2009 H1N1 Mid-Term Review Winnebago County, Illinois April 2009-February 2010

Transcription

1 2009 H1N1 Mid-Term Review Winnebago County, Illinois April 2009-February 2010 A Publication of the Winnebago County Health Department, June H1N1 Influenza Summary Report June 2010, Page 1

2 Table of Contents I. Executive Summary - 2 II. Background - 4 III. Purpose - 5 IV. Materials and Methods - 6 V. Influenza-Like Illness - 7 VI. Cases - 15 VII. Hospitalizations - 19 VIII. Percent of Hospitalizations - 23 IX. Laboratory Submissions - 25 X. Projected Estimates of Actual H1N1 Spread - 26 XI. Vaccine Coverage - 29 XII. Media Coverage - 33 XIII. Discussion - 37 XIV. Acknowledgments - 39 XV. Works Cited - 40 XVI. Additional Tables H1N1 Influenza Summary Report June 2010, Page 2

3 I. Executive Summary The mission of the Winnebago County Health Department is to Prevent disease, promote health and enlist the community in efforts to improve the health of all Winnebago County residents. This goal is achieved through routine inspections, health promotion programs, health clinics, vaccinations and disease surveillance. In April of 2009, a unique strain of the influenza virus, labeled 2009 H1N1, or commonly referred to as Swine Flu, was detected in some of the citizens of Winnebago County. Detailed epidemiological surveillance data, vaccine coverage and media coverage delivered during the 2009 H1N1 pandemic follows. This document illustrates how the efforts of the Winnebago County Health Department, in association with other public and private enterprises, responded to the 2009 H1N1 influenza pandemic, and the numbers, confirmed and suspected, with the spread of the virus H1N1 Influenza Summary Report June 2010, Page 3

4 II. Background In early April of 2009, Mexican health officials released multiple reports of febrile respiratory illness. By mid-april, the Centers for Disease Control and Prevention (CDC) had reports of similar infections. Laboratory findings determined to be from swine influenza A, now known as novel 2009 H1N1 (H1N1) (1). US cases typically presented with a fever and cough (1). Early numbers indicated the majority of cases were found in the children under the age of 18 (2). This is different from seasonal flu, which typically affects those over 65 years in age. People with certain pre-existing conditions, such as asthma and diabetes, were also identified to be at significantly higher risk than those without those conditions (3). Symptoms of the H1N1 flu are similar to seasonal flu. Although cough and fever were the two main symptoms of the H1N1 flu, other symptoms included: shortness of breath, fatigue, chills, sore throat, headache and vomiting (3). The incubation period for H1N1 influenza is also similar to seasonal flu, averaging from 2 to 3 days (3). On April 28, 2009, the Chicago Department of Public Health identified the first case of H1N1 flu in the city (4). On May 2, the Winnebago County Health Department received confirmation of the first H1N1 case in a resident of the county. A communicable disease investigation was initiated, questionnaires referencing symptom onset, symptom manifestation and any potential disease source (work, school, etc.) were administered to all patients with a confirmed positive H1N1 diagnosis. There appeared to be four different periods of the pandemic since April The first period, or Wave 1, began with the first identified case in the United States on April 21, to June 6, The period from June 6 to August 29, 2009 is called the latent period, due to the decreased number of cases. The third period, August 30 to December 12, 2009, is Wave 2, when case reports increased dramatically. From the period of December 13 to February 27 are included in the post-wave period H1N1 Influenza Summary Report June 2010, Page 4

5 III. Purpose This comprehensive report is intended to be an in-depth look at the H1N1 flu within Winnebago County from April 2009 to February Topics covered include: Influenza-like Illness (ILI), confirmed cases, reported hospitalizations, percentage of hospitalizations, laboratory submissions, H1N1 projections and vaccine information. Data is current as of the date of publication and data are subject to change H1N1 Influenza Summary Report June 2010, Page 5

6 IV. Materials and Methods There were several methods of data collection, the first being INEDSS (Illinois National Electronic Disease Surveillance System). Positive H1N1 cases were reported through the INEDSS system, fax reports, and laboratory confirmation results. Questionnaires were completed from interviews with confirmed cases (or if a patient interview was not possible, an Infection Control Practitioner or family member) and entered in to appropriate data-collection spreadsheets. ESSENCE (Electronic Surveillance System for the Early Notification of Community-based Epidemics) data on ILI and discharge diagnosis from sentinel sites was utilized, along with school absenteeism reports, CDC notifications, projections and reports H1N1 Influenza Summary Report June 2010, Page 6

7 V. Influenza-Like Illness Influenza-Like Illness (ILI) is monitored by week on a year-round basis by Epidemiologic and Communicable Disease staff at the Winnebago County Health Department. Previous trends illustrate a peak in ILI activity which usually occurs during the traditional influenza season (Week 41, October 11 of 2009, through Week 25, June 26 of 2010). With the H1N1 flu, there were 2 separate peaks, the first occurring after the seasonal influenza peak of the 2009 season and the second right at the beginning of the 2010 seasonal influenza season. Figure 5.01 shows the ILI activity for Winnebago County. All ILI figures are calculated using ESSENCE. Figure 5.01 Note in the above graph the increase in ILI activity in weeks 16 through 19, fairly low levels from week 20 through week 38, and the second large spike from weeks 39 through 49. Figure 5.02, as seen on page 8, shows the association between Winnebago County and data from the entire northern Illinois region H1N1 Influenza Summary Report June 2010, Page 7

8 Figure 5.02 The data are similar when comparing Winnebago County to regional data. However, the ILI activity seen in Winnebago County is higher (18.1%) than the region (6.4%) during the second peak. Figure 5.03, below, shows the ILI activity from week 15, 2009 through week 4, 2010 for Cook County, the city of Chicago, DuPage County, Kane County and Winnebago County. Figure 5.03 Much like Figure 5.02, Figure 5.03 has very similar peaks. Both DuPage and Kane counties saw higher peaks than the region as a whole, much like the ILI activity in Winnebago County. The first peak commences earlier in the other four jurisdictions than in Winnebago County, but the second peak arrived at the same time, Week 43, in all five jurisdictions H1N1 Influenza Summary Report June 2010, Page 8

9 Figure 5.04 Figure 5.04, above, shows ILI activity for Winnebago County by the following age groups: 0-4 years, 5-17 years, years, and 65 years and over. For those groups 0-4 and 5-17 years, data was higher than the average, while activity for those aged was slightly below average. For those aged 65 and over, the data was near 0% for much of the H1N1 outbreak. For all four age groups, the first peak, the latent period, and the second peak are easily identified. For more graphs showing the breakout of different age groups versus regional or jurisdictional trends, refer to Appendix A. As previously seen in Figure 5.01, there are 2 distinct peaks, with a period in between with low levels of ILI activity. Figure 5.05 shows the breakout of ILI activity during Wave 1. Figure H1N1 Influenza Summary Report June 2010, Page 9

10 ILI peaked in week 17, at 4.2% of ED visits, for the region and in week 18, at 5% of ED visits, for Winnebago County. Figure 5.06 The data in Figure 5.06, above, show the continued decline, despite being high for the summer. These levels remain constant in to Wave 2, with the large increase in ILI activity in week 43. Figure 5.07 This large increase in ILI activity in Figure 4.07 is mirrored in both regional and Winnebago County data. Figure 5.08 shows the Wave 2 breakdown by jurisdiction within Northeastern Illinois. To see other waves by jurisdiction, refer to Appendix A H1N1 Influenza Summary Report June 2010, Page 10

11 Figure 5.08 The increase in ILI activity is very similar in Figures 5.07 and 5.08, and provides a clear illustration of the similarities between Winnebago, Kane and DuPage counties. Figure 5.09, below, shows the breakout of ILI activity from week 50 of 2009 to week 8 of The leveling out of ILI activity is shown after the end of the second wave. Figure 5.09 Looking by age group during the separate waves exclusively for Winnebago County, it is visible that the majority of ILI activity occurred in those in age groups 0-4 and H1N1 Influenza Summary Report June 2010, Page 11

12 Figure 5.10 Figure 5.10, above, shows the age breakout for Wave 1 in Winnebago County. The levels of ILI activity are highest in the 0-4 year age group, at 16%. Figure 5.11, below, shows the same trend, with some similar increases in the 5-17 year age group, at 7.4%. Figure H1N1 Influenza Summary Report June 2010, Page 12

13 Figure 5.12 The results from Figure 5.12, above shows an increase in ILI activity for the 0-4 year age group, peaking at 29.1% (Week 42) of visits due to ILI, and an additional increase in ILI activity for the 5-17 year age group, with the data peaking at 34.9% (Week 43) of visits for ILI, completing the surveillance information by age. Figure 5.13, below, shows data that closely resembles data from wave 1, but the decrease in activity from the second peak is apparent. Proceed to Appendix A for further breakdowns of age by wave. Figure H1N1 Influenza Summary Report June 2010, Page 13

14 A second way ILI was tracked was through school absenteeism data. Schools were requested to report daily absenteeism due to ILI to the health department. Overall, two school districts were closed (Kinnikinnick and South Beloit) for 2 days each (5,6). Both of these school districts serve the northern portion of the County. There were also elevated ILI rates in the northern districts when compared to the Rockford Public School District. This is visible in Figure 5.14, below. Figure 5.14 There is a distinct peak at week 41 for the northern school districts, while the peak is during week 43 for the Rockford Public School District. This data mirrors ILI activity in the northern portion of the county as well H1N1 Influenza Summary Report June 2010, Page 14

15 VI. Cases To date, Winnebago County has reported 234 confirmed cases of H1N1, resulting in 161 hospitalizations and contributing to 5 deaths. The range in ages varied, from one month to 85 years, with the average being years (median 20.5). The majority of cases were female (55%). The most common age group of all cases was the 5-17 group, followed by the group. Figure 6.01, below, shows more detail on age range and percent of overall cases. The rate of cases per 100,000 population is included in the far-right column. Age Range Total Cases n / % Rate / 19% / 26% / 23% / 24% / 8% Total 234 / 100% Figure 6.01 Age Range Mean Median 1 mo - 85 yrs yrs 20.5 yrs Figure 6.02, left. The age range, mean and median for all H1N1 cases in Winnebago County. Figure 6.03, right. The gender breakdown of all H1N1 cases in Winnebago County. Gender N % Male % Female % Figure 6.04, at left, shows the age profile for all H1N1 cases in Winnebago County. Forty-five percent of all cases were under the age of H1N1 Influenza Summary Report June 2010, Page 15

16 As with national trends, there were several co-morbidities present in cases of H1N1 in Winnebago County. The most common co-morbidity was that of asthma (29.5%), followed by diabetes (13.0%). In addition, 2.4% of all H1N1 cases were pregnant. Race Total Cases n / % Rate* White 152 / 64.9% African American/ Black 64 / 27.4% Other 18 / 7.7% Total 234 / 100% Figure 6.05 Ethnicity Total Cases n / % Rate* Hispanic 41 / 26.9% Non-Hispanic White 111 / 73.1% Total 152 / 100% Figure 6.06 The above charts show the dispersal of H1N1 cases by Race (Figure 6.05) and Ethnicity (6.06), respectively. *- Rate of cases per 100,000 population. Below is the epi-curve of the positive H1N1 cases by date of onset of illness. It is fairly visible, the two peaks, the first around week 21 and the second around week 42. The overlay is of deaths attributable to H1N1. Figure H1N1 Influenza Summary Report June 2010, Page 16

17 Figure 6.08, below, shows the spatial distribution by zip code of all H1N1 cases as a rate per 100,000 population. Figure All calculations in Figure 6.08 are as a rate per 100,000 population 2009 H1N1 Influenza Summary Report June 2010, Page 17

18 The Figure 6.08 shows higher rates of H1N1 in areas that are more highly populated, with the highest rate being in zip code Several surrounding zip codes were also fairly high. Surprisingly, in the areas north of the city, where the first H1N1 cases were identified, there are lower rates of H1N1. This may be due to underreporting or lack of severe symptomology, as after July 24, only hospitalized cases and those who accessed care from sentinel sites were reported. In addition, CDC recommendations stated that patients who felt ill should refrain from seeing their physician and stay home and self-treat. When looking at the H1N1 picture by period, the picture of the scope of the disease becomes clearer. Figures 6.09 and 6.10 are age distributions for H1N1 during Wave 1 and Wave 2, respectively. Of interest, Wave 1 shows the majority of cases were in those under the age of 17, but during Wave 2, the majority was over the age of 18. Figure 6.09 Figure 6.10 For more detail regarding H1N1 cases, refer to Appendix B H1N1 Influenza Summary Report June 2010, Page 18

19 VII. Hospitalizations Winnebago County has seen 161 H1N1 related hospitalizations to date. As with the overall case reporting, the age range for hospitalized cases was wide (1 month to 85 years). The average age increased to years from in all cases (median 37.5, previously 20.5). The majority of hospitalizations were female (53%). The most common age groups were 45-64, followed by More detail on age range and percent of overall cases is available in Figure 6.01, seen below. The rate of hospitalizations per 100,000 population is included in the far-right column. Age Range Total Hospitalizations n / % Rate / 17% / 17% / 24% / 31% / 11% Total 161 / 100% Age Range Mean Median 1 mo - 85 yrs yrs 37.5 yrs Figure 6.01 Figure 6.02, left. The age range, mean and median for all hospitalized H1N1 cases in Winnebago County. Figure 6.03, right. The gender breakdown of all hospitalized H1N1 cases in Winnebago County. Gender N % Male 75 47% Female 86 53% Figure 6.04, at left, shows the age profile for all hospitalized H1N1 cases in Winnebago County. Thirty-Four percent of all cases were under the age of H1N1 Influenza Summary Report June 2010, Page 19

20 Co-morbidity incidence in all hospitalized cases of H1N1 show elevated rates of asthma (34.1%) and diabetes (16.4%), in addition to the 8.2% of hospitalized cases who were found to be immunocompromised. In addition, 33.5% of those hospitalized were diagnosed with pneumonia, either viral or bacterial. Race Total Hospitalizations n / % Rate* White 107 / 66.5% African American/ Black 40 / 24.8% Other 14 / 8.7% Total 161 / 100% Ethnicity Total Hospitalizations n / % Rate* Hispanic 24 / 22.4% Non-Hispanic White 83 / 77.6% Total 107 / 100% Figure 6.05 Figure 6.06 The charts above show the distribution of H1N1 hospitalizations by Race (Figure 6.05) and Ethnicity (Figure 6.06), respectively (*- Rate of cases per 100,000 population). Two-thirds of cases were reported to be white, while the remaining third were among people of color. Additionally, nearly 15% reported themselves being of Hispanic origin. The epi-curve, as seen below, shows the positive H1N1 hospitalizations by reported date of onset of illness. While the first peak is small, the second wave is clearly visible. The overlay is of deaths attributable to H1N1. Four out of the five deaths occurred during the second wave. Figure H1N1 Influenza Summary Report June 2010, Page 20

21 The spatial distribution by zip code of all hospitalized cases in seen below in Figure All rates are shown as cases per 100,000 population All calculations in Figure 6.08 are as a rate per 100,000 population 2009 H1N1 Influenza Summary Report June 2010, Page 21

22 The data in this figure mirrors the data from the total case rate figure. The highest rates of hospitalized cases were within the zip codes and (both within the City of Rockford), with a reduced rate of positive cases in the Western half of the county. When isolating just Wave 1 and Wave 2, it is clear to see the difference in ages hospitalized for the two separate times. Figures 6.09 and 6.10 show this disparity. While in Wave 1, those under the age of 18 make up over half the reported hospitalizations, in Wave 2 they account for only a third of those reported as hospitalized. Figure 6.09 Figure 6.10 For more detail regarding H1N1 hospitalizations, refer to Appendix C H1N1 Influenza Summary Report June 2010, Page 22

23 VII. Percent of Hospitalizations Higher hospitalization percentages were present in the older age groups. This is attributed to other infections and co-morbidities that are more prevalent in older populations. Figure 7.01, below, shows the percent of cases hospitalized by age. Figure 7.01 Age Range Total Cases Total Hospitalizations % Hospitalized % % % % % Total % Figure 7.02, below, shows the difference in percentage of hospitalization by gender. There is only a minor difference in the data between females and males. Gender Total Cases Total Hospitalizations % Hospitalized Female % Male % Total % Figure H1N1 Influenza Summary Report June 2010, Page 23

24 The percentage of hospitalizations was lower for African Americans than for other races, but by ethnicity, the percentage for Hispanics was much lower than that for Non- Hispanic whites. This is seen in Figures 7.03 and Race Total Cases Total Hospitalizations % Hospitalized White % African American/ Black % Other % Total % Figure 7.03 Ethnicity Total Cases Total Hospitalizations % Hospitalized Hispanic % Non-Hispanic White % Total % Figure 7.04 When comparing by wave, there is a large discrepancy in the percentage of hospitalizations. During Wave 1, the hospitalization percentage was 17%, while it was 85% in Wave 2. This can largely be explained by the CDC guidance on July 24, 2009 that stated to only test hospitalized cases for H1N1 (3). Further representations of hospitalization percentages by wave can be found in Appendix D H1N1 Influenza Summary Report June 2010, Page 24

25 IX. Laboratory Submissions In order to confirm an H1N1 diagnosis, a sample from the patient must be submitted for testing. Early in the outbreak, all samples nationwide were sent to the CDC laboratories, but as the outbreak grew in scale, state laboratories quickly became the primary way to test for H1N1. Overall, Winnebago County submitted 1688 samples for testing from April 2009 through February 27, One-thousand, three-hundred sixty-nine samples were submitted on behalf of residents of the county, while the other 319 were from persons who resided outside the county. Below, in Figure 8.01, is a graph showing the amount of specimens submitted, with the percentage of positive specimens overlaid. The percent positive line is the number of positive submissions divided by the number of overall submissions. The week with the most submissions was week 43 (92 submissions), while week 23 had the highest percentage of positive submissions (5 out of 8 for 62.5% positive). This number is likely influenced by the CDC protocol at the time that was limiting the numbers of submissions permitted to be tested H1N1 Influenza Summary Report June 2010, Page 25

26 X. Projected Estimates of Actual H1N1 Spread Given that only hospitalized cases were tested for H1N1 during the majority of the pandemic, the CDC developed a procedure to estimate the number of H1N1 cases based on the number of hospitalized cases (7). According to Reed et al., the estimated number of H1N1 cases are drastically underreported when compared to the actual numbers of H1N1 cases in the population (7). To calculate the number of H1N1 hospitalizations, reported hospitalization numbers from April to December 12, 2009, were entered in to an equation that takes in to account non-reported cases, non-tested cases and cases that may have received a false negative. This calculated value was also used to determine the number of cases and number of deaths attributable to H1N1. Figure 9.01, seen on page 27, shows the calculated estimates of cases, hospitalizations and deaths for Winnebago County H1N1 Influenza Summary Report June 2010, Page 26

27 2009 H1N1 Projections Mid-Level Range Estimated Range Cases 0-4 Years 16,169 11,480 to 23, Years 16,169 11,480 to 23, Years 6,587 4,677 to 9, Years 23,953 10,077 to 35, Years 22,756 16,157 to 33, Years and Older 10,779 7,653 to 15,845 Cases Total 96,412 68,453 to 141,726 Hospitalizations 0-4 Years to Years to Years to Years to Years to Years and Older to 71 Hospitalizations Total to 639 Deaths 0-4 Years to Years to Years to Years to Years to Years and Older to 4.3 Deaths Total to 38.3 Figure 9.01 Figure Projections of H1N1 spread within Winnebago County H1N1 Influenza Summary Report June 2010, Page 27

28 Rates were calculated for the State of Illinois and the United States for comparison. These comparisons are seen in Figures 9.02 and 9.03, respectively. Rates per 100,000 population were calculated to use as a comparative tool between jurisdictions. Age Range Winnebago Winnebago Illinois Illinois Percent Estimate Rate* Estimate Rate* Difference ,168 78, ,835 32, % ,168 27, ,329 13, % ,587 30, ,970 10, % ,953 22, ,247 8, % ,756 42, ,905 11, % ,779 27, ,598 6, % Total 96,412 32,110 1,495,885 11, % Figure 9.02 Age Range Winnebago Winnebago United States United States Percent Estimate Rate* Estimate Rate* Difference ,337 43,331 17,608,657 23,814 82% ,629 31,904,109 16,682 72% ,779 27,346 4,982,542 12, % Total 96,412 32,110 54,495,308 17,923 78% Figure H1N1 Influenza Summary Report June 2010, Page 28

29 XI. Vaccine Coverage Beginning in early October, the CDC began shipping H1N1 vaccine to states, based on population (8). Vaccine supply delivered to the Winnebago County Health Department was disseminated through the Illinois Department of Public Health. There are 2 kinds of H1N1 vaccine: The flu shot, which is an inactivated vaccine, and the nasal spray, an attenuated virus. Winnebago County began to receive shipments of H1N1 vaccine very slowly, starting the week of October 19, late in Wave 2. In order to vaccinate as many people as possible, the Winnebago County Health Department worked closely with its community partners through clinics, media relations and vaccine distribution. Below is Figure This figure shows the cumulative amounts of vaccine received by the Winnebago County Health Department, the amount of vaccinations administered by the health department, and the number of vaccines shared with community partners. Figure H1N1 Influenza Summary Report June 2010, Page 29

30 Other community partners assisted in the vaccination of the Winnebago County population, such as hospital systems, pharmacies and private providers. Below, in Figures and 10.03, is the distribution of vaccine received and vaccine administered by provider type. Overall, 116,000 vaccines were received and 57,023 (49.15%) were administered. Figure Figure When the vaccine began to arrive at the Winnebago County Health Department, the CDC designated prioritization of vaccine delivery to high risk groups. Those under the age of 24, pregnant women and those aged with any of the following conditions; asthma, COPD, heart disease and diabetes were considered high risk (9). Clinics were set up at various areas to target these populations, in addition to clinics that visited county schools and daycare centers. Overall, just over 36,000 vaccines were administered to children in local schools (37.6% of overall enrollment). In those aged six months to nine years, two doses of the 2009 H1N1 Influenza Summary Report June 2010, Page 30

31 vaccine were required. Of those children in that group who received the first shot, 86% completed the series. Similar results were seen in daycares, with 2,020 vaccinations administered (36.9% of overall enrollment), and 74% completing the two-dose series. These numbers may be lower than the actual outcome as many parents elected to attend one of the community clinics in lieu of the school vaccination program. Overall, the WCHD delivered 246 clinics to area schools, daycares, community appointment clinics and other private enterprise clinics. Through these clinics, over 46,000 vaccine doses were administered. This value includes second doses for those who required the second dose. Figure goes in to more detail about the type of clinic delivered to selected groups. Clinic Type Number of Clinics Vaccines Administered Schools* ,185 Daycares 26 2,020 Community Appointments Other (Worksite, private, etc.) 70 8, ,201 TOTAL ,127 Figure *includes second-dose clinics includes second doses 2009 H1N1 Influenza Summary Report June 2010, Page 31

32 Figure Figure shows the number of confirmed H1N1 cases compared to dates to when vaccine supplies were available in the County. Vaccine did not arrive until week 41, and high enough amounts to begin mass-vaccination clinics were not received until week 46. This was similar to the trend in other areas in the country due to issues in the manufacturing of the vaccine and late distribution as a result H1N1 Influenza Summary Report June 2010, Page 32

33 XII. Media Coverage When the first confirmed cases of H1N1 were confirmed, the Winnebago County Health Department Media division began generating news releases, conducting interviews with local television and newspaper, holding press conferences, giving presentations and administering Public Service Announcements and commercials for radio and television. In total, there were over 1,600 media impressions from April 2009 to February In addition, signs were placed at both the Cherry Vale Mall and at the Chicago-Rockford International Airport. Signs and handouts were also made available at the entrances of all health facilities within the County. The below figure (12.01) shows the number of selected media inquiries by week with an overlay of confirmed H1N1 cases. Figure There were significant associations between confirmed H1N1 cases and presentations given and television media impressions. There were also numerous radio advertisements, both paid and free PSA s H1N1 Influenza Summary Report June 2010, Page 33

34 Figure 12.02, below, shows the number of cumulative radio impressions. There were both paid advertisements and free Public Service Announcements (PSA s) that were delivered on numerous radio stations, beginning in week 45. Figure The use of social media networks, such as Facebook, Twitter and website updates were also frequently utilized throughout the duration of the pandemic. Before the pandemic began, the website was averaging 800 visits a week, but during the first wave, those visits increased to over 1,800 visits a week. During the second wave, the weekly average remained high, at just over 1,900 visits. There was a direct association between website visits and Emergency Department visits (Figure 12.03), website hits and a confirmed H1N1 case (Figure 12.04), and website hits and overall media impressions (Figure 12.05) H1N1 Influenza Summary Report June 2010, Page 34

35 Figure Figure H1N1 Influenza Summary Report June 2010, Page 35

36 Figure During the first wave and latent period of the H1N1 pandemic, the majority of media coverage was designed around the three C s (Cover, Clean, Contain) and other preventative measures to limit the number of H1N1 cases. Once vaccine became available, the coverage began to shift to begin the mass vaccination campaign. From October 18, 2009 to February 27, 2010, there were a combined 32,109 impressions, including website hits and advertisements. This was also the time when new signs were placed at Cherry Vale Mall and the Chicago- Rockford International airport, along with on Rockford Mass Transit District buses. In Figure 12.06, below, the association between the media push and increased vaccination amounts (r-score, 0.969) is visible. Figure H1N1 Influenza Summary Report June 2010, Page 36

37 XIII. Discussion From April 26, 2009 to February 27, 2010, Winnebago County experienced 234 H1N1 related illnesses, 161 H1N1 related hospitalizations and five H1N1 related deaths. Surveillance activities through sentinel reports, laboratory confirmations, school absenteeism reporting and influenza-like illness reporting made monitoring the trends of H1N1 more streamlined than if they were not available. Through ILI monitoring, trends of sickness were visible, both within the County and region-wide. Locally, there were large increases in activity in those under the age of 18, with data peaking between Weeks 42 (0-4 ILI, 29.1% of total visits) and 43 (5-17 ILI, 34.9% of total visits). This data mirrors the large increases in school absenteeism data. Jurisdictionally, Winnebago County saw increased levels of ILI activity compared to much of the Chicago region, with the exception of Kane County (see Figure 5.03, page 8). The peak of ILI activity occurred at the same time for all 5 comparative jurisdictions (Week 43). Overall, the higher rate of cases were in the younger populations at the beginning of the pandemic, but as the pandemic progressed, those who were older were at more risk to develop complications. This data mirrors both state and national trends. For hospitalized cases, more were 18 years and over, rather than under the age of 18. That trend is reflected in the rate per 100,000 population (see Figure 6.01, page 19). While the higher number of cases was in those under 18 years old, 93% of all cases over the age of 45 were hospitalized (see Figure 7.01, page 23). This is due in part to the higher number of co-morbidities, such as asthma and diabetes, present in the older populations. Overall, 69% of all cases were hospitalized, but after July 24, only hospitalized cases for ILI and suspect cases from select sentinel sites were tested for H1N1. Projection extrapolation and analysis was a very useful tool to analyze the possible spread of H1N1 across a jurisdiction, since most cases may seek medical care or be tested for H1N1. Overall, the projected H1N1 impact in Winnebago County from April to December 12, 2009 is 32,110 cases per 100,000 population (96,412 median projected cases). This figure is 177% higher than the Illinois rate (11,595 per 100,000) and is 78% the National Average (17,923 per 100,000). It is believed that higher hospitalization rates and greater access to care may have an impact on the large increases in rate. Providing vaccine to all community members was a large focus of the Winnebago County Health Department. In forming a public-private partnership, over 57,000 vaccinations 2009 H1N1 Influenza Summary Report June 2010, Page 37

38 were administered (as of February 27, 2010). Clinics were provided by the Health Department, private physicians and medical centers, in addition to various private workplaces and pharmacies. Vaccination clinics were largely driven by media coverage that was designed to spread the word about vaccinations. The high r-score (0.969) demonstrates that the media impressions and website usage were helpful in encouraging people to get vaccinations. There were various strengths to the Winnebago County H1N1 response. Previous pandemic influenza plans aided in the preparation for the 2009 H1N1 pandemic, as well as opening the communication channels with partner agencies around the County. Cooperation from these partners allowed resources to be utilized in the best possible way, maximizing the H1N1 response. New methods to reach the community, such as the health department webpage, Facebook and Twitter proved effective in generating an appropriate response to either prevention of H1N1 or vaccination for H1N1. There were also limitations discovered during the H1N1 pandemic period. First, the pandemic was widespread when it was recognized in the population, and differentiation between H1N1 and seasonal influenza proved a challenge, particularly early in the pandemic (April, May and June). Vaccine production technology is aged, but capacity was expanded to meet increased demand. Finally, due to grant funding limitations, surge capacity, most notably at local Emergency Departments, was severely challenged. Lessons learned from the 2009 H1N1 pandemic are essentially important in the improvement of local pandemic bioagent and all-hazards response plans. Currently, planning exercises are being developed using lessons learned from the 2009 H1N1 pandemic. Surveillance methods are being streamlined and made more effective to monitor both H1N1 and seasonal influenza, but other potential bioagents in the community. In conclusion, the efforts asserted by the Winnebago County Health Department and its community partners were beneficial in reducing the impact of the 2009 H1N1 influenza pandemic. Surveillance efforts are still currently monitoring the state of the 2009 H1N1 influenza within the county, and vaccination clinics are still being held. This report will continue to be updated as data becomes available H1N1 Influenza Summary Report June 2010, Page 38

39 XIV. Acknowledgments It must be recognized that a great deal of compilation and analysis of data was necessary to develop this report. Its principal author is Zachary McCormic, Epidemiologist for the Winnebago County Department of Public Health. This report was reviewed and critiqued by Kara McCluskey, Communicable Disease Supervisor and Dee Dunnett, Health Promotion and Protection Center Director, as well as by Administration, prior to its posting. The Winnebago County Department of Public Health also wishes to recognize each of our staff for their flexibility and contribution for protecting the health of Rockford and Winnebago County residents during the H1N1 Influenza Pandemic. Their willingness to cover the routine responsibilities of others or to be directly involved in the prolonged and intense pandemic response was fundamental to our Department s ability to cope with this rare public health threat. The Winnebago County Department of Public Health would like to thank all the public and private community partners, consortium members and volunteers who during this past year provided exemplary services so essential to protecting the health of this Community over the course of this Pandemic. Collectively these efforts have led to achieving the pandemic response strategic goals to 1.) limit death and suffering through proper preventive, curative and supportive care to those most vulnerable, 2.) aid in the application of the least restrictive interventions to contain the disease threat and 3.) contribute to the economic and financial stability of the community during a pandemic that infected almost estimated one-third of our community s residents. Our appreciation must be expressed to that of the local popular media including newspapers, television stations and radio stations for their support of the key messages so essential to keeping the public accurately informed. And finally, the general public must be recognized for their adherence to the recommendations provided and for their understanding and patience in accessing educational and vaccination services throughout the course of this Pandemic. Public Health is often defined as what we do collectively to assure conditions in which our residents can be healthy. The H1N1 Influenza Pandemic response exemplifies the spirit of our community s commitment to public health practices and principles H1N1 Influenza Summary Report June 2010, Page 39

40 XV. Works Cited 1. CDC. (2009). Swine influenza a (H1N1) infection in two children---southern California, March--April MMWR 2009, 58. Retrieved from mmwrhtml/mm58d0421a1.htm 2. CDC. (2009). Update: infections with a swine-origin influenza a (H1N1) virus---united States and other countries, April 28, MMWR 2009, 58(16), Retrieved from Centers for Disease Control and Prevention. (2009, October 27) H1N1 early outbreak and disease characteristics. Retrieved from 4. CDC. (2009) Pandemic influenza a (H1N1) virus infections---chicago, Illinois, April --July MMWR 2009, 58(33), Retrieved from mmwrhtml/mm5833a1.htm 5. Kinnikinnick schools to reopen. (2009, May 6). Rockford Register Star. 6. Westphal, M. (2009, October 29). South Beloit cancels classes today. Rockford Register Star. 7. Reed, C., Angulo, F.J., Swerdlow, D.L., Lipsitch, M., Meltze, M.I., Jernigan, D., et al. Estimates of the prevalence of pandemic (H1N1) 2009, United States, April-July Emerg Infect Dis [serial on the internet] Dec; [Epub ahead of print] 8. Centers for Disease Control and Prevention. (2010, February 5). Facts about the 2009 H1N1 vaccine. Retrieved from vaccine_keyfacts.htm 9. Centers for Disease Control and Prevention. (2009, November 10). People at high risk of developing flu-related complications. Retrieved from highrisk.htm 2009 H1N1 Influenza Summary Report June 2010, Page 40

41 XVI. Additional Tables A. Appendix A Page - 42 B. Appendix B Page - 52 C. Appendix C Page - 59 D. Appendix D Page H1N1 Influenza Summary Report June 2010, Page 41

42 Appendix A Influenza-Like Illness * Section 1: ILI Activity by Age Winnebago County versus Regional data, by age Please note, increases in ILI activity from weeks 1 through 8 of 2010 are attributable to high levels of RSV, not H1N1. *-All data analyzed via ESSENCE (Electronic Surveillance System for the Early Notification of Community based Epidemics) 2009 H1N1 Influenza Summary Report June 2010, Page 42

43 Winnebago County versus Regional data, by age, continued Winnebago County versus other Jurisdiction data, by age 2009 H1N1 Influenza Summary Report June 2010, Page 43

44 Winnebago County versus other Jurisdiction data, by age, continued Section 2: ILI Activity by Period Winnebago County versus other Jurisdiction data, by period 2009 H1N1 Influenza Summary Report June 2010, Page 44

45 Winnebago County versus other Jurisdiction data, by period, continued Please note, increases in ILI activity from weeks 1 through 8 of 2010 are attributable to high levels of RSV, not H1N H1N1 Influenza Summary Report June 2010, Page 45

46 Section 3: ILI Activity by Wave Wave 1: April 21-June 6, H1N1 Influenza Summary Report June 2010, Page 46

47 Wave 1: April 21-June 6, 2009, continued Latent Period: June 6-August 29, H1N1 Influenza Summary Report June 2010, Page 47

48 Latent Period: June 6-August 29, 2009, continued Wave 2: August 30-December 12, H1N1 Influenza Summary Report June 2010, Page 48

49 Wave 2: August 30-December 12, 2009, continued 2009 H1N1 Influenza Summary Report June 2010, Page 49

50 Post-Wave Period: December 13, 2009-February 27, 2010 Please note, increases in ILI activity from weeks 1 through 8 of 2010 are attributable to high levels of RSV, and not H1N H1N1 Influenza Summary Report June 2010, Page 50

51 Post-Wave Period: December 13, 2009-February 27, 2010, continued 2009 H1N1 Influenza Summary Report June 2010, Page 51

52 Appendix B: Confirmed H1N1 Cases Section 1: Wave 1 - April 21-June 6, 2009 Figure B.1.01, above. Dispersal of H1N1 cases by age for Wave 1. The majority of cases are in those aged 17 and under. Figure B.1.02, right. Age range for all confirmed H1N1 cases during the first wave period. Included are case counts and percentage of overall cases per age group. * - Rate per 100,000 population Age Range Total Cases Rate* / 17% / 52% / 17% / 14% / 0% 0 Total 52 / 100% Age Range Mean Median 2 mo - 61 yrs yrs 10.5 yrs Figure B.1.03, left. Age range, mean and median of all Wave 1 cases. Figure B.1.04, right. The slight majority of cases were female (54%) during the first wave. Gender N % Female 28 54% Male 24 46% 2009 H1N1 Influenza Summary Report June 2010, Page 52

53 Race Total Cases n / % Rate* White 37 / 71% African American/ Black 15 / 29% Other 0 / 0% 0 Total 52 / 100% Figure B.1.05, left. Racial distribution of all Wave 1 H1N1 cases. The majority identified themselves as White. * - Rate per 100,000 Ethnicity Total Cases n / % Rate* Hispanic 17 / 45.9% Non-Hispanic White 20 / 54.1% 8.90 Total 37 / 100% Figure B.1.06, above, shows the ethnic background of all cases. A slight majority of cases were Non-Hispanic. * - Rate per 100,000 population Figure B.1.07, above, shows the geographical distribution by zip code of the H1N1 cases during Wave 1. Rates are given per 100,000 population H1N1 Influenza Summary Report June 2010, Page 53

54 Section 2: Latent Period - June 7-August 29, 2009 Figure B.2.01, above. Dispersal of H1N1 cases by age for the Latent Period. The majority of cases are in those aged 17 and under. Age Range Total Cases n / % Rate* / 50% / 10% / 30% / 10% / 0% 0 Total 10 / 100% 3.33 Figure B.2.02, above. Age range for all confirmed H1N1 cases during the latent period. Included are case counts and percentage of overall cases per age group. * - Rate per 100,000 Age Range Mean Median 2 mo - 54 yrs yrs 8.0 yrs Figure B.2.03, above. Age range, mean and median of all latent period cases. Gender N % Female 6 60% Male 4 40% Figure B.2.04, left. The slight majority of cases were female (60%) during the latent period H1N1 Influenza Summary Report June 2010, Page 54

55 Race Total Cases n / % Rate* White 5 / 50% 1.95 African American/ Black 4 / 40% Other 1 / 10% Total 10 / 100% 3.33 Figure B.2.05, left. Racial distribution of all Wave 1 H1N1 cases. The majority identified themselves as White. * - Rate per 100,000 Ethnicity Total Cases n / % Rate* Hispanic 0 / 0% 0.00 Non-Hispanic White 5 / 100% 2.22 Total 5 / 100% 1.95 Figure B.2.06, above, shows the ethnic background of all cases. All cases were reported as Non-Hispanic. * - Rate per 100, Figure B.2.07, above, shows the geographical distribution by zip code of the H1N1 cases during Wave 1. Rates are given per 100,000 population H1N1 Influenza Summary Report June 2010, Page 55

56 Section 3: Wave 2 - August 30-December 12, 2009 Figure B.3.01, above. Dispersal of H1N1 cases by age for Wave 2. The majority of cases are in those over the age of 18. Age Range Total Cases n / % Rate* / 18% / 20% / 24% / 27% / 11% Total 171 / 100% Figure B.3.02, above. Age range for all confirmed H1N1 cases during the second wave period. Included are case counts and percentage of overall cases per age group. * - Rate per 100,000 population Figure B.3.03, below. Age range, mean and median of all Wave 2 cases. Age Range Mean Median 1 mo - 85 yrs yrs 28.0 yrs Figure B.3.04, right. The slight majority of cases were female (55%) during the second wave. Gender N % Female 94 55% Male 77 45% 2009 H1N1 Influenza Summary Report June 2010, Page 56

57 Race Total Cases n / % Rate* White 109 / 64% African American/ Black 45 / 26% Other 17 / 10% Total 171 / 100% Figure B.3.05, left. Racial distribution of all Wave 2 H1N1 cases. The majority identified themselves as White. * - Rate per 100,000 population Ethnicity Total Cases n / % Rate* Hispanic 24 / 28.2% Non-Hispanic White 85 / 71.8% Total 109 / 100% Figure B.3.06, right, shows the ethnic background of all cases. The majority of cases were Non-Hispanic. * - Rate per 100,000 population Figure B.3.07, above, shows the geographical distribution by zip code of the H1N1 cases during Wave 2. Rates are given per 100,000 population 2009 H1N1 Influenza Summary Report June 2010, Page 57

58 Section 4: Post-Wave Period - December 13, 2009-February 27, 2010 Due to a significantly reduced number of cases during the post-wave period, data has been excluded from publication H1N1 Influenza Summary Report June 2010, Page 58

59 Appendix C: Hospitalized H1N1 Cases Section 1: Wave 1 - April 21-June 6, 2009 Figure C.1.01, above. Dispersal of H1N1 hospitalizations by age for Wave 1. The majority of cases are in those aged 17 and under. Age Range Total Hospitalizations Rate* / 22% / 34% / 22% / 22% / 0% 0 Total 9 / 100% 2.99 Figure C.1.03, below. Age range, mean and median of all Wave 1 hospitalizations. Age Range Mean Median 2 mo - 49 yrs yrs 12.0 yrs Figure C.1.02, above. Age range for all confirmed H1N1 hospitalizations during the first wave period. Included are case counts and percentage of overall cases per age group. * - Rate per 100,000 population Gender N % Female 3 33% Male 6 67% Figure C.1.04, left. The majority of hospitalizations were male (67%) during the first wave H1N1 Influenza Summary Report June 2010, Page 59

60 Race Total Hospitalizations Rate* White 5 / 71% 1.95 African American/ Black 4 / 29% Other 0 / 0% 0 Total 9 / 100% 2.99 Figure C.1.05, above. Racial distribution of all Wave 1 H1N1 hospitalizations. The majority identified themselves as White. * - Rate per 100,000 population Figure C.1.06, below, shows the ethnic background of all hospitalized cases. The majority of cases were Non-Hispanic. * - Rate per 100,000 population Ethnicity Total Hospitalizations Rate* Hispanic 2 / 40% 6.43 Non-Hispanic White 3 / 60% 1.33 Total 5 / 100% Figure C.1.07, above, shows the geographical distribution by zip code of the H1N1 hospitalizations during Wave 1. Rates are given per 100,000 population H1N1 Influenza Summary Report June 2010, Page 60

61 Section 2: Latent Period - June 7-August 29, 2009 Figure C.2.01, above. Dispersal of H1N1 hospitalizations by age for the Latent Period. The majority of cases are in those aged 17 and under. Age Range Total Hospitalizations n / % Rate* / 40% / 0% / 40% / 20% / 0% 0 Total 5 / 100% 1.67 Figure C.2.03, below. Age range, mean and median of all latent period hospitalizations. Age Range Mean Median 6 mo - 54 yrs 20.9 yrs 22.0 yrs Figure C.2.02, above. Age range for all confirmed H1N1 hospitalizations during the latent period. Included are case counts and percentage of overall cases per age group. * - Rate per 100,000 population Figure C.2.04, right. The slight majority of hospitalizations were male (60%) during the latent period. Gender N % Female 2 40% Male 3 60% 2009 H1N1 Influenza Summary Report June 2010, Page 61

62 Race Total Hospitalizations Rate* White 3 / 60% 1.95 African American/ Black 1 / 20% Other 1 / 20% Total 5 / 100% 3.33 Figure C.2.05, above. Racial distribution of all Wave 1 H1N1 hospitalizations. The majority identified themselves as White. * - Rate per 100,000 population Figure C.2.06, below, shows the ethnic background of all hospitalized cases. All cases were reported as Non-Hispanic. * - Rate per 100,000 population Ethnicity Total Hospitalizations Rate* Hispanic 0 / 0% 0 Non-Hispanic White 3 / 100% 1.33 Total 3 / 100% Figure C.2.07, above, shows the geographical distribution by zip code of the H1N1 hospitalizations during Wave 1. Rates are given per 100,000 population H1N1 Influenza Summary Report June 2010, Page 62

63 Section 3: Wave 2 - August 30-December 12, 2009 Figure C.3.01, above. Dispersal of H1N1 hospitalizations by age for Wave 2. The majority of cases are in those over the age of 18. Age Range Total Hospitalizations n / % Rate* / 16% / 17% / 23% / 32% / 12% Total 146 / 100% Figure C.3.02, above. Age range for all confirmed H1N1 hospitalizations during the second wave period. Included are case counts and percentage of overall cases per age group. * - Rate per 100,000 population Figure C.3.03, below. Age range, mean and median of all Wave 2 hospitalizations. Age Range Mean Median 1 mo - 85 yrs yrs 39.5 yrs Gender N % Female 80 55% Male 66 45% Figure C.3.04, left. The slight majority of hospitalizations were female (55%) during the second Wave period H1N1 Influenza Summary Report June 2010, Page 63

64 Race Total Hospitalizations Rate* White 98 / 67% African American/ Black 35 / 24% Other 13 / 9% Total 146 / 100% Figure C.3.05, above. Racial distribution of all Wave 2 H1N1 hospitalizations. The majority identified themselves as White. * - Rate per 100,000 population Figure C.3.06, below, shows the ethnic background of all hospitalized cases. The majority of cases were Non-Hispanic. * - Rate per 100,000 population Ethnicity Total Hospitalizations Rate* Hispanic 22 / 22.4% Non-Hispanic White 76 / 77.6% Total 98 / 100% Figure C.3.07, above, shows the geographical distribution by zip code of the H1N1 hospitalizations during Wave 2. Rates are given per 100,000 population H1N1 Influenza Summary Report June 2010, Page 64