4.3.9 Pandemic Disease

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1 4.3.9 Pandemic Disease This section describes the location and extent, range of magnitude, past occurrence, future occurrence, and vulnerability assessment for the pandemic disease hazard for Armstrong County. Pandemics are large-scale disease outbreaks defined by the way a disease spreads rather than by the number of fatalities associated with the disease. A pandemic outbreak has several recognizable characteristics, including rapid, large-scale (potentially global) spread that causes overloaded healthcare systems; inadequate medical supplies; medical supply shortages; and a disrupted economy and society (Flu.gov 2015). Pandemics typically result from infectious diseases. An infectious disease, as defined by the World Health Organization (WHO), is caused by pathogenic organisms (e.g., bacteria, viruses, fungus, or parasites) that spread from one person to another, whether through direct or indirect contact. Zoonotic disease, a type of infectious disease, occurs when animals transmit a disease to humans (WHO 2015). Although any infectious disease can reach pandemic levels, influenza (flu) has the greatest likelihood of causing the next pandemic. The risk of a global influenza pandemic has increased over the last several years. This disease can claim thousands of lives and adversely affect critical infrastructure and key resources. An influenza pandemic has the ability to reduce the health, safety, and welfare of the essential services workforce; prevent core infrastructure from operating normally, such as hospitals (essential personnel becoming ill and unable to work); and induce fiscal instability. Pandemic influenza is different from seasonal influenza because pandemic influenza is caused by an influenza virus that is new to people (a novel virus) while seasonal influenza is caused by viruses that are already among people and to which many people have developed some forms of immunity. Pandemic influenza affects many more people than seasonal influenza. In addition, seasonal influenza occurs every year, usually during the winter season, while the timing of an influenza pandemic is difficult to predict. A severe pandemic could change daily life for a time, including limitations on travel and public gatherings (Barry-Eaton District Health Department 2013). At the national level, the Centers for Disease Control and Prevention s (CDC) Influenza Division has a long history of supporting the WHO and its global network of National Influenza Centers (NIC). With limited resources, most international assistance provided in the early years was through hands-on laboratory training of in-country staff, the annual provision of WHO reagent kits (produced and distributed by CDC), and technical consultations for vaccine strain selections. The Influenza Division also conducts epidemiologic research, including vaccine studies and serologic assays, and provides international outbreak investigation assistance (CDC 2011). Influenza most frequently spreads through the air or by touch; when an infected person coughs, infected droplets go into the air or onto their hands, facilitating transmission of the disease to other people (WHO 2015) Location and Extent Pandemic events cover a wide geographic area and can affect large populations, which can include multiple countries or continents. The size and extent of an infected population depends on how easily the illness is spread, mode of transmission, and amount of contact between infected and uninfected individuals. Locations with higher density populations are more susceptible to pandemic outbreaks, as the disease can be transmitted more easily. Additionally, vulnerable populations, especially the young and the elderly (who have weaker immune systems), are at greater risk for both contracting a disease and suffering fatal or severe consequences. When a pandemic or disease outbreak occurs, WHO and other public health institutions begin tracking the disease outbreak, treatment, and more. Ebola was a significant pandemic concern for American public health officials in 2014; however, the disease has primarily remained in Africa to date. Should a pandemic take hold Arnstrong County Hazard Mitigation Plan

in the United States, the Centers for Disease Control and Prevention (CDC) and the National Institutes of Health (NIH) would be actively involved in managing the outbreak and treatment of the disease.

2 in the United States, the Centers for Disease Control and Prevention (CDC) and the National Institutes of Health (NIH) would be actively involved in managing the outbreak and treatment of the disease. Although Ebola is still recognized as a global health threat, Armstrong County is primarily concerned with the possibility of a pandemic influenza outbreak. Influenza viruses with the potential to reach pandemic levels include the avian influenza A (H5N1) and avian influenza H7N9 (CDC 2015). In 2009, the swine influenza (H1N1) was of particular concern. H1N1 was first detected in people in the United States in April On June 11, 2009, WHO signaled that a pandemic of 2009 H1N1 influenza was underway (CDC 2009) Range of Magnitude The severity of a pandemic depends on a number of factors, as indicated above. These include aggressiveness of the disease, ease of transmission, and factors associated with the impacted community (e.g., access to medical care, demographic data, and population density). Advancements in medical technologies have greatly reduced the number of deaths caused by influenza, the disease most likely to reach pandemic scale in Pennsylvania. Consequently, global effects of various influenza outbreaks have declined over the past century. High-risk populations considered more vulnerable to various pandemic diseases are described in the vulnerability assessment. The CDC and Prevention Community Strategy for Pandemic Influenza Mitigation guidance introduced a Pandemic Severity Index (PSI), which uses the case fatality ratio as the critical driver for categorizing the severity of a pandemic. The index is designed to estimate the severity of a pandemic on a population to allow better forecasting of the impact of a pandemic, and to enable recommendations on the use of mitigation interventions that are matched to the severity of influenza pandemic. Pandemics are assigned to one of five discrete categories of increasing severity (Category 1 to Category 5) (CDC 2018). Figure illustrates the five categories of the PSI. Figure Pandemic Severity Index Source: CDC 2018 Arnstrong County Hazard Mitigation Plan

The WHO described a series of pandemic phases in 1999 and revised these in 2005 and 2009 to provide a global framework and aid in pandemic preparedness and response planning.

3 The WHO described a series of pandemic phases in 1999 and revised these in 2005 and 2009 to provide a global framework and aid in pandemic preparedness and response planning. In addition to facilitating implementation of preparedness recommendations, the phases also help provide greater understanding of when an event is considered to have reached pandemic levels. The six phases are shown on Figure below and are described as follows: Phase 1: No viruses circulating among animals have been reported among humans. Phase 2: An animal influenza virus circulating among domesticated or wild animals has caused known infection in humans and is now considered a potential pandemic threat. Phase 3: An animal or human-animal influenza reassortment virus has caused sporadic cases or small clusters of disease in people but has not resulted in human-to-human transmission sufficient to sustain community-level outbreaks. Limited human-to-human transmission may occur under some circumstances, such as close contact between an infected person and an unprotected caregiver. Phase 4: Verified human-to-human transmission of an animal or human-animal influenza reassortment virus is able to cause community-level outbreaks. The ability to cause sustained disease outbreaks in a community marks a significant upwards shift in the risk of a pandemic. Any country that suspects or has verified such an event should urgently consult with WHO so that the situation can be jointly assessed, and a decision made by the affected country if implementation of a rapid pandemic containment operation is warranted. Phase 4 indicates a significant increase in risk of a pandemic but does not necessarily mean that a pandemic is a forgone conclusion. Phase 5: There has been human-to-human spread of the virus into at least two countries in one WHO region. While most countries will not be affected at this stage, the declaration of Phase 5 is a strong signal that a pandemic is imminent, and that the time to finalize the organization, communication, and implementation of the planned mitigation measures is short. Phase 6: The pandemic phase is characterized by community-level outbreaks in at least one other country in a different WHO region, in addition to the criteria defined in Phase 5. Phase 6 indicates a global pandemic is underway. The conclusion of Phase 6 leads to the post-peak period, wherein pandemic levels decrease in most countries with surveillance capabilities. Despite a decrease in activity, countries still must be prepared for additional waves of the pandemic. Pandemic waves can be separated by a period of months, leading to a long recovery time to guarantee entry of the pandemic into the post-pandemic phase (WHO 2009). Figure Pandemic Influenza Phases Source: World Health Organization 2009 Arnstrong County Hazard Mitigation Plan

4 Pandemic influenza should not be confused with seasonal influenza. Seasonal influenza is a less severe concern because of its regularity of occurrence and predictability. Table lists key differences between pandemic influenza and seasonal influenza. Table Seasonal Influenza vs. Pandemic Influenza Pandemic Influenza Rarely happens (three times in 20th century). People have little or no immunity because they have no previous exposure to the virus. Healthy people may be at increased risk for serious complications. Healthcare providers and hospitals may be overwhelmed. Vaccine probably would not be available in the early stages of a pandemic. Effective antivirals may be in limited supply Number of deaths could be high (U.S. death toll during the 1918 pandemic was approximately 675,000). Symptoms may be more severe May cause major impact on the general public, such as widespread travel restrictions and school or business closings. Potential for severe impact on domestic and world economy. Source: Flu.gov 2015 Seasonal Influenza Happens annually and usually peaks in January or February. Usually some immunity built up from previous exposure. Usually only people at high risk, not healthy adults, are at risk of serious complications. Healthcare providers and hospitals can usually meet public and patient needs. Vaccine available for annual influenza season. Adequate supplies of antivirals are usually available. Seasonal influenza-associated deaths in the U.S. over 30 years ending in 2007 have ranged from about 3,000 per season to about 49,000 per season. Symptoms include fever, cough, runny nose, and muscle pain. Usually causes minor impact on the general public; some schools may close, and sick people are encouraged to stay home. Manageable impact on domestic and world economy Past Occurrence Several pandemic influenza outbreaks have occurred over the past 100 years. A list of worldwide pandemic events appears in Table Deaths occurred in the United States as a result of Spanish influenza, Asian influenza, and Hong Kong influenza outbreaks. Spanish influenza ( ) claimed 500,000 lives in the United States, with 350,000 cases reported in Pennsylvania. Most deaths resulting from Asian influenza occurred between September 1957 and March 1958; within the United States, approximately 70,000 people died, and approximately 15 percent of the population of Pennsylvania was affected. The first cases of Hong Kong influenza in the United States were detected in September 1968, with deaths peaking between December 1968 and January 1969 (Global Security, 2009). As of August 2010, H1N1 was in a post-pandemic period. Table Previous Pandemic Outbreaks Source: CDC 2010 Date Pandemic/Subtype Worldwide Deaths (Approx.) Spanish Flu/H1N1 50 Million Asian Flu/H2N Million Hong Kong Flu/H3N2 1 Million Swine Flu/H1N1 > 18,000 Epidemiologists and public health officials consistently track the rate of influenza or influenza-like illnesses (ILI) to monitor potential pandemic threats. This also allows them to provide annual data on ILI seasonal outbreaks. Figure below shows the biweekly national number of cases of ILI during the season, distinguishing each type of ILI by a unique color. Arnstrong County Hazard Mitigation Plan

Figure 4.3.9-3. ILI Cases in Pennsylvania, 2017 2018 Season Source: PA Department of Health 2017 The Pennsylvania Department of Health tracks positive influenza tests. Table 4.3.9-3 shows the numbers of positive ILI tests in Armstrong County in recent years.

5 Figure ILI Cases in Pennsylvania, Season Source: PA Department of Health 2017 The Pennsylvania Department of Health tracks positive influenza tests. Table shows the numbers of positive ILI tests in Armstrong County in recent years. Table Positive ILI tests in Armstrong County Year Influenza Type A Influenza Type B Influenza Type U Total 2005/2006 N/A N/A N/A /2007 N/A N/A N/A /2008 N/A N/A N/A /2009 N/A N/A N/A /2010 N/A N/A N/A /2011 N/A N/A N/A /2012 N/A N/A N/A /2013 N/A N/A N/A / / / / Arnstrong County Hazard Mitigation Plan

6 Year Influenza Type A Influenza Type B Influenza Type U Total 2017/ Source: PA Department of Health 2017 Note: Influenza type not available prior to 2013/ Future Occurrence Predicting the future occurrences of pandemics is difficult. Although any infectious disease can reach pandemic levels, influenza has the greatest likelihood of causing the next pandemic. Based on the history of occurrences in Armstrong County, it is likely that the County will be impacted by certain diseases in the future. Additionally, an increase in population and population density in Armstrong County may increase resident exposure and susceptibility to outbreaks. Infected mosquitos and ticks will continue to inhabit and impact Armstrong County. Based on previous occurrences of the various diseases, pandemics, and outbreaks of the different diseases will continue to occur. However, the future of these diseases and their impacts on Armstrong County is uncertain. Future pandemics may also emerge from other diseases, especially invasive pathogens to which residents of Armstrong County do not have natural immunity. In Section 4.4, the identified hazards of concern for Armstrong County were ranked for relative risk. The probability of occurrence, or likelihood of the event, is one parameter used for ranking hazards. Based on historical records and reference to the Pennsylvania State HMP, the probability of occurrence for pandemic events in Armstrong County is considered possible. Please refer to Section 4.4 for further information on the Pennsylvania Emergency Management Agency s (PEMA) risk factor methodology and the risk factors used to determine each hazard s risk rank Vulnerability Assessment To understand risk, a community must evaluate what assets are exposed and potentially vulnerable to the identified hazard. For the pandemic hazard, the entire County has been identified as the hazard area. Therefore, all assets (population, structures, critical facilities, and lifelines), as described in the Community Profile (Section 2), are exposed and potentially vulnerable. The following text evaluates and estimates the potential impact of a pandemic event on Armstrong County, including: Overview of vulnerability Data and methodology used for the evaluation Impact on: (1) life, health and safety, (2) general building stock, (3) critical facilities, (4) economy, (5) environment, and (6) future growth and development Effect of climate change on vulnerability Further data collections that will assist understanding of this hazard over time Overview of Vulnerability Depending on characteristics of the disease or virus, certain population groups can be at higher risk of infection than others. Regarding seasonal influenza, about 60 percent of hospitalizations and 90 percent of influenzarelated deaths occur among people 65 and older. However, during the H1N1 pandemic, 90 percent of hospitalizations and 87 percent of H1N1-related deaths occurred in people younger than 65. As with seasonal influenza, people with underlying health conditions faced a much higher probability of contracting H1N1. Schools, convalescent centers, and other institutions are highly conducive to faster transmission of pandemic diseases (CDC 2010). Arnstrong County Hazard Mitigation Plan

7 Data and Methodology A qualitative assessment was conducted to evaluate the assets exposed and the potential impacts associated with this hazard. Impact on Life, Health, and Safety The entire population of Armstrong County is vulnerable to a pandemic event. According to the 2016 American Community Survey 5-Year Population Estimate, the County s population was 67,512. The elderly population and individuals with suppressed immune systems may be more susceptible to effects of diseases such as influenza. Table shows the demographic change in children and the elderly from 2000 through There are fewer individuals under 65 years of age, but more individuals over 65 years of age in the County. Therefore, Armstrong County is more vulnerable to seasonal influenza but less vulnerable to pandemic influenza such as the H1N1 pandemic. Table Demographic Trends for Vulnerable Populations Vulnerable Population Children under 5 years 2000 Census 2010 Census 2016 Census Estimate 2000 to 2016 Change 3,913 3,605 3, Under 18 years 16,574 14,189 13,204-3, years and over 13,053 12,687 13, Source: U.S. Census Bureau 2017 Impact on General Building Stock and Critical Facilities No structures are anticipated to be directly affected by a pandemic event. Impact on the Economy The impact pandemic events can have on the economy and estimated dollar losses are difficult to measure and quantify because the exact rates of absenteeism and costs of treating widespread disease will depend on the virus or bacterium in question, the availability of vaccinations or treatments, and the severity of symptoms. Costs associated with the activities and programs implemented to conduct surveillance and address pandemic events have not been quantified in available documentation. Widespread illness may increase the likelihood of shortages of personnel to perform essential community services. In addition, high rates of illness and worker absenteeism occur within the business community, and these contribute to social and economic disruption. Social and economic disruptions could be temporary but may be amplified in today s closely interrelated and interdependent systems of trade and commerce. Social disruption may be greatest when rates of absenteeism impair essential services, such as power, transportation, and communications (PEMA 2018). Impact on the Environment There are no true environmental impacts of pandemic and infectious disease threats, but there will be significant economic and social costs beyond the possibility of disease-related death (see the Impact on the Economy subsection) (PEMA 2018). However, there are environmental factors that can influence the spread of diseases that are prone to lead to pandemics. These include: water supply, sanitation facilities, food, and climate. A lack of safe water, inadequate sanitation facilities, poor hygiene, and unsafe food can all lead to additional impacts to those already suffering. Climate can affect disease transmission in numerous ways. The distribution and Arnstrong County Hazard Mitigation Plan

8 population size of disease vectors can be heavily affected by local climate. Flooding after heavy rains can result in sewage overflow and widespread water contamination leading to illness (WHO 2018). Future Growth and Development Areas targeted for potential future growth and development in the next five to ten years have been identified across Armstrong County (further discussed in Section 4.4 of this HMP). It is anticipated that any new development and new residents will be exposed to the pandemic hazard. Effect of Climate Change on Vulnerability An increase in temperature and humidity may lead to a larger number of influenza outbreaks. Studies have shown that warmer winters led to an increase in influenza cases. During warm winters, fewer people contract influenza, causing many people to remain vulnerable into the next season and leading to an early and strong occurrence of the virus (Spross 2013). Additional Data and Next Steps For the HMP update, any additional information regarding localized concerns and past impacts will be collected and analyzed. This data will be developed to support future revisions to the plan. Future mitigation efforts could include building on existing Pennsylvania, Armstrong County, and local efforts. Arnstrong County Hazard Mitigation Plan

5.4.8 Pandemic Disease

5.4.8 Pandemic Disease The following section provides the hazard profile (description, location, extent, previous occurrences and losses, probability of future occurrences, and impact of climate change)