ISSN 2324-3589 Hospital Surveillance SARI, Influenza and Respiratory Pathogens Monthly Report, November 15 SUMMARY During weeks 45-48 (2 November 29 November 15), influenza activity decreased in hospital surveillance in Auckland and Counties Manukau District Health Boards. SARI surveillance SARI surveillance: There were 888 acute admissions to ADHB and CMDHB hospitals this month. Of the 46 patients with suspected respiratory infections, 117 (25.4%) patients met the SARI case definition. Six SARI cases have been admitted to ICU and two SARI related deaths were reported. The monthly SARI incidence was 8.7 per population, higher than the incidence during the same period last year. The SARI related influenza incidence was.2 per population. Respiratory pathogen surveillance Influenza virus: During this month 58 SARI specimens were tested, 2 were positive for influenza viruses. For details, see Table 2 and Figure 2. Non-influenza respiratory viruses: For cumulative totals and temporal distribution, see Table 3 and Figure 3. The surveillance for hospital-based severe acute respiratory infections (SARI) provides evidence to inform public health and clinical practice to reduce the impact of influenza virus infection and other important respiratory pathogens. As part of the Southern Hemisphere Influenza and Vaccine Effectiveness Research & Surveillance (SHIVERS) project, this monthly report summarises data obtained from the Auckland and Counties Manukau District Health Boards (ADHB and CMDHB) of New Zealand with a population of 95,622 people. The report includes incidence, demographic characteristics, clinical outcomes and aetiologies for hospital SARI cases including ICU admissions and deaths for the past week as well as the cumulative period since 27 April 15. Note: Data in this report are provisional and may change as more cases are assessed and information is updated. Data were extracted on 4 December 15. ACKNOWLEDGEMENT We acknowledge the support of the US Department of Health and Human Services, Centers for Disease Control and Prevention (CDC) and the New Zealand Ministry of Health. The SHIVERS project is a five year research cooperative agreement between the Institute of Environmental Science and Research (ESR) in New Zealand and US CDC s National Center for Immunization and Respiratory Diseases (NCIRD) Influenza Division. SARI surveillance was established and funded by the US CDC under award number 5U1IP48-4 and continues to operate through funding from the New Zealand Ministry of Health.
18 22 24 26 28 32 34 36 38 4 42 44 46 48 5 52 2 4 6 8 12 14 16 Incidence per residents SEVERE ACUTE RESPIRATORY INFECTION Severe acute respiratory infection (SARI) There were 888 acute admissions to ADHB and CMDHB hospitals during weeks 45-48, ending 29 November 15. A total of 46 patients with suspected respiratory infections were assessed in these hospitals. Of these, 117 (25.4%) patients met the SARI case definition. Six SARI cases have been admitted to ICU and two SARI related deaths were reported during weeks 45-48. Of the 117 SARI cases admitted last month, 79 were residents of ADHB and CMDHB. This gives a monthly SARI incidence of 8.7 per population. 46 SARI residents had specimens tested for influenza viruses, 2 were positive for influenza viruses. This gives a SARI related influenza incidence of.2 per patient population. Figure 1 Weekly resident SARI and influenza incidence since 27 April 15 and previous seasons SARI incidence 18 16 14 12 8 6 4 2 SARI cases - all others SARI cases - influenza positive 12/3 SARI cases 13/4 SARI cases 14/5 SARI cases May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr Week (15/16) Since 27 April 15, a total of 22 SARI cases were identified. This gives a SARI proportion of 26.2 per acute hospitalisations (Table 1). 156 SARI cases have been admitted to ICU and 33 SARI related deaths were reported during this period. Of the 22 SARI cases, 1664 were ADHB and CMDHB residents, giving a SARI incidence of 183.7 per population (Table 1). Among the 14 tested SARI cases who were ADHB and CMDHB residents, 1 (21.2%) had positive influenza virus results. This gives a SARI related influenza incidence of 33.2 per population.
Table 1 Demographic characteristics of SARI cases and related influenza cases, since 27 April 15 SARI Cases (%) Cases per hospitalisations Influenza positive 1 SARI cases (%) SARI incidence (per ) Influenza Cases Influenza incidence (per ) Overall 85176 5348 22 (41.7) 26.2 321 (.4) 1664 183.7 1 33.2 Age group (years) <1 3569 462 129.4 38 (9.7) 428 3169. 34 251.7 1 to 4 6255 4 67.1 47 (14.2) 368 695.9 43 81.3 5 to 19 9854 114 11.6 21 (23.6) 93 48.3 19 9.9 to 34 15743 116 7.4 47 (43.5) 112 53.7 46 22.1 35 to 49 128 142 11.1 36 (26.9) 137 71.7 34 17.8 5 to 64 14414 13.9 6 (33.1) 194 128.9 58 38.5 65 to 79 137 211 15.4 4 (21.5) 5 28.5 4 54.7 8 and over 8821 128 14.5 27 (23.7) 127 542. 27 115.2 Unknown 437 5 (12.8) - - Ethnicity Maori 11294 392 34.7 6 (18.6) 348 349.8 54 54.3 Pacific Peoples 1867 72 38.9 132 (21.9) 682 494.2 1 94.2 Asians 13294 163 12.3 29 (19.6) 151 71.8 27 12.8 European and others 4198 536 12.8 95 (.6) 483 1.3 9 22.4 Unknown 593 437 5 (12.8).. Hospitals ADHB 48559 2755 97 17 (25.8) 64 138.4 156 35.8 CMDHB 36617 2593 126 34.4 151 (16.5) 6 225.9 145.9 Sex Characteristics Admissions Assessed SARI & influenza cases among all hospital patients SARI & influenza cases among ADHB & CMDHB residents Female 44682 88 19.7 164 (21.7) 825 177.4 159 34.2 Male 4492 912 22.5 152 (19.5) 838 19.3 142 32.2 Unknown 2 438 5 (12.5) 1 - - 1 Proportion of cases tested which were positive for influenza viruses
RESPIRATORY PATHOGEN SURVEILLANCE Influenza virus During weeks 45-48, 58 SARI specimens were tested; 2 were positive for influenza viruses. Since 27 April 15, a total of 1677 SARI specimens were tested, 328 (19.6%) were positive for influenza with the following viruses (see Table 2). Table 2 Influenza viruses among SARI cases since 27 April 15 Influenza viruses SARI Cases ICU Deaths No. of specimens tested 1677 15 21 No. of positive specimens (%) 1 328 (19.6) 23 (15.3) 3 (14.3) Influenza A 198 11 2 A (not subtyped) 8 8 1 A (H1N1)pdm9 1 A(H1N1)pdm9 by PCR A/California/7/9 (H1N1) - like 1 A(H3N2) 117 3 1 A(H3N2) by PCR 1 3 1 A/Switzerland/9715293/13 (H3N2) - like 7 Influenza B 1 12 1 B (lineage not determined) 67 4 B/Yamagata lineage 27 1 B/Yamagata lineage by PCR 8 B/Phuket/73/13 - like 19 1 B/Victoria lineage 36 7 1 B/Victoria lineage by PCR 14 3 B/Brisbane/6/8 - like 22 4 1 Influenza and non-influenza co-detection (% +ve) 22 (6.7) 1 (4.3) (.) 1 Number of specimens positive for at least one of the listed viruses; note a specimen may be positive for more than one virus The recommended influenza vaccine formulation for New Zealand in 15 is: A(H1N1) - an A/California/7/9 (H1N1)pdm9-like strain* A(H3N2) - an A/Switzerland/9715293/13 (H3N2)-like strain B - a B/Phuket/73/13-like strain * Note: A/California/7/9 (H1N1)-like strain is an influenza A(H1N1)pdm9 strain.
Non-influenza respiratory pathogens Since 27 April 15, a total of 771 SARI specimens were tested for non-influenza viruses, 412 (53.4%) were positive with the following viruses (see Table 3). Table 3 Non-influenza respiratory viruses among SARI cases, since 27 April 15 Non-influenza respiratory viruses SARI Cases ICU Deaths No. of specimens tested 771 29 6 No. of positive specimens (%) 1 412 (53.4) 15 (51.7) 3 (5.) Respiratory syncytial virus (RSV) 147 4 1 Parainfluenza 1 (PIV1) 3 Parainfluenza 2 (PIV2) 5 1 Parainfluenza 3 (PIV3) 44 2 1 Rhinovirus (RV) 94 4 1 Adenovirus (AdV) 135 9 2 Human metapneumovirus (hmpv) 49 2 1 Enterovirus 9 1 Single virus detection (% of positives) 347 (84.2) 9 (6.) 2 (66.7) Multiple virus detection (% of positives) 65 (15.8) 6 (4.) 1 (33.3) 1 Number of specimens positive for at least one of the listed viruses; note a specimen may be positive for more than one virus
Number of viruses Proportion positive Number of viruses Proportion positive Figure 2 Temporal distribution of the number and proportion of influenza viruses from SARI specimens by type and week 1 5 45 4 35 25 15 5 A (Not subtyped) A(H3N2) A(H1N1)pdm9 B (Lineage not determined) B (Yamagata lineage) B (Victoria) Proportion positive for influenza 18 22 24 26 28 32 34 36 38 4 42 44 46 48 5 52 2 4 6 8 12 14 16 Week (15/16) 9 8 7 6 5 4 Figure 3 Temporal distribution of the number and proportion of non-influenza viruses from SARI specimens by type and week 1 25 15 5 18 22 24 26 28 32 34 36 38 4 42 44 46 48 5 52 2 4 6 8 12 14 16 Week (15/16) RSV parainfluenza 1 parainfluenza 2 parainfluenza 3 rhinovirus adenovirus hmpv enterovirus Proportion positive for non-influenza pathogen 9 8 7 6 5 4 1 Figures for recent weeks will be underestimates due to time lag in receiving laboratory test results.
APPENDIX Recent global experience with pandemic influenza A(H1N1)pdm9 highlights the importance of monitoring severe and mild respiratory disease to support pandemic preparedness as well as seasonal influenza prevention and control. An enhanced, active, population-based surveillance has been established for hospital-based severe acute respiratory infection (SARI) cases in Auckland Counties Manukau District Health Boards (ADHB and CMDHB), which together provide healthcare for 95,622 people. The aims of SARI surveillance are: 1) to measure the burden of severe disease caused by influenza and other respiratory pathogens; 2) to monitor trends in severe disease caused by influenza and other respiratory pathogens; 3) to identify high risk groups that should be prioritized for prevention and treatment; 4) to monitor antigenic, genetic and antiviral characteristics of influenza viruses associated with severe disease; 5) to provide a study base to estimate the effectiveness of influenza vaccine. The SARI surveillance protocol was developed by: Sue Huang, Sally Roberts, Colin McArthur, Michael Baker, Cameron Grant, Deborah Williamson, Adrian Trenholme, Conroy Wong, Susan Taylor, Lyndsay LeComte, Graham Mackereth, Don Bandaranayake, Tim Wood, Ange Bissielo, Ruth Seeds, Nikki Turner, Nevil Pierse, Paul Thomas, Richard Webby, Diane Gross, Jazmin Duque, Mark Thompson and Marc-Alain Widdowson. The SHIVERS project is a multi-centre and multi-disciplinary collaboration between ESR, Auckland District Health Board, Counties Manukau District Health Board, University of Otago, University of Auckland, participating sentinel general practices, Primary Health Organisations (Procare, Auckland and East Tamaki Healthcare), Auckland Regional Public Health Service, the US Centers for Disease Control and Prevention and WHO Collaborating Centre at St Jude Children s Hospital in Memphis, USA.
NOTES ON INTERPRETATION SARI case definition: An acute respiratory illness with a history of fever or measured fever of 38 C, AND cough, AND onset within the past days, AND requiring inpatient hospitalisation (defined as a patient who is admitted under a medical team and to a hospital ward or assessment unit). PCR method for influenza virus: ADHB Laboratory and ESR s National Influenza Centre (NIC) use CDC s real-time PCR protocol (http://www.accessdata.fda.gov/cdrh_docs/pdf8/k857.pdf.); CMDHB laboratory uses commercially available multiplex real-time PCR assay from AusDiagnostics. Ongoing validation between the AusDiagnostic assays and CDC s influenza assay will be conducted on a weekly basis. The real-time PCR assay for non-influenza respiratory viruses (respiratory syncytial virus, parainfluenza virus types 1-3, human metapneumovirus, rhinovirus and adenovirus) was obtained from the U.S. Centers for Disease Control and Prevention and are available on request. Note: The rhinovirus PCR detects mostly rhinovirus with slight cross-reactivity against enterovirus. The surveillance week is Monday to Sunday inclusive, and data are extracted on the subsequent Tuesday. Results from previous weeks will be revised as data are updated (laboratory test results in particular may be delayed). This monthly report is compiled by ESR. For more information please contact: Tim Wood: T:+64 4 529 611; E: Tim.Wood@esr.cri.nz Sue Huang: T:+64 4 529 66; E: Sue.Huang@esr.cri.nz