period with the previous 12-month period, there were no significnt chnges in the ge-specific rtes. Tble 1. Number of cses nd rtes of invsive pneumococcl disese by ge group Age group Jul-Sep months ending Sep months ending Sep 2016 Cses Cses Rte Cses Rte <2 yers yers yers yers Totl Rte is expressed s cses per 100,000 popultion. Invsive Pneumococcl Disese Qurterly Report, July September

5 The distribution of IPD cses nd rtes by region is presented in Tble 2. The highest rtes for the ltest 12-month period were in the Northern nd Midlnd regions (11.8 per 100,000 popultion, 212 cses nd 13.8 per 100,000 popultion, 124 cses, respectively). Compring the ltest 12-month period with the previous 12-month period, there were no significnt chnges in ny region or DHB. Tble 2. Number of cses nd rtes of invsive pneumococcl disese by region Region Jul-Sep months ending Sep months ending Sep 2016 Cses Cses Rte Cses Rte Northern b Midlnd c Centrl d Southern e Totl Rte is expressed s cses per 100,000 popultion. b Includes Northlnd, Witemt, Aucklnd nd Counties Mnuku DHBs. c Includes Wikto, Lkes, By of Plenty, Tirwhiti nd Trnki DHBs. d Includes Hwke s By, Whngnui, MidCentrl, Hutt Vlley, Cpitl & Cost, Wirrp nd Nelson Mrlborough DHBs. e Includes West Cost, Cnterbury, South Cnterbury nd Southern DHBs. A culture ws received t ESR for serotyping from 195 (93.3%) of the 209 cses notified in the July September 2017 qurter. Tble 3 shows the number of IPD cses due to ech of the serotypes included in PCV7, PCV10 nd PCV13, nd due to non- PCV13 serotypes. The number of IPD cses due to PCV13 serotypes decresed 8.2% between the lst two 12-month periods (195 to 179 cses). In contrst, the number of IPD cses due to non-pcv13 serotypes incresed 18.3% between the lst two 12-month periods (268 to 317 cses). The increse in IPD due to non-pcv13 types occurred in the <2 yers nd 5 yers ge group (Tble 3). The three most prevlent serotypes during the lst 12 months were 19A, 8 nd 22F. However between the lst two 12-month periods, totl cses of IPD due to type 19A decresed, wheres cses of the two non-pcv13 types, 8 nd 22F, incresed (Tble 3). Invsive Pneumococcl Disese Qurterly Report, July September

6 Tble 3. Number of invsive pneumococcl disese cses by serotype nd ge group Age group <2 yers 2 4 yers 5 yers Totl Serotypes Q b 2016 c Q b 2016 c Q b 2016 c Q b 2016 c B V C F F Totl PCV F Totl PCV A A d Totl PCV C N A A F A B C F F F A B F B F Other types e Totl non- PCV Cses reported in the third qurter of 2017 (July-September 2017). b Cses reported in the 12 months ending 30 September c Cses reported in the 12 months ending 30 September d The indictions for PCV10 include cross-protection ginst 19A disese. e Any of these other types ccounted for <5 IPD cses during the 12 months ending 30 September Invsive Pneumococcl Disese Qurterly Report, July September

7 Tble 4 shows the immunistion sttus for cses notified in the July September 2017 qurter who were ge-eligible for PCV (ie, cses born fter 1 Jnury 2008 nd ged 6 weeks). Immunistion sttus ws bsed on informtion recorded in the Ntionl Immunistion Register. Of the 22 cses tht were ge-eligible for PCV, two did not hve records in the NIR nd nother two were recorded s not hving received ny doses of PCV (due to prentl decline). Of the remining 18 cses, one cse ws due to serotype 14, one cse ws due to serotype 19A, 10 cses were due to non-pcv13 serotypes, nd serotype informtion ws not vilble for six cses. The serotype 14 cse ws recorded s hving 4 doses of PCV13 (lthough 3 of these were given overses) this cse is presumed vccine filure. The serotype 19A cse hd received two doses of PCV7 nd two doses of PCV10 nd is lso considered vccine filure. Ethnicity ws recorded for 194 (92.8%) of the 209 IPD cses notified in the July September 2017 qurter (Tble 5). The ge-stndrdised rtes of IPD were highest for the Pcific peoples (67.5 per 100,000 popultion, 24 cses) nd Māori (48.9 per 100,000, 50 cses) ethnic groups. The rtes for these two ethnic groups were, respectively, 5.5 nd 4.0 times higher thn the rte for the Europen or Other ethnic group (12.3 per 100,000, 112 cses) (Tble 5). In the July September 2017 qurter, 199 (95.2%) of the 209 IPD cses hd residentil ddress recorded tht could be ssigned 2013 New Zelnd Deprivtion Index (NZDep13) score (Tble 6). The most deprived res (NZDep13 quintile 5) hd the highest rte of IPD (34.6 per 100,000 popultion, 72 cses), 2.4 times the rte in the lest deprived res (14.2 per 100,000, 31 cses). Rtes of IPD by deprivtion index could only be clculted for ll ges combined becuse popultion dt by NZDep13 quintile nd ge groups ws not vilble. Invsive Pneumococcl Disese Qurterly Report, July September

8 Tble 4. Immunistion sttus of the invsive pneumococcl disese cses notified in the July-September 2017 qurter nd who were eligible for PCV Number of doses received Cses due to PCV7 serotypes: 4, 6B, 9V, 14, 18C, 19F or 23F b Cses due to dditionl PCV10 serotypes: 1, 5, 7F b Cses due to dditionl PCV13 serotypes: 3, 6A, 19A b Cses due to non- PCV13 serotypes b Totl b,c Number Number Number Number Number e d 0 1 f 6 13 Totl Number of doses received prior to 14 dys before onset of IPD. Onset of IPD ws determined using the erliest episode dte vilble from onset of illness dte, hospitlised dte or dte reported to the public helth unit. b Only IPD cses eligible for PCV s prt of the childhood immunistion schedule (ie, cses born fter 1 Jnury 2008 nd ged 6 weeks) re presented. c The totl number of cses includes six cses where serotype informtion ws not vilble. d Cse due to serotype 14. e Cse due to serotype 19A. f Cse due to serotype 19A. Note: Immunistion sttus ws unknown for two cses who were eligible for PCV (not included in tble). Invsive Pneumococcl Disese Qurterly Report, July September

9 Tble 5. Number of cses, nd ge-specific nd ge-stndrdised rte per 100,000 popultion of invsive pneumococcl disese by ethnic group nd ge group, July September 2017 qurter Age group (yers) Māori Pcific peoples Asin MELAA Europen or Other Cses Rte b Cses Rte b Cses Rte b Cses Rte b Cses Rte b < Totl cses nd crude rte for ll ges c Age-stndrdised rte d Middle Estern/Ltin Americn/Africn. b Annulised rte per 100,000 popultion. c Ethnicity ws recorded for 194 (92.8%) of cses in the July-September 2017 qurter. d The ge-stndrdised rtes re direct-stndrdised to the ge distribution of the totl New Zelnd popultion. Note: Denomintor dt used to determine disese rtes for ethnic groups is bsed on the proportion of people in ech ethnic group from the usully resident 2013 census popultion pplied to the 2016 mid-yer popultion estimtes from Sttistics New Zelnd. Ethnicity is prioritised in the following order: Māori, Pcific peoples, Asin, MELAA nd Europen or Other ethnicity (including New Zelnder). Where there were fewer thn five cses in ny ctegory, rte hs not been clculted. Invsive Pneumococcl Disese Qurterly Report, July September

10 Tble 6. Number nd percentge of invsive pneumococcl disese cses by quintiles of the 2013 New Zelnd deprivtion index nd ge group, July September 2017 qurter NZDep13 quintile <2 yers 2-4 yers 5-64 yers 65 yers Totl Cses % b Cses % b Cses % b Cses % b Cses % b Rte c Totl d Quintile of the 2013 New Zelnd Deprivtion Index (1 = lest deprived nd 5 = most deprived). b Percentge of cses within the ge group in the quintile. c Annulised rte per 100, 000 popultion, bsed on the 2013 census dt from Sttistics New Zelnd. d Accurte New Zelnd Deprivtion Index (NZDep13) dt ws vilble for 199 (95.2%) cses notified in the July-September 2017 qurter. Invsive Pneumococcl Disese Qurterly Report, July September