Profile of the Practice of Epidemiology

1.  Welcome to Session I, Part 2 of the E is for Epi training series from the North Carolina Center for Public Health Preparedness. Welcome to Session I, Part 2 of the E is for Epi training series from the North Carolina Center for Public Health Preparedness.

2. Profile of the Practiceof Epidemiology Now that you have a solid foundation of the Essential Public Health Services and the context that they provide for the practice of Epidemiology, let’s narrow the focus of the discussion to the practice of Epidemiology. Now that you have a solid foundation of the Essential Public Health Services and the context that they provide for the practice of Epidemiology, let’s narrow the focus of the discussion to the practice of Epidemiology.

3. What is Epidemiology? Study of distribution and determinants of states or events in specified populations, and the application of this study to the control of health problems Study risk associated with exposures Identify and control epidemics Monitor population rates of disease and exposure Throughout the centuries, where there have been health problems, there has always been an effort to identify the cause of those health problems. This is really the basis of the public health specialty of epidemiology. Epidemiology is the study of distribution and determinants of states or events in specified populations, and the application of this study to the control of health problems. The purpose of epidemiology is to Study risk associated with exposures Identify and control epidemics, and Monitor population rates of disease and exposure Throughout the centuries, where there have been health problems, there has always been an effort to identify the cause of those health problems. This is really the basis of the public health specialty of epidemiology. Epidemiology is the study of distribution and determinants of states or events in specified populations, and the application of this study to the control of health problems. The purpose of epidemiology is to Study risk associated with exposures Identify and control epidemics, and Monitor population rates of disease and exposure

4. Sub-specialties Infectious diseases Chronic diseases Injury Social Nutritional Occupational Environmental Behavioral Forensic Health care Disaster Public Policy Even though epidemiologists collectively work to study disease determinants and their distribution in the population, there are many sub-specialties that you should know about. As this series progresses, you will have an opportunity to learn about several of these sub-specialties. Let’s just look briefly at these sub-specialties, keeping in mind that there is often overlap between these sub-specialties and epidemiologists will often have more than one area of interest and expertise. You are probably most familiar with the specialty of infectious disease. After all, outbreak investigations are often in the headlines. Infectious diseases are part of the fabric of our existence, and the prevention, identification, and control of these diseases are paramount in the field of epidemiology. But chronic diseases, while perhaps more ‘silent’ killers, are also included in epidemiological work. For example, the Centers for Disease Control and Prevention devotes an entire surveillance survey – the Behavioral Risk Factor Surveillance System (or BRFSS) to monitoring health behaviors such as physical activity, nutrition, smoking and alcohol consumption. All behaviors that directly impact chronic diseases. Cancer and heart disease are also studied via data from population-based screenings. An epidemiologist working in an Injury specialty might study both intentional and unintentional injuries, such as domestic violence or motor vehicle accidents, respectively. Social, Nutritional, and Occupational epidemiologists specialize in the causes of disease. For example, an occupational epidemiologist researches the various health outcomes that may result from exposures in the work environment. Outcomes could include injuries at the worksite, cancers that result from chemical exposures among factory workers, or the impact of high-stress workplaces on risk of heart disease. Environmental epidemiologists work in a variety of settings. They may work on vector control (such as mosquitoes and rodents); they may inspect individual household or municipal water supplies; they may investigate mold and lead exposure in households; they may inspect restaurants to assure compliance with sanitation and food preparation regulations. But all of these activities are more ‘behind the scenes’ – we probably take our environmental epidemiologists for granted! Behavioral specialists study epidemics that originate in behavioral patterns versus via a microorganism or physical agent. For example, cigarette smoking and alcohol abuse fall into the category of epidemics studied by behavioral specialists. Forensic epidemiology is the merging of public health methods in a setting of potential criminal investigation. In the past, epidemiologists might be used to serve as key witnesses – investigative experts, consulting experts, or testimony experts – in the court room to testify about the association between an exposure and illness or death. Two examples of these functions were for silicone breast implants and the medical use of marijuana. More recently, the science of epidemiology has been used in the field in conjunction with law enforcement investigations. One example of this was the October 2001 anthrax attack in Washington, D.C., Florida, and New York City and subsequent white powder incidents. This is more of a trend today: it is becoming more critical for Forensic Epidemiologists to be involved in the investigative stage of cases versus coming in at the testimony stage. The science of epidemiology can even be applied in health care settings. For example, North Carolina has a Hospital-based Public Health Epidemiologists program that places epidemiologists in hospitals to assist with preparedness efforts and serve as liaisons between hospitals and the public sector. Epidemiological surveillance methods are used to monitor trends in the populations served (e.g., demographics); procedures performed; antibiotics used; and types of infections and infection rates. Data resulting from this surveillance are then used in many ways to do things such as assess the efficacy of interventions and subsequently improve practices. A Disaster specialist might work on investigations in the aftermath of natural disasters, such as the December 2004 Tsunami, the frequent hurricanes that battered North Carolina, Virginia, and Florida in 2004, et cetera. OR, there might be environmental disasters due to chemical, radiation, or explosion emergencies. For example, the Three Mile Island nuclear reactor meltdown in 1979 in Middletown, Pennsylvania could have caused a HUGE environmental disaster. Epidemiologists were among the many people and federal agencies conducting extensive radiological investigations. I have saved Public Policy for last, because by now you probably have a sense of the interrelatedness of some of the sub-specialties, and also the powerful political and legal implications for research conducted by epidemiologists. I have already described how epidemiological data can be used in the field or court room in conjunction with criminal investigations, and I described how hospital surveillance data can be used to evaluate programs or treatments in place. There are many more ways in which epidemiological data can be used to influence policy. For example, surveillance of health behavior or health status indicators in the general population generates data that Congressmen and their staffers review when it’s time to allocate the federal budget each year. Even though epidemiologists collectively work to study disease determinants and their distribution in the population, there are many sub-specialties that you should know about. As this series progresses, you will have an opportunity to learn about several of these sub-specialties. Let’s just look briefly at these sub-specialties, keeping in mind that there is often overlap between these sub-specialties and epidemiologists will often have more than one area of interest and expertise. You are probably most familiar with the specialty of infectious disease. After all, outbreak investigations are often in the headlines. Infectious diseases are part of the fabric of our existence, and the prevention, identification, and control of these diseases are paramount in the field of epidemiology. But chronic diseases, while perhaps more ‘silent’ killers, are also included in epidemiological work. For example, the Centers for Disease Control and Prevention devotes an entire surveillance survey – the Behavioral Risk Factor Surveillance System (or BRFSS) to monitoring health behaviors such as physical activity, nutrition, smoking and alcohol consumption. All behaviors that directly impact chronic diseases. Cancer and heart disease are also studied via data from population-based screenings. An epidemiologist working in an Injury specialty might study both intentional and unintentional injuries, such as domestic violence or motor vehicle accidents, respectively. Social, Nutritional, and Occupational epidemiologists specialize in the causes of disease. For example, an occupational epidemiologist researches the various health outcomes that may result from exposures in the work environment. Outcomes could include injuries at the worksite, cancers that result from chemical exposures among factory workers, or the impact of high-stress workplaces on risk of heart disease. Environmental epidemiologists work in a variety of settings. They may work on vector control (such as mosquitoes and rodents); they may inspect individual household or municipal water supplies; they may investigate mold and lead exposure in households; they may inspect restaurants to assure compliance with sanitation and food preparation regulations. But all of these activities are more ‘behind the scenes’ – we probably take our environmental epidemiologists for granted! Behavioral specialists study epidemics that originate in behavioral patterns versus via a microorganism or physical agent. For example, cigarette smoking and alcohol abuse fall into the category of epidemics studied by behavioral specialists. Forensic epidemiology is the merging of public health methods in a setting of potential criminal investigation. In the past, epidemiologists might be used to serve as key witnesses – investigative experts, consulting experts, or testimony experts – in the court room to testify about the association between an exposure and illness or death. Two examples of these functions were for silicone breast implants and the medical use of marijuana. More recently, the science of epidemiology has been used in the field in conjunction with law enforcement investigations. One example of this was the October 2001 anthrax attack in Washington, D.C., Florida, and New York City and subsequent white powder incidents. This is more of a trend today: it is becoming more critical for Forensic Epidemiologists to be involved in the investigative stage of cases versus coming in at the testimony stage. The science of epidemiology can even be applied in health care settings. For example, North Carolina has a Hospital-based Public Health Epidemiologists program that places epidemiologists in hospitals to assist with preparedness efforts and serve as liaisons between hospitals and the public sector. Epidemiological surveillance methods are used to monitor trends in the populations served (e.g., demographics); procedures performed; antibiotics used; and types of infections and infection rates. Data resulting from this surveillance are then used in many ways to do things such as assess the efficacy of interventions and subsequently improve practices. A Disaster specialist might work on investigations in the aftermath of natural disasters, such as the December 2004 Tsunami, the frequent hurricanes that battered North Carolina, Virginia, and Florida in 2004, et cetera. OR, there might be environmental disasters due to chemical, radiation, or explosion emergencies. For example, the Three Mile Island nuclear reactor meltdown in 1979 in Middletown, Pennsylvania could have caused a HUGE environmental disaster. Epidemiologists were among the many people and federal agencies conducting extensive radiological investigations. I have saved Public Policy for last, because by now you probably have a sense of the interrelatedness of some of the sub-specialties, and also the powerful political and legal implications for research conducted by epidemiologists. I have already described how epidemiological data can be used in the field or court room in conjunction with criminal investigations, and I described how hospital surveillance data can be used to evaluate programs or treatments in place. There are many more ways in which epidemiological data can be used to influence policy. For example, surveillance of health behavior or health status indicators in the general population generates data that Congressmen and their staffers review when it’s time to allocate the federal budget each year.

5. Historical Example of Epidemiology in Action John Snow and the Broad Street Pump London, England 1854 Now that you have a sense of the purpose of epidemiology and the diverse range of sub-specialties in the field, let’s back up a bit to look at the history of epidemiology and how it evolved to become the science that contributes to the health of populations in the United States and the world. For thousands of years people have been observing the distribution and determinants of disease. Yet in the 1800s, great advances were made in understanding the cause and prevention of disease. One of the most famous examples of “Epidemiology in Action” that contributed to the control of infectious diseases was the ongoing work of Doctor John Snow, a general physician, surgeon, and anesthesiologist. Dr. Snow is credited with completing one of the first formal outbreak investigations, pioneering methods that are refined yet still used by modern epidemiologists. Now that you have a sense of the purpose of epidemiology and the diverse range of sub-specialties in the field, let’s back up a bit to look at the history of epidemiology and how it evolved to become the science that contributes to the health of populations in the United States and the world. For thousands of years people have been observing the distribution and determinants of disease. Yet in the 1800s, great advances were made in understanding the cause and prevention of disease. One of the most famous examples of “Epidemiology in Action” that contributed to the control of infectious diseases was the ongoing work of Doctor John Snow, a general physician, surgeon, and anesthesiologist. Dr. Snow is credited with completing one of the first formal outbreak investigations, pioneering methods that are refined yet still used by modern epidemiologists.

6. Key Elements in Epidemiology Person Age Sex Race or ethnicity Place Geographic location (epidemic? Pandemic?) Proximity to potential exposure Clustering Time Date / time of exposure or onset of illness Seasonality of infectious diseases Identifying endemic versus epidemic disease rates The three key elements that epidemiologists consider when they enter into an outbreak investigation are: person, place, and time. Person characteristics include Age Sex Race or ethnicity Place can be described by Geographic location (epidemic? Pandemic?) Proximity to potential exposure Clustering The time element can be Date / time of exposure or onset of illness Seasonality of infectious diseases Identifying endemic versus epidemic disease rates I want to walk you through the story of John Snow’s keen investigation of a Cholera epidemic—one of many in that time in history. The epidemic was caused by contaminated water at a particular pump site in London, England in the mid 1800s. You will see how Dr. Snow employed consideration of person, place, and time factors in his effort to pinpoint the source of Cholera infection and implement control measures. The three key elements that epidemiologists consider when they enter into an outbreak investigation are: person, place, and time. Person characteristics include Age Sex Race or ethnicity Place can be described by Geographic location (epidemic? Pandemic?) Proximity to potential exposure Clustering The time element can be Date / time of exposure or onset of illness Seasonality of infectious diseases Identifying endemic versus epidemic disease rates I want to walk you through the story of John Snow’s keen investigation of a Cholera epidemic—one of many in that time in history. The epidemic was caused by contaminated water at a particular pump site in London, England in the mid 1800s. You will see how Dr. Snow employed consideration of person, place, and time factors in his effort to pinpoint the source of Cholera infection and implement control measures.

7. John Snow (1813 – 1858) Even if you have heard people reference this story before, you may not be aware of the fact that Doctor Snow’s work was far from serendipitous, albeit brilliant. He had actually been studying Cholera outbreaks before he tested his theories and methods during this particular outbreak. Dr. Snow published his book, “On the Mode of Communication of Cholera” in 1849, a full five years before the Broad Street Pump epidemic. Dr. Snow then revised his book in 1885 after the Broad Street Pump epidemic. Even if you have heard people reference this story before, you may not be aware of the fact that Doctor Snow’s work was far from serendipitous, albeit brilliant. He had actually been studying Cholera outbreaks before he tested his theories and methods during this particular outbreak. Dr. Snow published his book, “On the Mode of Communication of Cholera” in 1849, a full five years before the Broad Street Pump epidemic. Dr. Snow then revised his book in 1885 after the Broad Street Pump epidemic.

8. Broad St. Pump Cholera Outbreak London, England 1854 Low-level transmission in August Increase of cases August 31 and September 1 79 deaths on Sept. 1 and 2 87% of deaths clustered around Broad St. pump Pump handle removed Sept. 8 Let’s look at a simplified summary of the outbreak investigation events. . . During the month of August, 1854, Dr. Snow noticed low-level transmission of cholera in the Golden Square area. However, during the night of August 31st and throughout the day of September 1st, there was a marked increase in the number of cases and deaths. Dr. Snow approached the General Registrar’s Office and obtained the mortality reports for the week ending September 2nd. From these reports he noted that there were 79 deaths occurring on the 1st or 2nd of September. When mapped, 69 of the 79 persons who died lived closer to the Broad Street pump than to any other public pump. From September 3rd through the 5th, Dr. Snow analyzed the water and found varying amounts of organic matter and on some occasions small, white particles that were visible to the naked eye. This was enough to convince him that the pump was the source of the outbreak. On September 7th he presented his evidence to the board of guardians and, although many did not believe his arguments, the following day the pump handle was removed. Let’s look at a simplified summary of the outbreak investigation events. . . During the month of August, 1854, Dr. Snow noticed low-level transmission of cholera in the Golden Square area. However, during the night of August 31st and throughout the day of September 1st, there was a marked increase in the number of cases and deaths. Dr. Snow approached the General Registrar’s Office and obtained the mortality reports for the week ending September 2nd. From these reports he noted that there were 79 deaths occurring on the 1st or 2nd of September. When mapped, 69 of the 79 persons who died lived closer to the Broad Street pump than to any other public pump. From September 3rd through the 5th, Dr. Snow analyzed the water and found varying amounts of organic matter and on some occasions small, white particles that were visible to the naked eye. This was enough to convince him that the pump was the source of the outbreak. On September 7th he presented his evidence to the board of guardians and, although many did not believe his arguments, the following day the pump handle was removed.

9. Over the weeks that followed, Dr. Snow put together a list of cases with date of onset of illness. The list represented the “Person” and “Time” elements of the “Person, Place, and Time” triad. Here is the beginning of Dr. Snow’s aggregated case list, showing the low-level transmission occurring in August and then the sharp increase in cases beginning in September. From this table, you can see that by the time Snow approached the Board of Guardians on September 7th to remove the pump handle, the epidemic had already peaked and was declining in severity. But often, by the time an outbreak is recognized and basic epidemiological information is collected, an outbreak is beginning to diminish. However, this is often only seen retrospectively, and Dr. Snow acted on the information he had in hopes of preventing further transmission. Over the weeks that followed, Dr. Snow put together a list of cases with date of onset of illness. The list represented the “Person” and “Time” elements of the “Person, Place, and Time” triad. Here is the beginning of Dr. Snow’s aggregated case list, showing the low-level transmission occurring in August and then the sharp increase in cases beginning in September. From this table, you can see that by the time Snow approached the Board of Guardians on September 7th to remove the pump handle, the epidemic had already peaked and was declining in severity. But often, by the time an outbreak is recognized and basic epidemiological information is collected, an outbreak is beginning to diminish. However, this is often only seen retrospectively, and Dr. Snow acted on the information he had in hopes of preventing further transmission.

10. John Snow also generated a map of where the cases resided in order to obtain a more thorough understanding of the outbreak. In this map, the Broad Street pump is located at the tip of the arrow, and the distribution of cases around the pump is shown by the black bars. Each bar indicates a fatal case. In modern Epidemiological practice, this type of case plotting is referred to as a spot map. And in the “Person, Place, and Time” triad, this represents “Place.” In the “Outbreak Investigation Methods” series, you will learn more about listing and plotting Person, Place, and Time data in Epi Info software. In conclusion: 1. Dr. Snow’s investigation and subsequent action demonstrate the basics of public health and epidemiology. Dr. Snow used information about person, place and time to help identify the source of infection so he could take action. He is credited with performing one of the best epidemiological investigations during a time when the science of epidemiology was only beginning to develop. His investigations not only had implications for the science of epidemiology, but also in reshaping the scientific views of what caused disease and how it was spread. John Snow also generated a map of where the cases resided in order to obtain a more thorough understanding of the outbreak. In this map, the Broad Street pump is located at the tip of the arrow, and the distribution of cases around the pump is shown by the black bars. Each bar indicates a fatal case. In modern Epidemiological practice, this type of case plotting is referred to as a spot map. And in the “Person, Place, and Time” triad, this represents “Place.” In the “Outbreak Investigation Methods” series, you will learn more about listing and plotting Person, Place, and Time data in Epi Info software. In conclusion: 1. Dr. Snow’s investigation and subsequent action demonstrate the basics of public health and epidemiology. Dr. Snow used information about person, place and time to help identify the source of infection so he could take action. He is credited with performing one of the best epidemiological investigations during a time when the science of epidemiology was only beginning to develop. His investigations not only had implications for the science of epidemiology, but also in reshaping the scientific views of what caused disease and how it was spread.

11. Another Historical Success Story Smallpox In addition to the story of John Snow’s renowned outbreak investigation, I want to highlight another infectious disease that was successfully tackled over time as the public health infrastructure and the science and practice of epidemiology evolved in the United States in the 20th century: Smallpox. Smallpox is caused by a virus that is transmitted from human to human via air droplets (for example, when you cough or sneeze, you release air droplets). Smallpox spreads most readily during the cool, dry winter months but can be transmitted in any climate and in any part of the world. The only weapons against the disease are vaccination and patient isolation. Vaccination before exposure or within 2 to 3 days after exposure affords almost complete protection against disease. Vaccination as late as 4 to 5 days after exposure may protect against death. In addition to the story of John Snow’s renowned outbreak investigation, I want to highlight another infectious disease that was successfully tackled over time as the public health infrastructure and the science and practice of epidemiology evolved in the United States in the 20th century: Smallpox. Smallpox is caused by a virus that is transmitted from human to human via air droplets (for example, when you cough or sneeze, you release air droplets). Smallpox spreads most readily during the cool, dry winter months but can be transmitted in any climate and in any part of the world. The only weapons against the disease are vaccination and patient isolation. Vaccination before exposure or within 2 to 3 days after exposure affords almost complete protection against disease. Vaccination as late as 4 to 5 days after exposure may protect against death.

12. World Health Organization Formed April 7, 1948 Smallpox eradication Initiated in 1967 Last naturally occurring case in 1977 Declared dead in 1980 The World Health Organization was formed on April 7, 1948 as the United Nation’s agency for health. Its objective was and continues to be the attainment by all peoples of the highest possible level of health. The World Health Organization directed the most impressive public health accomplishment in history – the eradication of smallpox. The eradication campaign was initiated in 1967 and ten years later, in 1977, the last naturally-acquired case occurred in Somalia, and the World Health Organization officially declared the world free of smallpox in 1980. However, samples of the virus were retained at the CDC and Koltsovo, Russia, and smallpox is rated among the most dangerous of all potential biological weapons. Therefore, in the wake of 9/11, the Centers for Disease Control initiated a national campaign in 2003 to vaccinate emergency and medical workers, on a voluntary basis, against smallpox. The U.S. Department of Health and Human Services now requires states to be prepared to immunize their entire population within 10 days. There is supposedly enough smallpox vaccine in the Strategic National Stockpile to immunize approximately 300 million people. The World Health Organization was formed on April 7, 1948 as the United Nation’s agency for health. Its objective was and continues to be the attainment by all peoples of the highest possible level of health. The World Health Organization directed the most impressive public health accomplishment in history – the eradication of smallpox. The eradication campaign was initiated in 1967 and ten years later, in 1977, the last naturally-acquired case occurred in Somalia, and the World Health Organization officially declared the world free of smallpox in 1980. However, samples of the virus were retained at the CDC and Koltsovo, Russia, and smallpox is rated among the most dangerous of all potential biological weapons. Therefore, in the wake of 9/11, the Centers for Disease Control initiated a national campaign in 2003 to vaccinate emergency and medical workers, on a voluntary basis, against smallpox. The U.S. Department of Health and Human Services now requires states to be prepared to immunize their entire population within 10 days. There is supposedly enough smallpox vaccine in the Strategic National Stockpile to immunize approximately 300 million people.

13. Overview Measles Outbreak Methemoglobinemia Outbreak Natural Disaster Now you will be presented with some examples of recent epidemiologic investigations, including an outbreak of measles, a methemoglobinemia outbreak, and mortality related to a hurricane. Now you will be presented with some examples of recent epidemiologic investigations, including an outbreak of measles, a methemoglobinemia outbreak, and mortality related to a hurricane.

14. Measles Outbreak – Iowa 2004 First, we will discuss a measles outbreak that took place in Iowa in 2004. First, we will discuss a measles outbreak that took place in Iowa in 2004.

15. Background on Measles Acute viral illness that can cause severe pneumonia, diarrhea, encephalitis and death Spreads through the air via droplets One of the most highly communicable infectious diseases Not endemic in the US due to high vaccination rates Iowa had not seen a case since 1996 Measles is an acute viral illness that can cause severe pneumonia, diarrhea, encephalitis and death. It is spread through the air via droplets, much like the common cold or influenza and is one of the most highly communicable infectious diseases. Fortunately due to high vaccination rates in the US, measles is not endemic. Typically there are fewer than <100 cases in the US per year. Iowa had not seen a case since 1996.Measles is an acute viral illness that can cause severe pneumonia, diarrhea, encephalitis and death. It is spread through the air via droplets, much like the common cold or influenza and is one of the most highly communicable infectious diseases. Fortunately due to high vaccination rates in the US, measles is not endemic. Typically there are fewer than <100 cases in the US per year. Iowa had not seen a case since 1996.

16. March 2004 – The Beginning Group of 30 from Iowa college traveled to India India had 52,000 cases of measles in 2002 Majority of group not vaccinated because of religious reasons Six members of group got measles while in India In March of 2004, a group of 30 people from an Iowa college traveled to India, where measles is prevalent, with 52,000 cases occurring in 2002. The college was part of an insular Iowa community with very low vaccination rates. In fact, the community’s K-12 school had a vaccination rate of 59% for vaccines required for school entry, compared to a rate of >90% by age 3 years for the US as a whole. The Majority of the group was not vaccinated due to non-medical exemptions. In Iowa, an individual can avoid vaccination if an affidavit is submitted stating that the immunization conflicts with the tenets and practices of a recognized religious denomination of which the applicant is a member. Six members of this group contracted measles while in India. In March of 2004, a group of 30 people from an Iowa college traveled to India, where measles is prevalent, with 52,000 cases occurring in 2002. The college was part of an insular Iowa community with very low vaccination rates. In fact, the community’s K-12 school had a vaccination rate of 59% for vaccines required for school entry, compared to a rate of >90% by age 3 years for the US as a whole. The Majority of the group was not vaccinated due to non-medical exemptions. In Iowa, an individual can avoid vaccination if an affidavit is submitted stating that the immunization conflicts with the tenets and practices of a recognized religious denomination of which the applicant is a member. Six members of this group contracted measles while in India.

17. Public Health Recommendations Six persons with measles asked not to return to US for at least 4 days after rash onset Contacts of case-patients who were not immune to measles asked to stay in India for 18 days after the last possible exposure At the Iowa State Health Department , epidemiologists recommended that the six persons with measles not return to US for at least 4 days after rash onset. They also recommended that the contacts of case-patients who were not immune to measles stay in India for 18 days after the last possible exposure. At the Iowa State Health Department , epidemiologists recommended that the six persons with measles not return to US for at least 4 days after rash onset. They also recommended that the contacts of case-patients who were not immune to measles stay in India for 18 days after the last possible exposure.

18. Here Comes Trouble One of the unvaccinated students returned to the US early, arriving in Iowa on March 13 During travel, student had a cough and conjunctivitis and within 24 hours of arrival had a rash; subsequently confirmed to have measles Case-patient spread measles to 2 additional persons However, one of the unvaccinated contacts returned to the US early, arriving in Iowa on March 13. This student traveled on 3 flights through 4 airports to get home. During travel, the contact had a cough and conjunctivitis, and within 24 hours of arrival in the US had a rash. This person was subsequently confirmed to have measles. In the end, the case-patient spread measles to 2 additional persons - 1 was seated next to the initial case on the plane and had been previously vaccinated; the other was a family member of the case-patient who had no history of vaccination.However, one of the unvaccinated contacts returned to the US early, arriving in Iowa on March 13. This student traveled on 3 flights through 4 airports to get home. During travel, the contact had a cough and conjunctivitis, and within 24 hours of arrival in the US had a rash. This person was subsequently confirmed to have measles. In the end, the case-patient spread measles to 2 additional persons - 1 was seated next to the initial case on the plane and had been previously vaccinated; the other was a family member of the case-patient who had no history of vaccination.

19. Public Health Response Worked with airline, media, and case-patients to identify persons potentially exposed to case-patients Conducted vaccination clinics for exposed persons Enforced voluntary and involuntary isolation and quarantine The public health response to this incident required working with the airline, the media, and case-patients to identify persons potentially exposed to measles. Vaccination clinics were held for exposed persons – approximately 200 persons given either vaccine or immune-globulin. Note that this activity supports Essential Service #5 “Develop policies and plans that support individual and community health efforts” The public health response also required enforcing voluntary and involuntary isolation and quarantine. 3 cases were placed in voluntary isolation, and were monitored by home visits and calls from the local public health agency Two exposed healthcare workers placed under voluntary quarantine for two weeks, and Seven exposed community members placed under involuntary quarantine served by the local public health agency and local law enforcement. Note that this supports Essential Service #6 “Enforce laws and regulations that protect health and ensure safety”The public health response to this incident required working with the airline, the media, and case-patients to identify persons potentially exposed to measles. Vaccination clinics were held for exposed persons – approximately 200 persons given either vaccine or immune-globulin. Note that this activity supports Essential Service #5 “Develop policies and plans that support individual and community health efforts” The public health response also required enforcing voluntary and involuntary isolation and quarantine. 3 cases were placed in voluntary isolation, and were monitored by home visits and calls from the local public health agency Two exposed healthcare workers placed under voluntary quarantine for two weeks, and Seven exposed community members placed under involuntary quarantine served by the local public health agency and local law enforcement. Note that this supports Essential Service #6 “Enforce laws and regulations that protect health and ensure safety”

20. Methemoglobinemia Outbreak – 2003 The next situation I will discuss with you is an outbreak of methemoglobinemia that occurred in 2003. The next situation I will discuss with you is an outbreak of methemoglobinemia that occurred in 2003.

21. What is Methemoglobinemia? Change in the hemoglobin molecule of red blood cells that impairs the ability to carry oxygen Can result in headaches, shortness of breath, nausea, increased heart rate, weakness, fatigue, and a bluish discoloration of the skin Caused by ingestion or inhalation of oxidizing agents Methemoglobinemia is a change in the hemoglobin molecule of red blood cells that impairs the ability of the red blood cell to carry oxygen. The illness can result in headaches, shortness of breath, nausea, increased heart rate, weakness, fatigue, and cyanosis (which is bluish discoloration of the skin). Methemoglobinemia is most commonly caused by ingestion or inhalation of oxidizing agents such as nitrates or nitrites Methemoglobinemia is a change in the hemoglobin molecule of red blood cells that impairs the ability of the red blood cell to carry oxygen. The illness can result in headaches, shortness of breath, nausea, increased heart rate, weakness, fatigue, and cyanosis (which is bluish discoloration of the skin). Methemoglobinemia is most commonly caused by ingestion or inhalation of oxidizing agents such as nitrates or nitrites

22. Wedding Reception Approximately 500 persons in attendance Attendees began to feel ill after arriving at the reception Several attendees were transported by ambulance to local emergency rooms A total of 83 attendees sought emergency medical care, with 20 being hospitalized Diagnosis of methemoglobinemia was made This outbreak illustrates Essential Service #2 “Diagnose and investigate health problems and health hazards in the community” The public health department was tipped off about the outbreak by the media who were calling to find out what was going on at a wedding reception. There were approximately 500 persons in attendance at the wedding reception, and the attendees began to feel ill shortly after arriving there. This is an unusual outbreak. In a typical foodborne outbreak many hours or days will go by before people start to become ill, but in this case, people were passing out before all the guests even arrived at the reception Several attendees were transported by ambulance to local emergency rooms In all, a total of 83 attendees sought emergency medical care, with 20 being hospitalized The wedding was on a Saturday afternoon – by that evening public health staff were present at the reception site and at local emergency rooms to investigate. A diagnosis of methemoglobinemia was made. This outbreak illustrates Essential Service #2 “Diagnose and investigate health problems and health hazards in the community” The public health department was tipped off about the outbreak by the media who were calling to find out what was going on at a wedding reception. There were approximately 500 persons in attendance at the wedding reception, and the attendees began to feel ill shortly after arriving there. This is an unusual outbreak. In a typical foodborne outbreak many hours or days will go by before people start to become ill, but in this case, people were passing out before all the guests even arrived at the reception Several attendees were transported by ambulance to local emergency rooms In all, a total of 83 attendees sought emergency medical care, with 20 being hospitalized The wedding was on a Saturday afternoon – by that evening public health staff were present at the reception site and at local emergency rooms to investigate. A diagnosis of methemoglobinemia was made.

23. Further Investigation After interviewing several attendees, a punch served at the reception was identified as a potential source of the outbreak After interviewing several attendees, a punch served at the reception was identified as a potential source of the outbreak. Several reception attendees reported that the punch didn’t taste very good or didn’t taste right.After interviewing several attendees, a punch served at the reception was identified as a potential source of the outbreak. Several reception attendees reported that the punch didn’t taste very good or didn’t taste right.

24. The Punch Obtained frozen through a local caterer Caterer obtained a flavor mix from an out-of-state company Flavor mix provided to a local food processing company where sugar and citric acid are added Caterer added water and froze punch for sale Same lot of punch served at wedding reception was served at a baby shower The punch at the reception was obtained frozen through a local caterer. The caterer obtained a flavor mix from an out-of-state company to make the punch, the flavor mix was then provided to a local food processing company where sugar and citric acid were added. Then the caterer added water and froze the punch for sale. It turned out that the same lot of punch served at the wedding reception had been served at a baby shower. Upon investigation, baby shower attendees said the punch didn’t taste good; 8 of 13 attendees developed symptoms but none required emergency care.The punch at the reception was obtained frozen through a local caterer. The caterer obtained a flavor mix from an out-of-state company to make the punch, the flavor mix was then provided to a local food processing company where sugar and citric acid were added. Then the caterer added water and froze the punch for sale. It turned out that the same lot of punch served at the wedding reception had been served at a baby shower. Upon investigation, baby shower attendees said the punch didn’t taste good; 8 of 13 attendees developed symptoms but none required emergency care.

25. What Happened? Samples from the punch and from the dry mix indicated sodium nitrite contamination The amount of sodium nitrite in the mix and the lack of citric acid in the mix suggested that sodium nitrite was added instead of citric acid Both sodium nitrite and citric acid are white powders and both were used at the food processing plant Samples from the punch that was served and from the dry mix indicated the presence of sodium nitrite contamination The amount of sodium nitrite in the mix, and the lack of citric acid in the mix, suggested that sodium nitrite was accidentally added instead of citric acid Both sodium nitrite and citric acid are white powders and both were used at the food processing plant. This mix up explained the outbreak. Samples from the punch that was served and from the dry mix indicated the presence of sodium nitrite contamination The amount of sodium nitrite in the mix, and the lack of citric acid in the mix, suggested that sodium nitrite was accidentally added instead of citric acid Both sodium nitrite and citric acid are white powders and both were used at the food processing plant. This mix up explained the outbreak.

26. Hurricane Isabel Related Mortality – Virginia, 2003 The last case study that I want to discuss is based on a natural disaster. In late September 2003, Hurricane Isabel made landfall on the mid Atlantic coast of the United States. In the state of Virginia, 32 deaths were associated with the hurricane. Epidemiologists reviewed data from the state Office of Vital Records/ Health Statistics, and storm assessment and emergency response reports from the Governor’s Office. The last case study that I want to discuss is based on a natural disaster. In late September 2003, Hurricane Isabel made landfall on the mid Atlantic coast of the United States. In the state of Virginia, 32 deaths were associated with the hurricane. Epidemiologists reviewed data from the state Office of Vital Records/ Health Statistics, and storm assessment and emergency response reports from the Governor’s Office.

27. Hurricane Isabel Related Mortality – Virginia, 2003 Profile of Deaths Age range 7 – 85; 66% over age 45 Most deaths due to drowning, fallen trees, power outages 34% due to traumatic head injuries 28% with confirmed presence of alcohol or drugs 12 deaths “direct”; 20 deaths “indirect” Among the deaths, the ages ranged from 7 to 85 years old; 66% were over age 45. Most deaths were due to drowning, fallen trees, and power outages, while about a third were due to traumatic head injuries and in 28% of the deaths alcohol or drugs were present. 12 deaths were a “direct” result of the hurricane; and 20 deaths were “indirect” Epidemiologists used criteria set forth by the National Hurricane Center (NHC) of the National Oceanic and Atmospheric Administration (NOAA) to classify deaths as direct or indirect. For example, a death due to intoxication (someone under the influence of alcohol who fell into water and drowned immediately after the hurricane) would be classified as indirect. Whereas a death due to high winds knocking over a tree and killing someone during the storm would be classified as direct. This case study is an example of a project for BOTH epidemiologists specializing in disasters and intentional and unintentional injuries. In terms of preventing injuries, general education about safety during and after a hurricane (such as avoiding standing water and fallen power lines) is one example of how public health professionals would work with the media to get specialized information to the public before a hurricane made landfall. Additional epidemiology specialists might be involved in researching other aspects of the post-hurricane situation. For example, just as we have seen in the news with the aftermath of the Tsunami in the Indian Ocean, if people are left without basic shelter and sanitary conditions, including safe drinking water, then infectious disease and environmental epidemiologists also need to become part of the problem solving equation. So in conclusion, I hope that these three, non-bioterrorism case studies give you a glimpse of the diverse, day-to-day situations that arise and the application of the many epidemiology specialties. Among the deaths, the ages ranged from 7 to 85 years old; 66% were over age 45. Most deaths were due to drowning, fallen trees, and power outages, while about a third were due to traumatic head injuries and in 28% of the deaths alcohol or drugs were present. 12 deaths were a “direct” result of the hurricane; and 20 deaths were “indirect” Epidemiologists used criteria set forth by the National Hurricane Center (NHC) of the National Oceanic and Atmospheric Administration (NOAA) to classify deaths as direct or indirect. For example, a death due to intoxication (someone under the influence of alcohol who fell into water and drowned immediately after the hurricane) would be classified as indirect. Whereas a death due to high winds knocking over a tree and killing someone during the storm would be classified as direct. This case study is an example of a project for BOTH epidemiologists specializing in disasters and intentional and unintentional injuries. In terms of preventing injuries, general education about safety during and after a hurricane (such as avoiding standing water and fallen power lines) is one example of how public health professionals would work with the media to get specialized information to the public before a hurricane made landfall. Additional epidemiology specialists might be involved in researching other aspects of the post-hurricane situation. For example, just as we have seen in the news with the aftermath of the Tsunami in the Indian Ocean, if people are left without basic shelter and sanitary conditions, including safe drinking water, then infectious disease and environmental epidemiologists also need to become part of the problem solving equation. So in conclusion, I hope that these three, non-bioterrorism case studies give you a glimpse of the diverse, day-to-day situations that arise and the application of the many epidemiology specialties.

28. Wide range of activities conducted by epidemiologists Opportunity to work with numerous partners from a variety of fields Closing Thoughts In closing, there are a wide range of activities conducted by epidemiologists. Being an epidemiologist provides the opportunity to work with numerous partners from a variety of fields.In closing, there are a wide range of activities conducted by epidemiologists. Being an epidemiologist provides the opportunity to work with numerous partners from a variety of fields.

29. Session Summary The Ten Essential Services of public health create a “common ground” and a comprehensive infrastructure that provides a supportive context for any public health priority in a community. Epidemiology is the study of distribution and determinants of states or events in specified populations, and the application of this study to the control of health problems. In summary of session 1: The Ten Essential Services of public health create a “common ground” and a comprehensive infrastructure that provides a supportive context for any public health priority in a community. Epidemiology is the study of distribution and determinants of states of health or events in specified populations, and the application of this study to the control of health problems. [cont. next slide]In summary of session 1: The Ten Essential Services of public health create a “common ground” and a comprehensive infrastructure that provides a supportive context for any public health priority in a community. Epidemiology is the study of distribution and determinants of states of health or events in specified populations, and the application of this study to the control of health problems. [cont. next slide]

30. Session Summary There are many sub-specialties in Epidemiology that often complement each other in outbreak investigations and other public health research settings. John Snow’s investigation using information about person, place and time to help identify the source of a Cholera outbreak in 19th century England was one of the best epidemiological investigations of his time, with implications for the science of epidemiology, and views of what caused disease and how it was spread. There are many sub-specialties in epidemiology that often complement each other in outbreak investigations and other public health research settings. John Snow’s investigation using information about person, place and time to help identify the source of a Cholera outbreak in 19th century England was one of the best epidemiological investigations of his time. His investigations had implications for the science of epidemiology, and reshaped the scientific views of what caused disease and how it was spread. There are many sub-specialties in epidemiology that often complement each other in outbreak investigations and other public health research settings. John Snow’s investigation using information about person, place and time to help identify the source of a Cholera outbreak in 19th century England was one of the best epidemiological investigations of his time. His investigations had implications for the science of epidemiology, and reshaped the scientific views of what caused disease and how it was spread.

31. References and Resources Gordis, L. ( 2000). Epidemiology: 2nd Edition. W. B. Saunders Company: Philadelphia. Hearne, S. et al (2004). Ready or Not? Protecting the Public’s Health in The Age of Bioterrorism. Trust for America’s Health Report. http://healthyamericans.org/reports/bioterror04/BioTerror04Report.pdf Henderson DA. Bioterrorism as a public health threat. Emerg Infect Dis 1998;4:488-92. Kipp, A. (2004). “Overview of Epidemiology in Public Health.” North Carolina Center for Public Health Preparedness, UNC Chapel Hill School of Public Health. http://www.sph.unc.edu/nccphp/training/all_trainings/at_epidmeth.htm

32. References and Resources Last, J.M. (1988). A Dictionary of Epidemiology. Oxford University Press: New York. MacDonald, P. and Mountcastle, S. (2004). Forensic Epidemiology Part I. North Carolina Center for Public Health Preparedness, UNC Chapel Hill School of Public Health. http://www.sph.unc.edu/nccphp/training/all_trainings/at_forensic.htm Measles Outbreak Information (Iowa specific) http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5311a6.htm http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5341a3.htm Methemoglobinemia Outbreak Information (Iowa specific) http://www.idph.state.ia.us/common/press_releases/2003/Wedding_investigate.asp

33. References and Resources   North Carolina Center for Public Health Preparedness (2003). Virginia Public Health Workforce Training Needs Assessment: Final Report. UNC Chapel Hill, North Carolina. Northwest Center for Public Health Practice, University of Washington School of Public Health and Community Medicine (September 2004). Competency-based Training for Public Health Epidemiology. http://www.nwcphp.org/epi/comps Pfau, S. (2004). Ten Essential Public Health Services. Kansas University Workgroup on Health Promotion and Community Development. Online Community Tool Box: http://ctb.ku.edu/ St. George, D.M.M. (2004). First Responder Epidemiology Training Course. North Carolina Center for Public Health Preparedness.

34. References and Resources Trust for America’s Health (December 2004). Ready or Not? Protecting The Public’s Health in the Age of Bioterrorism: 2004 http://www.healthyamericans.org UNC Chapel Hill School of Public Health (2004). John Snow – Broad Street Pump Outbreak Case Study http://www.sph.unc.edu/courses/john_snow U.S. Nuclear Regulatory Commission. Fact Sheet on the Incident at Three Mile Island. U.S. Nuclear Regulatory Commission, Washington, D.C. http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/3mile-isle.html