Invasive Pneumococcal Disease Quarterly Report. January March 2017

Transcription

1 Invsive Pneumococcl Disese Qurterly Report Jnury Mrch 2017 Prepred s prt of Ministry of Helth contrct for scientific services by Ali Bormn Helen Heffernn My 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 Rebekh Roos 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. 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 (including immunistion sttus) is bsed on the informtion recorded on EpiSurv, the ntionl notifible disese surveillnce system, s t 8 April Any chnges mde to EpiSurv dt by public helth unit stff fter this dte will not be reflected in this report. 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, Jnury Mrch

4 Number of notifictions Results There were 76 IPD cses notified in the Jnury Mrch 2017 qurter, compred with 60 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 Mrch 2017 (10.5 per 100,000 popultion, 493 cses) ws higher thn the rte for the previous 12-month period ending Mrch 2016 (9.7 per 100,000, 446 cses). Figure 1. Number of cses of invsive pneumococcl disese by qurter reported, Jnury 2010 Mrch 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 (28.6 per 100,000 popultion, 200 cses). Compring the ltest 12-month period with the previous 12-month period, there ws significnt increse in IPD cses in the <2 yers ge group (12 to 26 cses). Tble 1. Number of cses nd rtes of invsive pneumococcl disese by ge group Age group Jn-Mr months ending Mr months ending Mr 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, Jnury Mrch

5 The distribution of IPD cses nd rtes by region is presented in Tble 2. There ws significnt increse in the rte in the Northern region in the ltest 12-month period compred with the previous 12-month period (9.7 to 12.6 per 100,000 popultion). At the DHB level, there ws significnt increse in the ltest 12-month period in Witemt DHB (5.7 to 10.0 per 100,000). Tble 2. Number of cses nd rtes of invsive pneumococcl disese by region Region Jn-Mr months ending Mr months ending Mr 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 71 (93.4%) of the 76 cses notified in the Jnury Mrch 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 9.7% between the lst two 12-month periods (207 to 187 cses). In contrst, the number of IPD cses due to non-pcv13 serotypes incresed 26.0% between the lst two 12-month periods (223 to 281 cses). The increses in IPD due to non-pcv13 types occurred mostly in the 5 yers ge group (Tble 3). The four most prevlent serotypes during the lst 12 months were 19A, 22F, 7F nd 8. Between the lst two 12-month periods there ws little chnge in the totl number of cses due to types 19A, 22F or 7F, wheres the number of cses of type 8 disese incresed from 24 to 32. Notbly in the lst 12 months, six of the nine IPD cses in <2 yers ge group nd eight of the eleven cses in the 2-4 yers ge group were due to type 19A. This totl of 14 cses of 19A IPD in the <5 yers ge group is mrked increse on the totl of two cses due to this serotype in this ge group in the previous 12-month period (Tble 3). Type 19A ws the mjor contributor to the significnt increse in IPD in the <2 yers ge group between the lst two 12-month periods (Tble 1). Invsive Pneumococcl Disese Qurterly Report, Jnury Mrch

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 PCV10 d A A Totl PCV C N A A F A B F F F A B F Other types e Totl non- PCV Cses reported in the first qurter of 2017 (Jnury-Mrch 2017). b Cses reported in the 12 months ending 31 Mrch c Cses reported in the 12 months ending 31 Mrch d The indictions for PCV10 include cross-protection ginst 19A disese. e Any of these other serogroups/serotypes ccounted for 5 IPD cses during the 12 months ending 31 Mrch Invsive Pneumococcl Disese Qurterly Report, Jnury Mrch

7 Tble 4 shows the immunistion sttus for cses notified in the Jnury Mrch 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 EpiSurv (ie, dt ws not mtched to the Ntionl Immunistion Register). Immunistion informtion ws recorded for five out of the eight cses. Two of the cses were recorded s not being immunised. Of the remining three cses, one cse ws due to PCV7 serotype (14) nd two cses were non- PCV13 types. Ethnicity ws recorded for 70 (92.1%) of the 76 IPD cses in the Jnury-Mrch 2017 qurter (Tble 5). The ge-stndrdised rtes of IPD were highest for the Pcific peoples (9.3 per 100,000, 16 cses) nd Māori (6.3 per 100,000, 23 cses) ethnic groups. The rtes for these two ethnic groups were, respectively, 15.5 nd 10.5 times higher thn the rte for the Europen or Other ethnic group (0.6 per 100,000, 24 cses) (Tble 5). In the Jnury-Mrch 2017 qurter, 67 (88.2%) of the 76 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 (3.4 per 100,000, 28 cses), 4.9 times the rte in the lest deprived res (0.7 per 100,000, 6 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, Jnury Mrch

8 Tble 4. Immunistion sttus of the invsive pneumococcl disese cses notified in the Jnury-Mrch 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 or 7F b Cses due to dditionl PCV13 serotypes: 3, 6A or 19A b Cses due to non- PCV13 serotypes b Totl b,c Number Number Number Number Number c 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 Cse due to serotype 14. Note: Immunistion sttus ws unknown for three cses who were eligible for PCV (not included in tble). Invsive Pneumococcl Disese Qurterly Report, Jnury Mrch

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, Jnury-Mrch 2017 qurter Age group (yers) Māori Pcific peoples Asin MELAA Europen or Other Cses Rte Cses Rte Cses Rte Cses Rte Cses Rte < Totl cses nd crude rte for ll ges b Age-stndrdised rte c Middle Estern/Ltin Americn/Africn. b Ethnicity ws recorded for 70 (92.1%) of cses in the Jnury-Mrch 2017 qurter. c 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, Jnury Mrch

10 Tble 6. Number nd percentge of invsive pneumococcl disese cses by quintiles of the 2013 New Zelnd deprivtion index nd ge group, Jnury-Mrch 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 Rte per 100, 000 popultion, bsed on the 2013 census dt from Sttistics New Zelnd. These rtes should not be compred with disese rtes used elsewhere in the report which hve been clculted using 2016 mid-yer popultion estimtes from Sttistics New Zelnd. d Accurte New Zelnd Deprivtion Index (NZDep13) dt ws vilble for 67 (88.2%) cses notified in the Jnury-Mrch 2017 qurter. Invsive Pneumococcl Disese Qurterly Report, Jnury Mrch