Influenza Season, Boston

Size: px

Start display at page:

Download "Influenza Season, Boston"

Violet Martin
5 years ago
Views:

1 Influenza Season, Boston Infectious Disease Bureau Boston Public Health Commission

2 Boston Public Health Commission Influenza Surveillance: Boston, Influenza cases diagnosed in Boston and confirmed by any laboratory test must be reported to the city health department (Boston Public Health Commission, BPHC).

3 Boston Public Health Commission Influenza Surveillance: Boston, BPHC syndromic surveillance data are used to track influenza-like illness (ILI) visits at Emergency Departments (EDs) 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.

4 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, Influenza Cases %ILI ED 3.0% % 2.0% 1.5% 1.0% 0.5% 0.0% Note: The influenza season covers event dates between 10/1/2016-4/30/2017 *Reported cases: Boston residents only. **ED ILI visits: All visits to Boston EDs regardless of residence Week Ending

5 Number of Reported Cases Boston Public Health Commission Reported Influenza Cases by Influenza Type, Boston Residents, Influenza A Cases Influenza B Cases Week Ending Note: The influenza season covers event dates between 10/1/2016-4/30/2017

6 % ILI / All Visits Boston Public Health Commission 3.0% Percent of Emergency Department Visits* for Influenza-like Illness (ILI): Boston, ** % 2.0% 1.5% 1.0% 0.5% 0.0% Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug *ED ILI visits: All visits to Boston EDs regardless of residence Month **Predominating influenza A subtypes by season: : H3N2 (circulating virus was antigenically drifted from the vaccine strain) : H1N1 (circulating virus was well matched to vaccine strain) : H3N2 (circulating virus was well matched to vaccine strain)

7 Boston Public Health Commission Characteristics of Reported Influenza Cases, Boston Residents, Total Cases N=3285 N (%) Hospitalized 579 (18%) Died (among total cases) 14 (0.4%) Died (among hospitalized cases) 14 (2.4%) N (%) Influenza A * 2383 (73%) Influenza B * 897 (27%) N (%) Male 1380 (42%) Female 1905 (58%) Note: The influenza season covers event dates between 10/1/2016-4/30/2017 *Excludes five cases who either had both influenza types A and B, or who tested positive with a diagnostic test that does not differentiate between flu types

8 Age Group (years) Boston Public Health Commission Reported Influenza Cases, Boston Residents*, Age Age and Gender Female Male 85+ yrs 5% 85+ <5 yrs 10% yrs 16% 5-17 yrs 22% yrs 30% yrs 17% < Number of Cases *Boston Population, 2010 Census Data

9 Age Group (years) Boston Public Health Commission Reported Influenza Cases by Age in Boston Residents, Compared to the Overall Boston Population*, Boston Population Reported Influenza Cases <5 0% 10% 20% 30% 40% 50% 60% *Boston Population, 2010 Census Data Percent of Total

10 Race/Ethnicity Boston Public Health Commission Reported Influenza Cases by Race/Ethnicity in Boston Residents, Compared to the Overall Boston Population*, Boston Population Reported Influenza Cases White Black Latino Asian Other** Unknown 0% 10% 20% 30% 40% 50% 60% Percent of Total *Boston Population, 2010 Census Data **Other is inclusive of American Indian, Alaskan Native, Native Hawaiian, Pacific Islander, and unspecified other race

11 Boston Public Health Commission Influenza A vs. Influenza B Cases by Race/Ethnicity and Age Group, Boston Residents, Race/Ethnicity White Black Latino Asian Other* Total Influenza A 72% 73% 74% 71% 71% 73% Influenza B 28% 27% 26% 29% 29% 27% Age Group (years) < Total Influenza A 75% 71% 73% 69% 76% 78% 73% Influenza B 25% 29% 27% 31% 24% 22% 27% *Other is inclusive of American Indian, Alaskan Native, Native Hawaiian, Pacific Islander, and unspecified other race

12 Boston Public Health Commission Characteristics of Reported Influenza Cases* >64 Years of Age, by Age Range: Boston, Gender Age Group (years) N=514 N=167 Male 41% 39% Female 59% 61% White 43% 51% Black 32% 25% Race Latino 15% 14% Asian 8% 7% Other** 3% 2% Hospitalized 43% 67% Died 1% 4% *Reported cases: Boston Residents only. **Other is inclusive of American Indian, Alaskan Native, Native Hawaiian, Pacific Islander, and unspecified other race

13 *Data on length of stay, treatment, and co-morbidities missing for 33 of 579 hospitalized cases **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 Age, Boston Residents, Age Group (years) < All Ages % Cases Hospitalized 3% 5% 21% 43% 67% 18% Median LOS** (days) Oseltamivir treatment 86% 88% 90% 95% 95% 92% Asthma 45% 26% 30% 26% 27% 28% Cardiac Disease 62% 10% 35% 59% 49% 52% Chronic Obstructive Pulmonary Disease 41% 28% 16% 24% 21% 23% Diabetes 50% 30% 33% 36% 37% 35% Pneumonia 28% 22% 24% 31% 31% 28% Presented with fall*** 3% 8% 9% 8% 14% 9%

14 *Data on length of stay, treatment, and co-morbidities missing for 33 of 579 hospitalized cases **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/Ethnicity, Boston Residents, Reported Race/Ethnicity White Black Latino Asian Total % Cases Hospitalized 22% 19% 14% 15% 18% Median LOS** (days) Oseltamivir treatment 88% 95% 98% 93% 92% Asthma 22% 27% 45% 15% 28% Cardiac Disease 55% 45% 45% 41% 48% Chronic Obstructive Pulmonary Disease 32% 16% 19% 15% 23% Diabetes 32% 38% 38% 33% 35% Pneumonia 34% 24% 29% 19% 28% Presented with fall*** 11% 9% 7% 11% 9%

15 Boston Public Health Commission Characteristics of Hospitalized* Influenza Cases by Influenza Type, Boston Residents, Influenza A Influenza B % Cases Hospitalized** 18% 16% # of Deaths 14 0 Median LOS*** (days) 3 3 Oseltamivir treatment 93% 91% Asthma 30% 21% Cardiac Disease 49% 44% Chronic Obstructive Pulmonary Disease 24% 19% Diabetes 35% 36% Pneumonia 28% 29% Presented with fall**** 9% 7% *Data on length of stay, treatment, and co-morbidities missing for 33 of 579 hospitalized cases **Each percentage indicates the proportion of all cases with the corresponding influenza type (A or B) who were hospitalized ***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

16 Boston Public Health Commission Characteristics of Hospitalized* Influenza Cases >64 Years of Age, by Age Range: Boston, Age Group (years) % Hospitalized 43% 67% Median LOS** (days) 3 3 Oseltamivir treatment 95% 95% Asthma 26% 27% Cardiac Disease 51% 51% Chronic Obstructive Pulmonary Disease 24% 21% Diabetes 36% 37% Pneumonia 31% 31% Presented with Fall*** 8% 14% *Data on length of stay, treatment, and co-morbidities missing for 33 of 579 hospitalized cases **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 Emergency Department (ED) Visits in Boston Residents, 2016-2017 Confirmed Influenza Cases, per 100,000 population,

17 Boston Public Health Commission Confirmed Influenza Cases and ILI Emergency Department (ED) Visits in Boston Residents, Confirmed Influenza Cases, per 100,000 population, 10/1/2016-4/30/2017 ILI ED Visits, per 100,000 population, 10/1/2016-4/30/2017 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

18 Metro Boston FNY % ILI % ILI Visits (Boston Hospitals) Boston Public Health Commission Comparison of ILI Using Flu Near You (FNY)** and Boston Emergency Department (ED) Syndromic* Data, Metro Boston FNY % ILI % ILI ED Visits (Boston Hospitals) Week Ending *All visits to Boston EDs regardless of residence **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:

19 Boston Public Health Commission Influenza in Boston: % of reported cases were hospitalized. Despite current guidelines, not all hospitalized influenza cases were treated with an antiviral medication.

20 Boston Public Health Commission Influenza in Boston: % of hospitalized influenza cases sought healthcare due to a fall, not influenza. The elderly were more likely to present due to a fall, most often associated with concomitant dehydration due to influenza infection Information from a community participatory disease surveillance system correlated well with data from case reporting and syndromic surveillance.

21 Infectious Disease Bureau P: (617) F: (617)

Influenza Season, Boston

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