Presentation on theme: "1 Seasonal Influenza versus Avian Flu and Public Healths Role : Content adapted for BugLine from presentation by : Cassandra D. Youmans, MD, MPH, MS-HCM,"— Presentation transcript:
1 Seasonal Influenza versus Avian Flu and Public Healths Role : Content adapted for BugLine from presentation by : Cassandra D. Youmans, MD, MPH, MS-HCM, FAAP District Health Director East Central Health District VI
2 Epi Terms (www.healthyamericans.org) Epi Terms (www.healthyamericans.org) Endemic – expected or usual occurrence of disease Epidemic – unexpected or unusual occurrence of disease Pandemic – epidemic, but wider geographic area and larger population affected Shift – big change in a virus strain due to mutation Prevalence – existing disease in a given population at a given time Incidence – rate of occurrence of new cases of disease in a population Transmission – any means of spreading infectious disease to or among people Antigen – protein, usually foreign, that elicits a specific immune response Antibody – protein in the blood produced after exposure to an antigen Parasite/pathogen/germ – any organism causing disease Immunity – not susceptible to infection or disease Vaccine - a drug intended to induce active artificial immunity against a pathogen. It can be live or dead
3 Active Immunization (www.swinton.net) Attenuated (weakened) versions or strains of the pathogen –One dose typically induces a full antibody response or memory –Example: MMR vaccine from wild strains of measles/mumps/rubella viruses that are repeatedly passed through cell lines until non-pathogenic Killed (dead) versions or strains of the pathogen –Whole pathogen; examples: Salk polio strain and pertussis vaccine –Highly immunogenic part of the pathogen (toxoid vaccines) –These do not multiply in the host; multiple doses are typically given to induce a full antibody response.
4 Passive Immunization (www.swinton.net) Passive immunization is different –Concentrated pathogen specific antibodies (not weak or dead virus) are given to lesson the signs and symptoms of an infection or to provide short-term protection for several months –Does not induce memory needed for long term protection
5 Influenza Virus (Red Book 2003) Influenza Virus (Red Book 2003) 3 virus/antigen types (A,B,C) –Each has subtypes –Only three subtypes known to be currently circulating among humans: H1N1, H1N2, H3N2 (www.bt.cdc.gov) Epidemics are caused by types A and B –Antigenic shift has occurred only with Influenza A Antigenic shift - Major changes in these antigens lead to the emergence of new strains of the virus (the body cannot recognize or respond to the virus from past years) –Influenza B is slower to change and has no subtypes Antigenic drift – Minor changes cause seasonal epidemics (the body can still recognize and respond to the virus based on past years)
6 Clinical Symptoms (www.healthforums.com) Fever Cough Sore throat Muscle aches Eye infections Pneumonia Severe respiratory distress Life threatening complications Young infants – sepsis-like symptoms, croup, bronchiolitis, pneumonia Use Tylenol for children! Avoid Reyes Syndrome (associated with aspirin use, Influenza B, non-vaccine chickenpox.
7 Seasonal Influenza Spread in Humans Person to person spread via secretions or direct contact with contaminated surfaces Most infectious 24 hours prior to symptoms 1–3 day incubation period Attack rate depends on immunity within the community
8 Higher Risk Groups Cancer Diabetes Asthma COPD Cystic fibrosis Infant BPD (Bronchopulmonary dysplasia) Congenital heart disease Sickle cell and other red cell shape abnormalities
9 Diagnostic Tests (Red Book 2003) Nasopharyngeal (NP) swab/aspirate –Rapid screening test is reliable (sensitivity 45-90%, specificity 60-95%). Can culture in the first 72 hours of illness –Virus concentration decreases after 72 hours –Egg or cell culture isolates virus within 2–6 days Can get 2 antibody titers –A 4-fold increase in titer from acute to convalescent stages of illness is diagnostic
10 Current Treatment Recommendations For Type A and B Influenza (Tarascon Pocket Pharmacopoeia 2005) For treatment of Type A and B infections Begin within 2 days (48 hrs) of symptom onset Oseltamivir (Tamiflu) –For prophylaxis, not 100% effective –Indiscriminate use may cause viral resistance Zanamivir (Relenza) –Not for prophylaxis, not for young children
11 Pandemics (Pandemic Flu: What you should know. Q & A Volume I Winter 2006) An average of 3 occur every century Five in the last 120 years –1889, 1900, 1918, 1957, (Spanish Flu, million died, 500,000 in US 1957 (Asian Flu, 4 million died) 1958 (6 million died) Lower mortality because antibiotics available to treat secondary bacterial infections
Pandemic: Asian Flu (Pandemic Flu: What you should know. Q & A Volume I Winter 2006) –April 1957, a strain of influenza infected 250,000 people in Hong Kong –US researcher, Maurice Hillerman, predicted the start of the Hong Kong outbreak signaled the next pandemic –During the next 5 months, he persuaded 6 drug companies to produce influenza vaccine against the strain circulating in Hong Kong –The virus entered the US in September 1957, 20 million people infected, 70,000 died –Lesson learned: If enough vaccine is made in advance of a pandemic, lives will be saved
13 Pandemics (Pandemic Flu: What you should know. Q & A Volume I Winter 2006) –The best way to protect against a pandemic is a vaccine –The vaccine will have to contain the strain of influenza virus that is causing the problem –An effective vaccine cant be developed until the pandemic begins –4 companies make influenza vaccine Sanofi Pasteur, GlaxoSmithKline, Chiron, and MedImmune –There is limited infrastructure to produce large quantities of vaccine, therefore the vaccine would be rationed –Department of Health and Human services is developing a plan (www.pandemicflu.gov/plan)
14 Avian Influenza or Bird Flu (www.bt.cdc.gov)(www.healthyforums.com) Type A Influenza Virus principally found in, and occurs naturally among birds –Seasonal flu among birds H5N1 spreads rapidly among birds, but rarely in humans –Wild birds carry the virus in their intestines, but rarely get sick –Domestic birds - chickens, ducks, turkeys can get very sick and die –1997, Public Health Officials detected the strain in Southeast Asia, 170 people infected, 50% (85) died In affected countries, the virus has spread to other mammals like pigs, cats, and tigers.
15 Domestic Birds (www.bt.cdc.gov) Low virulence form - mild symptoms like ruffled feathers or drop in egg production High virulence form– spreads rapidly through flocks of poultry with mortality rates 90 to 100% in 48 hours
16 Transmission in Birds (www.healthforums.com) Infected birds shed virus in their saliva, nasal secretions, and feces Other birds are infected via direct contact with these secretions or excretions, or contaminated surfaces (cages, water, or feed)
17 Avian Flu Spread in Humans (www.healthforums.com) Direct contact with infected poultry or contaminated surfaces Risk factor – poultry worker, hand butchering infected foul Rare reports of the virus spreading from one person to another, and these cases have not been seen to continue beyond one person
18 US Department of Agriculture Guidelines - Common Sense At Home (www.healthforums.com) –Wash hands with warm water and soap for at least 20 seconds before and after handling food –Keep raw poultry and its juices away from other foods –Keep hands, utensils and surfaces such as cutting boards clean –Uses a food thermometer to ensure poultry has been fully cooked
19 Bird Flu and Humans (www.bt.cdc.gov) Prior to 1997, no human death associated No evidence that properly cooked poultry or eggs is a source of infection No human infections from eating poultry in affected countries H5N1 has not been detected in the US There have been no cases of infected poultry in the US In 2004, the US banned import of poultry from countries affected by Avian Influenza
20 District VI Public Health Department Focuses on Health and Wellness Medical ServicesEnvironmental Health Emergency Preparedness Promote Protect Provide 3Ps
21 Public Healths Principle Role in Disaster Mitigation To assure access to Special Needs Shelters (SNS) when needed To directly administer or provide for administration of agent specific prophylactic and/or therapeutic pharmacologys to mass populations To support local and district EOC emergency preparedness efforts
22 Pre Event: Is ALL about education! Preparation begins with education prior to a disaster Seek information about potential hazards within your community. Then you can: Secure your safety Secure your family and home Encourage friends, peers, community to do the same Plan for two-way communication with emergency personnel and family, and have contingencies built in Be flexible Be prepared
23 Public Health Challenge Risk of a shift: H5N1 virus might exchange genes with a human virus strain or mutate into a form that is easily spread to and among humans Rare in humans, therefore our immune systems have not been exposed to be able to develop enough of an immune response to fight it, an influenza pandemic could begin –The seasonal human influenza vaccine will not provide protection –H5N1 specific vaccines have been in development since April 2005 –Clinical trials are underway –Antiviral drugs are being studied for efficacy
24 Pandemic Flu Impact Assumptions (Pandemic Flu Response Standard Operating Guide (SOG) Pandemic Flu Impact Assumptions (Pandemic Flu Response Standard Operating Guide (SOG) Assuming Georgia makes up approximately 3 % of the US Population, Estimated population is 9.1 million
25 Consider the expected impact on area finances and infrastructure due to flu illness, absentees, deaths!
26 Disasters vary, but planning questions remain the same Who? What? Where? When? How? Why? Drills Offer Opportunities to Exercise Plans, Modify, and Adjust.
27 Successful Disaster Management Requires Partnership & Integration Volunteer Medical Reserve corps Local emergency operations centers Academic medical centers Community health centers Federally Qualified Health Centers Faith based organizations Nursing schools ESF8
28 East Central Health District Collaborators: Melba McNorrill, RN Child Health Coordinator Gary Zgutowicz, Emergency Preparedness Coordinator Donna Scott, Clinical Services Coordinator Sadie Stockton, TUPS/Chronic Disease Prevention Coordinator Jodie Reece, IT Director Helen Smith, Administrative Assistant to the District Health Director County Facility Managers and staff Contacts: Georgia Department of Human Resources, Division of Public Health; East Central Health District Emergency Preparedness ; East Central Health District, Centers for Disease Control and Prevention; ; www.cdc.gov