April 3, 2 Week #17, ending /26/ INFLUENZA WATCH The purpose of the weekly is to summarize current influenza surveillance in San Diego County. Please note that reported weekly data are preliminary and may change due to delayed submissions and additional laboratory results. Current Week Report Contents Page 1: Overview & Indicators Page 2: Virus Characteristics Pages 3 7: Trend graphs Page 7: Reporting Information Current (ending 1/6/21) 2,992 new influenza detections reported: Elevated level 11% influenza like illness (ILI) among emergency department visits: Elevated level 7 new influenza related deaths reported this week 5 new ICU cases reported this week 9% of deaths registered with pneumonia and/or influenza: Expected level Current Season Summary 1,32 Total Cases ICU Cases 91 Deaths 5 Outbreaks * 3.1%.3% Virus Characteristics.2%.2%.9% Influenza A 15.% 79.9% Influenza A (H1N1)pdm9 Influenza A (H3) Seasonal Influenza B Influenza B/Yamagata Influenza B/Victoria Influenza A/B * At least one case of laboratory-confirmed influenza in a setting experiencing 2 cases of influenza like illness (ILI) within a 72-hour period. Table 1. Influenza Surveillance Indicators Prior 3 Year FY 217 1* FY 216 17 Average** Week Week Week Week Indicator 1 52 FYTD # 1 FYTD # 1 FYTD # All influenza detections reported (rapid or PCR) 2,992 3,35 1,32 76 1,352 2 1,9 Percent of emergency department visits for ILI 11% 13% % 5% Percent of deaths registered with pneumonia and/or influenza 9% 9% % 7% Number of influenza related deaths reported^ 7 91 3 2 5 # FYTD=Fiscal Year To Date (FY is July 1 - June 3, Weeks 27-26). Total deaths reported in prior years: 7 in 216-17, 6 in 215-16, and 97 in 2-15. * Previous weeks case counts or percentages may change due to delayed processing or reporting. ** Includes FYs 2-15, 215-16, and 216-17. ^ Current FY deaths are shown by week of report; by week of death for prior FYs. Page 1 of 7
April 3, 2 Week #17, ending /26/ Influenza Activity in San Diego County Remains High A high number of influenza cases continue to be reported in San Diego County each week. The County of San Diego Health and Human Services Agency is closely monitoring the impact of influenza on local healthcare capacity and utilization. Local hospitals and healthcare systems are currently effectively managing the increased workload. This includes the successful use of telephone triage by healthcare providers and the increased evaluation of influenza in non-urgent settings. Presumptive diagnosis and treatment without testing for influenza are increasingly being utilized in the community. This may be contributing to the decrease in the absolute number of reported labconfirmed cases in (21) compared to Week 52 (217). Three ongoing and critical actions to reduce the local impact of influenza are: 1) Vaccinate everyone over six months of age who has not yet received the annual influenza shot. It s not too late to be vaccinated! Media reports of a low (1%) vaccine effectiveness (VE) in Australia of one component of this season s vaccine are inappropriately dissuading some people from getting vaccinated. Initial VE estimates for this season s vaccine in the US will be available in February. According to the Centers for Disease Control and Prevention (CDC), overall VE against all circulating flu viruses in the US is likely to be similar to last year (39%). 2) Practice everyday preventive steps to stop the spread of influenza. Avoid close contact with anyone who is ill and remain at home when sick for at least 2 hours after fever is gone. See everyday preventive actions and nonpharmaceutical interventions for more information about actions individuals and communities can take to stop the spread of influenza. 3) Use antiviral medications to treat influenza based on CDC guidelines. Generic oseltamivir is reported to be in short supply nationwide; however the brand version (Tamiflu ) is available according to the manufacturer. Individual pharmacies may not have specific influenza antiviral medications due to increased demand, so patient may need to check with several pharmacies to fill a prescription to treat influenza. Patients are encouraged to call pharmacies ahead of time and to have a family member or friend pick up prescriptions to minimize exposure to others. Providers who have supply issues should inform the County Epidemiology Program during normal working hours at 619-692- 99. Table 2. Influenza Detections Reported, FY 217 1* Total Positive Test Type/Subtype FY To Date Influenza A 2,53,251 Influenza A(H1N1) Pandemic 29 3 Influenza A (H3) Seasonal 26 321 Influenza B 73 1,591 Influenza B/Victoria 1 17 Influenza B/Yamagata 1 22 Influenza A/B 3 92 Total 2,992 1,32 * FY is July 1 - June 3. No further characterization performed, or results were not yet available at time of publication. Note: Totals may change due to further laboratory findings. Page 2 of 7
Figure 1. Percent of Emergency Department Visits for Influenza like Illness by Week and FY 12 1 Percent 6 2 27 29 31 33 35 37 39 1 3 5 7 9 51 1 3 5 7 9 11 13 15 17 19 21 23 25 Week Number 211 12 212 13 213 2 15 215 16 216 17 217 1 Page 3 of 7
Cumulative Number Influenza Reports 12 1 6 Figure. Cumulative Influenza Case Reports by Episode Week & Season 217 1 FYTD 2 27 29 31 33 35 37 39 1 3 5 7 9 51 1 3 5 7 9 11 13 15 17 19 21 23 25 Week Number 217 1 216 17 215 16 2 15 213 212 13 211 12 21 11 29 1 2 9 Page of 7
ec etoege cyepatet sts Visit Baseline& sforinflue nza-likeiluper95% Threshol nesbywe dvalues(sekandfy Compared erflingme to5-year thod) 12 1 6 2 2733 11723135 27212352 931172313 527212 352912 532396115 3 3 5 56 67 7 ILI% Ba seline Uper95 %Threshold County of San Diego Percent of Emergency Department Visits 12 1 6 2 Figure 5. Percent of San Diego County Emergency Department Visits for Influenza-like Illness by Week and FY Compared to 5-Year Baseline & Upper 95% Threshold Values (Serfling Method) 27 3 1 3 1 17 2 31 3 5 52 7 21 2 35 2 9 3 1 17 2 31 3 5 52 7 21 2 35 2 9 11 1 25 32 39 6 1 15 22 212 13 213 2 15 215 16 216 17 217 1 ILI% Baseline Upper 95% Threshold 1 Figure 6. Percent of San Diego County Deaths Registered with Pneumonia and/or Influenza by Week and FY Compared to Prior 5-Year Baseline & Upper 95% Threshold Values (Serfling Method) 16 Percent of Deaths 12 1 6 2 27 1 212 13 3 17 31 5213 7 21 35 9 2 15 1 2 3 52 215 16 2 216 17 1 32 6 217 1 22 %P&I Deaths Baseline Upper 95% Threshold Page 5 of 7
12 Figure 7. Influenza Deaths by Type and Season Both Influenza A and Influenza B Number of Deaths 1 6 Influenza A/B, Type Unknown Influenza B Pandemic H1N1 Influenza A\H3 Influenza A, No Subtype 5 65 7 97 6 7 91 25 2 9 25 6 26 7 27 2 9 29 1 21 11 211 12 Season 212 13 213 2 15 215 16 216 17 217 1 FYTD 12 Figure. Influenza Deaths by Age and Season 1 <1 yr 1 17 1 3 97 7 91 Number of Deaths 6 35 6 65+ 5 65 7 6 25 2 9 25 6 26 7 27 2 9 29 1 21 11 211 12 Season 212 13 213 2 15 215 16 216 17 217 1 FYTD Page 6of 7
Episode week is the week of symptom onset, or earliest available date in which the case is identified. Influenza Reporting in San Diego County Local providers are encouraged to report laboratory positive influenza detections to the County Epidemiology Program by FAX (5) 715 65. Please fax a Case Report Form and/or a printed laboratory result, and indicate if the patient was admitted to ICU or died, and/or is a resident of a congregate living facility. For questions regarding sending specimens to Public Health Laboratory (PHL), call (619) 692 5. Click here for the updated PHL PCR Test Request Form. Contact the Epidemiology Program with any questions at (619) 692 99 or by email to: EpiDiv.HHSA@sdcounty.ca.gov. Resources San Diego County Influenza Surveillance Weekly Slide Deck presentation version of this report County of San Diego Immunization Program www.sdiz.org California Department of Public Health Influenza Centers for Disease Control and Prevention Influenza Surveillance Weekly Report Page 7of 7