Influenza: Public Health Perspective 2003

1. Influenza: Public Health Perspective 2003 Joann Schulte, DO, MPH Angela Fix, MPH Bureau of Epidemiology Florida Department of Health This presentation is designed to help you understand more about influenza and what is going on during the winter of 2003-2004.This presentation is designed to help you understand more about influenza and what is going on during the winter of 2003-2004.

2. Why Worry About Flu? > 6000 hospitalizations in Florida each year > 3000 pneumonia/ flu deaths in Florida each year nosocomial/ community outbreaks it�s preventable it�s unpredictable (epidemics/ pandemics) 2003: new strain of Influenza A has led to increased demand for vaccine We worry about the flu in Florida because it causes more than 6000 hospitalizations annually and there are an estimated 3000 deaths from flu and pneumonia each year. In addition, there are nosocomial and community outbreaks. The disease is preventable, but it�s unpredictable as well. 2003 is a perfect example of that. There�s a slight variation in the influenza a virus this year and that has led to an overwhelming demand for vaccine. We worry about the flu in Florida because it causes more than 6000 hospitalizations annually and there are an estimated 3000 deaths from flu and pneumonia each year. In addition, there are nosocomial and community outbreaks. The disease is preventable, but it�s unpredictable as well. 2003 is a perfect example of that. There�s a slight variation in the influenza a virus this year and that has led to an overwhelming demand for vaccine.

3. Influenza virus This slide is meant to explain the flu virus and how it mutates and what that means for numbers of flu cases from year to year. This is a slide of a electron microscope view of the influenza virus. Those knobby things sticking out are two antigens called hemagglutinin and neuraminidase. When you hear scientists talk about the new strains of the flu vaccine you will often hear them talk about H and N. The H. stands for hemagglutinin which are shown in yellow in the upper right hand part of the slide. The N showing in blue on the slide stands for neuraminidase. It is the changes in the H and N that produces changes in the flu virus every year.This slide is meant to explain the flu virus and how it mutates and what that means for numbers of flu cases from year to year. This is a slide of a electron microscope view of the influenza virus. Those knobby things sticking out are two antigens called hemagglutinin and neuraminidase. When you hear scientists talk about the new strains of the flu vaccine you will often hear them talk about H and N. The H. stands for hemagglutinin which are shown in yellow in the upper right hand part of the slide. The N showing in blue on the slide stands for neuraminidase. It is the changes in the H and N that produces changes in the flu virus every year.

4. Influenza A (HxNy) Hemagglutinin & Neuraminidase Subtypes This slide shows the different varieties of H. and N that exist in nature. They combine in different forms on the surface of the flu virus to produce new strains every year. As you can see they can combine in many ways. To make things more complicated, the flu virus strains can exist in different animals. The virus strains mutate and combine in different ways and that keeps researchers, lab experts and vaccine manufacturers scrambling each year. This year�s flu is rarely the same as last year�s flu. Another important point here is that you may see references to different strains of the flu virus such as H3N2. That tells you how the current strain of has combined.This slide shows the different varieties of H. and N that exist in nature. They combine in different forms on the surface of the flu virus to produce new strains every year. As you can see they can combine in many ways. To make things more complicated, the flu virus strains can exist in different animals. The virus strains mutate and combine in different ways and that keeps researchers, lab experts and vaccine manufacturers scrambling each year. This year�s flu is rarely the same as last year�s flu. Another important point here is that you may see references to different strains of the flu virus such as H3N2. That tells you how the current strain of has combined.

5. This slide is important because it shows how the different animals and man give the flu virus an opportunity to recombining mutate.This slide is important because it shows how the different animals and man give the flu virus an opportunity to recombining mutate.

6. Influenza virus-antigenic changes Drift Minor Change, Same Subtype Associated with Epidemics This is happening in the 2003-2004 season Shift Major Change, New Subtype H1N1 H2N1 Associated with pandemic This is what happened in 1918 pandemic The flu virus can mutate or change its genes. If this happens gradually it is called antigenic drift. That is what has gone on this year in 2003. If there is a major sudden shift in the genes, then it is called antigenic shift. Those shifts are associated with pandemics like the 1918 influenza pandemic. The flu virus can mutate or change its genes. If this happens gradually it is called antigenic drift. That is what has gone on this year in 2003. If there is a major sudden shift in the genes, then it is called antigenic shift. Those shifts are associated with pandemics like the 1918 influenza pandemic.

7. This slide is intended to illustrate why the flu vaccine that is available for a given year may not match the strain that actually circulates that same year. In the early spring of each year, a committee of experts recommends what strain should be in the vaccine. Vaccine production takes months before any supplies are available in the fall months of the year. So the formulation of the flu vaccine we are using now was decided on last spring. But the flu virus strain circulating now is somewhat different. This slide is intended to illustrate why the flu vaccine that is available for a given year may not match the strain that actually circulates that same year. In the early spring of each year, a committee of experts recommends what strain should be in the vaccine. Vaccine production takes months before any supplies are available in the fall months of the year. So the formulation of the flu vaccine we are using now was decided on last spring. But the flu virus strain circulating now is somewhat different.

8. So what can we do about the flu? Vaccinate to prevent it Employ good hygiene to prevent it Avoid crowded places & stay home if ill Do laboratory testing to diagnose strains circulating Use drugs for prophylaxis or for treatment So what can we do about the flu? Early on, we can vaccinate to prevent it. We can always use good hygiene to prevent it. You can avoid crowded places and stay home if you are sick. Physicians and public health departments can do laboratory testing to diagnosis trains are circulating. That is important because that information is important in preparing next year�s vaccine. You can also use drugs for prophylaxis or treatment. We�ll talk about more these topics on the next several slides.So what can we do about the flu? Early on, we can vaccinate to prevent it. We can always use good hygiene to prevent it. You can avoid crowded places and stay home if you are sick. Physicians and public health departments can do laboratory testing to diagnosis trains are circulating. That is important because that information is important in preparing next year�s vaccine. You can also use drugs for prophylaxis or treatment. We�ll talk about more these topics on the next several slides.

9. Flu vaccine in 2003-4 3 vaccines: 2 inactivated injection & 1 live, attenuated nasal mist Increased demand has led to short supplies Most vulnerable population (elderly, children, chronically ill) get priority Others should get nasal flu vaccine Prevention is very important In 2003-2004, three vaccines are available. Two are inactivated vaccines that are given as a shot. The newest vaccine is a lot attenuated strain of the virus is given nasally. Because influenza has hit early, more people want to be vaccinated and the demand exceeds supply. As a result the most honorable populations get priority for vaccination for the vaccines given as shots. These are the elderly > 65 years, children aged 6-23 months and persons who are chronically ill. Examples of these illnesses include people with heart disease, lung disease and immunocompromised conditions. The new nasal flu vaccine is recommended for people aged 5-49 years. Other kinds of prevention are also very important.In 2003-2004, three vaccines are available. Two are inactivated vaccines that are given as a shot. The newest vaccine is a lot attenuated strain of the virus is given nasally. Because influenza has hit early, more people want to be vaccinated and the demand exceeds supply. As a result the most honorable populations get priority for vaccination for the vaccines given as shots. These are the elderly > 65 years, children aged 6-23 months and persons who are chronically ill. Examples of these illnesses include people with heart disease, lung disease and immunocompromised conditions. The new nasal flu vaccine is recommended for people aged 5-49 years. Other kinds of prevention are also very important.

10. Testing for influenza Culture 1-5 days; �Gold standard� Direct Specimen Immunofluorescence Limited number of labs Molecular Not yet widely available/used Serology Retrospective (after the fact) Rapid EIA and �EIA-Like� Tests Results in 24 hours Note: The nasal mist vaccine may replicate in cell cultures and produce a positive result in rapid tests up to 3 weeks post-immunization This slide shows the kind of testing is available. There are three points that matter here. One is the culture is required to determine what strain of flotation has and that kind of testing is usually done at the state laboratories. The rapid tests are available in physicians offices and are most commonly used if you see your private physician. It is also important to note that a person who has had the nasal flu vaccine is new may have a positive test results for up to three weeks after immunization.This slide shows the kind of testing is available. There are three points that matter here. One is the culture is required to determine what strain of flotation has and that kind of testing is usually done at the state laboratories. The rapid tests are available in physicians offices and are most commonly used if you see your private physician. It is also important to note that a person who has had the nasal flu vaccine is new may have a positive test results for up to three weeks after immunization.

11. Drugs to prevent & treat influenza 4 antiviral drugs are licensed to treat flu by decreasing severity of symptoms 3 drugs of the 4 can be used for prophylaxis All drugs are require a prescription Patients should see a physician Health department does not provide drugs There are drugs available to prevent and treat influenza. There are 4 drugs that can be used to decreases severity of flu symptoms if given during the first several days of illness. Three of the four drugs can also be used for prophylaxis. All the drugs require prescription and patients must see a physician to get them. Neither the Florida Department of Health nor local health departments provide these drugs for patients.There are drugs available to prevent and treat influenza. There are 4 drugs that can be used to decreases severity of flu symptoms if given during the first several days of illness. Three of the four drugs can also be used for prophylaxis. All the drugs require prescription and patients must see a physician to get them. Neither the Florida Department of Health nor local health departments provide these drugs for patients.

12. What are other prevention measures? Avoid close contact with sick people Stay home if you are sick Cover your mouth & nose with a tissue if you cough or sneeze Wash your hands often with soap and water or alcohol-based cleanser Avoid touching your ears, nose or mouth So what else can you do? There are some common sense measures. Avoid close contact with sick people. Stay home if you�re sick & keep your children if they are sick. Cover your mouth and nose with a tissue if you cough or sneeze. Wash your hands often with soap and warm water or on alcohol-based cleanser. Avoid touching your ears, nose or mouth.So what else can you do? There are some common sense measures. Avoid close contact with sick people. Stay home if you�re sick & keep your children if they are sick. Cover your mouth and nose with a tissue if you cough or sneeze. Wash your hands often with soap and warm water or on alcohol-based cleanser. Avoid touching your ears, nose or mouth.

13. Influenza: Clinical Syndrome Incubation period 1 to 3 days Abrupt onset of high fever and chills Associated symptoms headache, malaise, myalgia, cough, sore throat, nasal congestion Duration of intense symptoms 3 to 5 days Prolonged recovery Note: CDC definition of influenza-like illness Temp > 100�F orally and either cough or sore throat This slide talks about the clinical syndrome of influenza. The incubation period is one to three days. There�s a sudden onset of high fever & chills. Very often people also have headaches, malaise, muscle aches, cough, sore throat and nasal congestion. They feel really bad for three to five days and make a prolonged recovery. To monitor influential like illness, the CDC also has a definition for influenza like illness.This slide talks about the clinical syndrome of influenza. The incubation period is one to three days. There�s a sudden onset of high fever & chills. Very often people also have headaches, malaise, muscle aches, cough, sore throat and nasal congestion. They feel really bad for three to five days and make a prolonged recovery. To monitor influential like illness, the CDC also has a definition for influenza like illness.

14. What is flu and what is ILI? Flu: clinical symptoms & laboratory confirmation ILI (influenza like illness): clinical symptoms and no laboratory testing For public health purposes, a person has to have clinical symptoms and laboratory confirmation to be considered a confirmed influenza case. influenza like illness is clinical illness with no confirmed laboratory testing, and it is important determining how many people may be ill. More about that in the next several slides.For public health purposes, a person has to have clinical symptoms and laboratory confirmation to be considered a confirmed influenza case. influenza like illness is clinical illness with no confirmed laboratory testing, and it is important determining how many people may be ill. More about that in the next several slides.

15. Why is every case of flu not reportable in Florida? Sporadic cases-No Massive undertaking Diagnostics Outbreaks-Yes Mortality-Yes (vital statistics) There are very specific reasons that each individual case of influenza is not reportable in the state. Sporadic cases are not reported because the work requires massive and the diagnostic testing required could overwhelm the state laboratories. However a sentinel surveillance system is in place to detect outbreaks of influenza, the strains of influenza circulating and how mortality (vital statistics) is impacted by outbreaks. The reality is if we counted every flu case we would not be doing anything else but counting flu cases.There are very specific reasons that each individual case of influenza is not reportable in the state. Sporadic cases are not reported because the work requires massive and the diagnostic testing required could overwhelm the state laboratories. However a sentinel surveillance system is in place to detect outbreaks of influenza, the strains of influenza circulating and how mortality (vital statistics) is impacted by outbreaks. The reality is if we counted every flu case we would not be doing anything else but counting flu cases.

16. Flu surveillance in Florida and US Determine when viruses are circulating Identify strains and detect changes in strains Monitor influenza-related illness Measure impact of influenza on deaths The goals of flu surveillance in Florida and the U.S. are four fold. We want to determine when viruses are circulating, what those strains are, how those strains have changed. We also want to monitor influenza like illness and determine how influenza is impacting the mortality or number of deaths.The goals of flu surveillance in Florida and the U.S. are four fold. We want to determine when viruses are circulating, what those strains are, how those strains have changed. We also want to monitor influenza like illness and determine how influenza is impacting the mortality or number of deaths.

17. National surveillance Influenza Like Illness (ILI): Virus strains: Outbreaks: Mortality: Sentinel Physicians ILI Surveillance Network 70 Laboratories State Health Dept. Epidemiologists 121 Cities Flu and Pneumonia Mortality System National surveillance consists of four elements. Influenza like illness is reported as number of patients seen. Virus strain information is collected through 70 laboratories, and this information is important in detecting what influenza strains are circulating. This information is later used in determining what strain of the flu virus will be contained in the next season�s flu vaccine. State health department epidemiologists monitor flu outbreaks and mortality from both flu and ammonia is reported by 121cities. It�s important to note that the influenza surveillance system differs from that for many other diseases where every case is supposed to be reported in detail and counted.National surveillance consists of four elements. Influenza like illness is reported as number of patients seen. Virus strain information is collected through 70 laboratories, and this information is important in detecting what influenza strains are circulating. This information is later used in determining what strain of the flu virus will be contained in the next season�s flu vaccine. State health department epidemiologists monitor flu outbreaks and mortality from both flu and ammonia is reported by 121cities. It�s important to note that the influenza surveillance system differs from that for many other diseases where every case is supposed to be reported in detail and counted.

18. Florida surveillance in Florida 92 sentinel physicians in 2002-2003 2 WHO labs: DOH Jacksonville+Tampa Flu test data also from hospitals, private influenza surveillance network 4 cities reporting mortality (Jacksonville, Miami, St. Petersburg, and Tampa) Influenza outbreaks reportable to DOH Flu surveillance in Florida is meant to detect the presence of specific strains of the virus and outbreaks of influenza. It is not meant to provide detailed information on every influenza case. 92 Sentinel physicians report either influenza like illness or submit clinical specimens for testing or both. 2 state labs in Jacksonville and Tampa can do confirmatory work to type influenza including culture. DOH also monitors for test data from hospitals and reference labs. Four Florida cities also submit data on mortality which is used in calculating or tally rates. Influenza outbreaks are reportable to the Department of Health.Flu surveillance in Florida is meant to detect the presence of specific strains of the virus and outbreaks of influenza. It is not meant to provide detailed information on every influenza case. 92 Sentinel physicians report either influenza like illness or submit clinical specimens for testing or both. 2 state labs in Jacksonville and Tampa can do confirmatory work to type influenza including culture. DOH also monitors for test data from hospitals and reference labs. Four Florida cities also submit data on mortality which is used in calculating or tally rates. Influenza outbreaks are reportable to the Department of Health.

19. This map with the blue marks shows where the sentinel physicians are located within 2003-2004 season.This map with the blue marks shows where the sentinel physicians are located within 2003-2004 season.

20. The burden of flu illness highest in kids We�ve talked about what flu is, how to prevent & treat it. Now we want to talk about who has the most impact on. Children most often are sick. This slide shows influenza like illness and influenza by age group. The pink line is influenza like illness and you can see that it decreases with age. The green line is its influence isolates confirmed by the laboratory testing and you can see this also declines with age.We�ve talked about what flu is, how to prevent & treat it. Now we want to talk about who has the most impact on. Children most often are sick. This slide shows influenza like illness and influenza by age group. The pink line is influenza like illness and you can see that it decreases with age. The green line is its influence isolates confirmed by the laboratory testing and you can see this also declines with age.

21. This slide shows influenza mortality during certain years of epidemics. The Y. access shows the deaths per 100,000 population. The x-axis shows age. The important thing to understand here is that the elderly are more likely to die. The different colored lines show different epidemic years and you can see mortality increases with age.This slide shows influenza mortality during certain years of epidemics. The Y. access shows the deaths per 100,000 population. The x-axis shows age. The important thing to understand here is that the elderly are more likely to die. The different colored lines show different epidemic years and you can see mortality increases with age.

22. Any questions? Try http://www.cdc.gov/flu If you need additional information, please look at the CDC web site.If you need additional information, please look at the CDC web site.