2015-2016 Influenza Season, Boston Infectious Disease Bureau Boston Public Health Commission
Boston Public Health Commission Influenza Surveillance: Boston, 2015-2016 Influenza cases diagnosed in Boston and confirmed by any laboratory test must be reported to the city health department (Boston Public Health Commission, BPHC).
Boston Public Health Commission Influenza Surveillance: Boston, 2015-2016 BPHC syndromic surveillance data are used to track influenza-like illness (ILI) visits at acute care sites in Boston. During the season, data are used to inform control measures and provide community situational awareness. Data for this report were analyzed by BPHC after the influenza season.
Number of Reported Cases %ILI ED Visits Boston Public Health Commission Reported Influenza Cases* and Percent of Emergency Department Visits Due to Influenza-Like Illness (ILI)**, Boston, 2015-2016 300 250 200 150 100 50 0 Influenza Cases %ILI ED Visits 4.0% 3.5% 3.0% 2.5% 2.0% 1.5% 1.0% 0.5% 0.0% -0.5% Week Ending Note: The 2015-2016 influenza season covers event dates between 10/1/2015-4/30/2016 *Reported cases: Boston residents only. **ED ILI visits: All visits to Boston EDs regardless of residence
Number of Reported Cases Boston Public Health Commission Reported Influenza Cases by Influenza Type, Boston Residents, 2015-2016 300 Influenza A Cases Influenza B Cases 250 200 150 100 50 0 Week Ending Note: The 2015-2016 influenza season covers event dates between 10/1/2015-4/30/2016
% ILI / All Visits Boston Public Health Commission Percent of Emergency Department Visits for Influenza-like Illness (ILI): Boston, 2013-2016* 3.0% 2013-2014 2014-2015 2015-2016 2.5% 2.0% 1.5% 1.0% 0.5% 0.0% Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug *All visits to Boston EDs regardless of residence
Boston Public Health Commission Characteristics of Reported Influenza Cases, Boston Residents, 2015-2016 Total Cases N=1747 Hospitalized 293 (17%) Died 14 (1%) Influenza A * 1414 (81%) Influenza B * 328 (19%) Male 743 (43%) Female 1004 (57%) Note: The 2015-2016 influenza season covers event dates between 10/1/2015-4/30/2016 *Excluded five cases who had both influenza types A and B
Age Group (years) Boston Public Health Commission Reported Influenza Cases, Boston Residents*, 2015-2016 Age Age (years) and Gender 65+ 65+ yrs 13% 45-64 5-17 yrs 11% 18-44 yrs 40% 18-44 Male <5 yrs 10% 45-64 yrs 26% 5-17 <5 Female 500 375 250 125 0 125 250 375 500 Number of Cases *Boston Population, 2010 Census Data
Age Group (yrs) Boston Public Health Commission Reported Influenza Cases by Age in Boston Residents, Compared to the Overall Boston Population*, 2015-2016 65+ 45-64 18-44 5-17 <5 0% 10% 20% 30% 40% 50% 60% Percent of Total Boston Population Reported Influenza Cases *Boston Population, 2010 Census Data
Race/Ethnicity Boston Public Health Commission Reported Influenza Cases by Race/Ethnicity in Boston Residents, Compared to the Overall Boston Population*, 2015-2016 White Black Latino Asian Other Unknown 0% 10% 20% 30% 40% 50% 60% Percent of Total Boston Population Reported Influenza Cases *Boston Population, 2010 Census Data
Boston Public Health Commission Characteristics of Hospitalized Influenza Cases by Age, Boston Residents, 2015-2016 Age Group (years) <5 5-17 18-44 45-64 65+ All Ages % Cases Hospitalized 13% 8% 7% 22% 48% 17% Median LOS* (days) 2 3 3 4 4 3 Oseltamivir treatment 91% 87% 96% 93% 94% 93% Asthma 26% 47% 37% 34% 25% 31% Cardiac Disease 4% 20% 10% 34% 59% 36% Chronic Obstructive Pulmonary Disease 0% 0% 0% 29% 42% 25% Diabetes 0% 7% 12% 28% 44% 28% Pneumonia 30% 13% 25% 40% 44% 37% Presented with fall** 0% 0% 0% 9% 13% 8% *LOS=length of stay **Presented with fall=cases who presented to a hospital as the direct result of a fall, but who were subsequently found to have laboratory-confirmed influenza
*Reported race: Asian or Other excluded due to small sample sizes **LOS=length of stay ***Presented with fall=cases who presented to a hospital as the direct result of a fall, but who were subsequently found to have laboratory-confirmed influenza Boston Public Health Commission Characteristics of Hospitalized Influenza Cases by Race, Boston Residents, 2015-2016 Reported Race* White Black Latino Total % Cases Hospitalized 18% 20% 16% 17% Median LOS** (days) 3 3 3 3 Oseltamivir treatment 92% 94% 93% 93% Asthma 22% 40% 31% 31% Cardiac Disease 40% 37% 27% 36% Chronic Obstructive Pulmonary Disease 43% 22% 9% 25% Diabetes 19% 34% 29% 28% Pneumonia 42% 38% 22% 37% Presented with fall*** 7% 8% 11% 8%
Boston Public Health Commission Influenza A vs. Influenza B Cases by Race/Ethnicity and Age Group, Boston Residents, 2015-2016 Race/Ethnicity White Black Latino Asian Total Influenza A 78% 85% 81% 85% 81% Influenza B 22% 15% 19% 15% 19% Age Group (years) <5 5-17 18-44 45-64 65+ Total Influenza A 84% 68% 79% 87% 87% 81% Influenza B 16% 32% 21% 13% 13% 19%
Boston Public Health Commission Characteristics of Hospitalized Influenza Cases by Influenza Type, Boston Residents, 2015-2016 Influenza A Influenza B % Cases Hospitalized 18% 12% Median LOS* (days) 3 3 Oseltamivir treatment 93% 90% Asthma 30% 36% Cardiac Disease 37% 28% Chronic Obstructive Pulmonary Disease 26% 18% Diabetes 29% 21% Pneumonia 39% 26% Presented with fall** 7% 18% *LOS=length of stay **Presented with fall=cases who presented to a hospital as the direct result of a fall, but who were subsequently found to have laboratory-confirmed influenza
Boston Public Health Commission Confirmed Influenza Cases and ILI ED Visits in Boston Residents, 2015-2016 Confirmed Influenza Cases, per 100,000 population, 10/1/2015-4/30/2016 ILI Emergency Department Visits, per 100,000 population, 10/1/2015-4/30/2016 Neighborhood Legend A/B=Allston/Brighton BB=Back Bay CH=Charlestown EB=East Boston FW=Fenway HP=Hyde Park JP=Jamaica Plain MT=Mattapan ND=North Dorchester RS=Roslindale RX=Roxbury SB=South Boston SD=South Dorchester SE=South End WR=West Roxbury
Metro Boston FNY % ILI % ILI Visits (Boston Hospitals) Boston Public Health Commission Comparison of ILI Using Flu Near You (FNY)** and Boston Hospital Syndromic* Data, 2013-2016 10 9 8 7 6 5 4 3 2 1 0 Metro Boston FNY % ILI % ILI ED Visits (Boston Hospitals) 3 2.5 2 1.5 1 0.5 0 *All visits to Boston EDs regardless of residence Week Ending **Flu Near You (FNY) compiles weekly data of ILI activity in the United States. The data come from short, weekly internet-based surveys completed by voluntary participants who indicate whether they are healthy or have experienced any of a short list of symptoms. The public may participate by enrolling in FNY at: https://flunearyou.org/
Boston Public Health Commission Influenza in Boston: 2015-2016 17% of reported cases were hospitalized. Despite current guidelines, not all hospitalized influenza cases were treated with an antiviral medication.
Boston Public Health Commission Influenza in Boston: 2015-2016 8% of hospitalized influenza cases sought healthcare due to a fall, not influenza. The elderly were more likely to present due to a fall. Information from a community participatory disease surveillance system correlated well with data from case reporting and syndromic surveillance.
Boston Public Health Commission
Infectious Disease Bureau P: (617) 534-5611 F: (617) 534-5905 www.bphc.org/cdc